NSW Corvettes
General Discussion Area => Corvette Related Chat => Topic started by: mrvett on June 22, 2006, 04:56:47 PM
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hey there people...i own an 87corvette convertable which is basically stock with auto trans. the performance work which i hav done includes straight through mufflers, removed the two pre cats but kept the larger cat in the middle, installed a 3.73gear ratio, cold air induction, 52m throttle body, and an adjustable fuel reg.
i went to the mechanic an put her on the dyno an she only made 136rear wheel kw. :P
does anyone know if these figures are normal for the amount of work or little work she has had done?
i found this a very low figure..im actually kinda scared to run her on drag strip
how much do your cars make? espically the c4's out there, also if anyone has run their car down the strip an got times an details that wld b great
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stock they should make about 150rwkw(200rwhp)
mine makes just over 400rwhp.and covers the 1/4 in the high 11's.
but i think that there is definately something wrong with yours.
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It's all about you,you,you - Any chance to gloat hey Bosch! "mine has 400rwhp" na na na!
;53
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hey 69dr how come your dragging the chain?
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Originally posted by 69 DIRTY RAT
It's all about you,you,you - Any chance to gloat hey Bosch! "mine has 400rwhp" na na na!
;53
you live in hope that one day you to can play with the big boys;46;46;46;46
it is all about me me me me me me me me me;laugh;laugh;laugh
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I'd expect a late-ish L98 to dyno up to 220(ish)RWHP based on what I've seen. (For once Boschie is being conservative with something (as opposed to going all-out ;41)).
ET-wise, most stock or basically stock auto L98's in good tune I've seen seem to be capable of 14.0-14.5 second ET's.
I'd check the basics first, timing, fuel pressure, good spark to all plugs, etc.
From what I understand, a 52mm throttle body is pointless with basic mods (I have one too but if I did it again I wouldn't have done it so early).
Before you look at more mods I'd be looking to find why your output is so low - which I guess would be a basic tuning issue.
I'd also ask what sort of dyno was used (and if it was a Dyno Dynamics dyno - was it in "Shootout Mode") when your power run was made?
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Go and check the basic's first, do a comp test as low comp = low power output
you can't tune an engine unless the comp is spot on and if someone is trying too they are ripping you off
My very stock 98 with a full tank of fuel did 14.0
I have never put it on a dyno and can't give you a hp figure, i was happy with 14.0
Decide what your happy with a high hp reading on a dyno or a low 1/4 time
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My 91 conv L98 at our dyno day put out 206 rear wheel hp
and at the drags on a wedensday night my best was a 14.003 @ 95.79mph or 154.1 kph
This car is stock standard (with C5 wheels);54
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Since we are on the subject of performance slugs i have never seen any of the RAT PACK post a time better than boschvette's 11.7 in a small block
i thought the rat pack were leaders not followers hahahahaha sorry
untill one of the rat pack members inprove on this time they should all turn up to club meetings in skirts any colour would be nice or better the time, its time to put up or ........... iron your skirts for the next meeting
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If you refer back to The RAT PACK rules and regulations, although quick times are good they are not a must! Only meeses have to prove themselves. When you are cool why try and prove it! Does the Primeminister have to constantly prove he is the Primeminister? Its the same situation....we have nothing to prove....we are at the top of the food chain! I can bring up the laws of averages if you like! Well the fact that 1 mouse is fast and the rest of you guys are slow...it doesnt look good for you meeses! If you average big block times you will see that most Rats will beat most small blocks! ;41;37
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Hey Hey....wow....this has become a rather interesting thread..... another bigblock Vs smallblock or is that smallblock great 1/4 mile times, awaiting bigblock to prove itself yet again....;48
M;36
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it has only taken 1 mouse to bring down the rat pack, possible the first of many
untill the rat pack responds will we see all of you in nice new skirts at the next meeting
dont leave it to the last minute to go shopping
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the silence from the rat pack shows weakness,follow me my children as we are about to rule the world;54;54;54;54;54;54
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Any stock 85-87 I've seen has never had more than 200 rwhp (same dyno). Mine only made 198 with no MAF screens (that mod is worth 4 rwhp). Mine did 14.2 (with 3.07 gears)on the 1/4 just bprior to blowing it up in Melbourne. It now does 13.6 with no traction.
You won't get much without at the least a decent dual exhaust. A new cam, intake and headwork will drop you up to a second ET.
What pressure are you running your fuel reg? Did you set it on the dyno?
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Hey, Hey looks like us Rats are gonna have to hi-jack this thread and lay down some facts. 99 out of every 100 Power thumping, Gaz Guzzlin, Tyre Frying, Neck Snapping Big Blocks runs the quater in 13 seconds and under and puts out an average of 300RWHP. Given the fact also that most big blocks are vintage with an average age of 35 years where do all you 1990 and later models get off. As for your remark SC for wearing a skirt to the next meeting it is ironic that you know so much as to iron it first, something of experience one would imagine given your lifetime membership to the Mice Inc. of Australia. I always thought the skirts I saw on your clothesline were CC's or your daughters but obviously I was wrong and clearly they are mearly your Mice Inc. Club Uniform.;41;41;41;41;41;41
:20:20:20:20:20:20
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Originally posted by 77CVT
Any stock 85-87 I've seen has never had more than 200 rwhp (same dyno). Mine only made 198 with no MAF screens (that mod is worth 4 rwhp). Mine did 14.2 (with 3.07 gears)on the 1/4 just bprior to blowing it up in Melbourne. It now does 13.6 with no traction.
You won't get much without at the least a decent dual exhaust. A new cam, intake and headwork will drop you up to a second ET.
What pressure are you running your fuel reg? Did you set it on the dyno?
no didnt set fuel reg on dyno...but i took her to track a while ago before i changed gears ratio to 3.73s, throttle body 52m, cold air, an fuel reg an she ran a 14.60. now thats slow but i didnt think that bad for stock. i wil def run her as soon as i can an let u's all kno
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no didnt set fuel reg on dyno...but i took her to track a while ago before i changed gears ratio to 3.73s, throttle body 52m, cold air, an fuel reg an she ran a 14.60. now thats slow but i didnt think that bad for stock. i wil def run her as soon as i can an let u's all kno [/quote]
Hey Mr Vette, don't feel too bad about the times, its most likey a timing thing.
Anyway, you would most likely definately whip my ass in the quarter... as mines probably a lot slower than yours.
M;36
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I was wondering who the snow dropper was a few things have gone missing from our cloths line
dont try and change the subject put up or look nice at the next meeting
how many of the rat pack will be wearing heels with their skirts
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Ok. Now I was asked to give a little more latitude for off topic comments in threads. I think I've been pretty good.
But out of 18 post's in this thread, 11 are off topic. Fair is fair guys. Consider the poor guy who is trying to learn something here.
Call me a wet blanket but someones got to do it. And at the moment that someone is me.
So how about it lads?
Cam
Forum Admin;42[/i]
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:o
Hey mrvet.
I bet my slug is slower than your slug, also my slug is biggggggger than your slug.
:grr :mmm :b4 :grr
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;48
Oops sorry Cam
I didn't see your post.
:mmm;43;mmm
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no didnt set fuel reg on dyno...but i took her to track a while ago before i changed gears ratio to 3.73s, throttle body 52m, cold air, an fuel reg an she ran a 14.60. now thats slow but i didnt think that bad for stock. i wil def run her as soon as i can an let u's all kno
You should go lower than that. Practice with different launch rpm's. I can't launch over 800rpm or it goes sideways into 2nd. Mind you I have crap tyres.
Are you holding 3rd gear or into o/d? with 3.73 gears I would have though you could go into o/d briefly.
Mr69er, I do 13's and is older than a 90. Can I get away without a skirt? Don't make me spend more $$ and come down there and kick your high 12's azz!! ;--
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Originally posted by 77CVT
no didnt set fuel reg on dyno...but i took her to track a while ago before i changed gears ratio to 3.73s, throttle body 52m, cold air, an fuel reg an she ran a 14.60. now thats slow but i didnt think that bad for stock. i wil def run her as soon as i can an let u's all kno
You should go lower than that. Practice with different launch rpm's. I can't launch over 800rpm or it goes sideways into 2nd. Mind you I have crap tyres.
Are you holding 3rd gear or into o/d? with 3.73 gears I would have though you could go into o/d briefly.
Mr69er, I do 13's and is older than a 90. Can I get away without a skirt? Don't make me spend more $$ and come down there and kick your high 12's azz!! ;--
mrvett, there are alot of variables in getting a car down the quarter so don't consider that the be all and end all at this point (as a side note (and I am open to correction here) I hope you aren't using much more than around 4500rpm before shifting as when my top end was stock I found that didn't help).
Just check the basics like timing, compression, ignition and fuel pressure and then go from there. With your gearing & mods and a good tune you have a fair bit more in the car as it is before you do any other mods in my opinion.
p.s. - 77CVT, I don't think any of the Ratpackians have set an ET starting with a 12 yet (not that I can talk). ;53
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is it worth while trying to set up a day where we could check compressions and ignition timing
a lot of people forget the basic's and there not hard to do
most people know how to do a comp test and timing but just dont have the equipment
the club is about helping each other well here's a chance
I can get hold of timing light, comp gauge and vacuum gauge and fuel pressure gauges
what does everone think
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sorry cam for getting off the subject
its the rat packs fault
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Originally posted by SC
is it worth while trying to set up a day where we could check compressions and ignition timing
a lot of people forget the basic's and there not hard to do
most people know how to do a comp test and timing but just dont have the equipment
the club is about helping each other well here's a chance
I can get hold of timing light, comp gauge and vacuum gauge and fuel pressure gauges
what does everone think
A group fault finding day. Not a bad idea and we might be able to solve our friends problem with some hands on work.
I was trying to organise something like this with Scott at Corvette Alterations in August but we only had 1 or 2 takers. We needed 20 for it to happen. CLICK ME (http://www.nswcorvettes.com.au/forum/viewthread.php?tid=3152)
May be we could still organise it and implement these basic lessons into it as well.
We would have a venue and Scott said he would put the food on.
Just a thought.
But I do like your idea.
Cam ;42
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p.s. - 77CVT, I don't think any of the Ratpackians have set an ET starting with a 12 yet (not that I can talk). ;53
I thought he snuck in with a 12.8 or 9 at your last drag day? No doubt he'll jump in a correct me if I'm mistaken! ;-)
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there was a 12.9 set by a big block but i dont think he is part of the rat pack
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77CVT, I don't think any of the Ratpackians have set an ET starting with a 12 yet (not that I can talk). ;53 [/quote]
vo i have seen you run a mid 12 and you did it easy
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As they say , when the flag drops the BS stops and the BS is thick on the ground round here from the Rat pack dribbling.
Other than Steve ( SR ) distinctive lack of BB Vettes seen at dragstrip.
Lots of "I've got a squillon Hp and a big dick" but not prepared to put their money where the mouth is against a few little mice motors.
It must be that magic voodoo
"If I take my car to the strip I might break something".
How about a little DYO?
Mice motored Vette's won both classes at the last V8 Owner's track day ,rat powered cars very welcome to attend.
'87 C4, A4 3.07.
100,000 mile heads never been off L98.
12.98X in street trim. 1.75 60 ft
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has a member of the rat pack ever ran at the drags ever? and who was it
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Originally posted by SC
has a member of the rat pack ever ran at the drags ever? and who was it
We're getting a little off track here but for what it's worth the only Rat Pack member to run at the drags is MR69ER. ;42 to him for getting out there and having some fun - which is what this whole "us vs them - Rat Pack vs the Mice" thing is about. ;-)
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yes we are off track again
mrvett have you done a comp test and what are the results as i am curious
you never said how many km/miles are on the clock
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what colour is the car ?
it must not be red,cause red ones go faster,
you could understand if it was a banana coloured rat powered vette and it lacked grunt.
(sorry can not help myself);43;43;43;43;43
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Thats strike One. ;53
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I think that a discussion day like the one suggested would be great, it wpould allow us all to get more familiar with the car we own & share experiences etc
Should it be raised at the next meeting as it could be a regular thing?
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Originally posted by SC
yes we are off track again
mrvett have you done a comp test and what are the results as i am curious
you never said how many km/miles are on the clock
havnt done a comp test...118,000mile on clock
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Originally posted by BOSCHVETTE
what colour is the car ?
it must not be red,cause red ones go faster,
you could understand if it was a banana coloured rat powered vette and it lacked grunt.
(sorry can not help myself);43;43;43;43;43
boshie it is red but jst a red pig in fact ;41
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ok ok...i went to calder park last night in melb cause thats were mrvett lives. now all i wanted was to run a 13second quarter. all i got though was a 14.02 at 95.32mph.
now i am a little disaponited but i did feel better when my mate geoff reminded me my car didnt do that well on the dyno to begin with..haha
so i reckon it aint bad for a stock 87engine with jst a throttle body, fuel reg, exhaust, and 3.73gear ratio...but i stil want that 13 :b4 ;laugh
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"straight through mufflers, removed the two pre cats but kept the larger cat in the middle "
Something is wrong.
My original '87 engine 120,000+ miles with no pre cats ,hiflow main cat and eliminators went 14.0 -14.1 with stock 3.07s.
Taking out the main cat dropped it to 13.9.
With a stock TPI and 3.73s I would guess you have no useful revs in 1st and be running out of revs in 3rd across the line.
What cond is your main cat in?
Does the engine rev freely under load?
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I would consider a high 13 or low 14 to be OK for your Vette
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Originally posted by mrvett
ok ok...i went to calder park last night in melb cause thats were mrvett lives. now all i wanted was to run a 13second quarter. all i got though was a 14.02 at 95.32mph.
now i am a little disaponited but i did feel better when my mate geoff reminded me my car didnt do that well on the dyno to begin with..haha
so i reckon it aint bad for a stock 87engine with jst a throttle body, fuel reg, exhaust, and 3.73gear ratio...but i stil want that 13 :b4 ;laugh
That's about right. Mine does 13.6 @ 101mph. With those gears you need to make it breathe and you'll nail it easy!
;42
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Originally posted by 87Z51
"straight through mufflers, removed the two pre cats but kept the larger cat in the middle "
Something is wrong.
My original '87 engine 120,000+ miles with no pre cats ,hiflow main cat and eliminators went 14.0 -14.1 with stock 3.07s.
Taking out the main cat dropped it to 13.9.
With a stock TPI and 3.73s I would guess you have no useful revs in 1st and be running out of revs in 3rd across the line.
What cond is your main cat in?
Does the engine rev freely under load?
honestly not sure wat cond of main cat is like? engine seems to rev alright, i thought i would run out of revs much quicker
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Originally posted by Garry Smith
I would consider a high 13 or low 14 to be OK for your Vette
I'd agree but with the 3.73's in an auto car I'd expect a little better - maybe consistent 13.XX ET's (with everything else being equal/up to the task).
Is it me or does the MPH look a little low guys?
What was your 60ft time mrvett?
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I'm not up on these beast's but thought I would pass this on.
Some body mention to me that it might be worth checking that main cat. He said that they were known for fouling up. Just food for thought.
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The main cat is prone to collapsing and will progressively block the exhaust.(i had this problem once).
A mild or stock L98 should run closer to 100mph.
Could be running into the L98 out of breath zone with those 3.7 gears.
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Originally posted by mrvett
Originally posted by BOSCHVETTE
what colour is the car ?
it must not be red,cause red ones go faster,
you could understand if it was a banana coloured rat powered vette and it lacked grunt.
(sorry can not help myself);43;43;43;43;43
boshie it is red but jst a red pig in fact ;41
:{ :{ :{:
:bold :bold :bold
Big yellow bananas
are more in demand and cost a lot more than
big red apples
what is the moral of this
;35 YELLOW is cool ;27 ;27
:pinki red;54
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Originally posted by Vette Obsessed
Originally posted by Garry Smith
I would consider a high 13 or low 14 to be OK for your Vette
I'd agree but with the 3.73's in an auto car I'd expect a little better - maybe consistent 13.XX ET's (with everything else being equal/up to the task).
Is it me or does the MPH look a little low guys?
What was your 60ft time mrvett?
my 60ft time was 2.014
with a quarter mile time of 14.092 @ 94.93mph
u reckon its gettin sluggish in da top end?
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it is definately losing top end somewhere.put a broom stick through the cat and see how you go.
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Originally posted by mrvett
my 60ft time was 2.014
with a quarter mile time of 14.092 @ 94.93mph
u reckon its gettin sluggish in da top end?
In my opinion that is a good enough 60ft time for the ET you are running and for a stockish L98. I agree with Boschvette and others who say you are missing some top end.
In my opinion you should be doing around 99-100mph trap speeds.
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Originally posted by BOSCHVETTE
it is definately losing top end somewhere.put a broom stick through the cat and see how you go.
Why the cat and not the dog. Sorry couldn't help it. (If ya can't beat em, join em. Inside joke. SC will come in on this one for sure) ;53
Boshy,
Can he easily remove the cat and replace it with a section of pipe to test this?
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I agree with VO here, what you need to consider the L98 with the TPI rinners will lose it in top end torque, I think that if you are running mid to high 13's & around 95 to 100 mph would be fine.
There is nothing wrong with the 0 to 60 ft time, I feel that confirms it.
PS I would not think you cat is blaocked that much if at all, as Boschie said shove a broom stick up it after you remove it & tip it upside down to see what falls out
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hey cam have i got it right first push the broom up the cat & then turn it upside down & see what falls out? sounds like something that the rat pack would do.
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Originally posted by Cameron 77C3
Can he easily remove the cat and replace it with a section of pipe to test this?
Depends on how his exhaust was put together. Odds are for an 87 the cat is probably flanged at both ends so it would be relatively easy. Thing is, running a temporary "test pipe" instead of a cat at the track will see a performance increase over a stock cat so it won't be a true test if the stock cat is clogged (although I'm sure the visual test one can do in taking it off would be sufficient).
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hey guys jst lettin u kno cat has been removed dis morn..i wnted to take her to da strip 2nyt at calder but its been called off due to weather..hopefully next week
its no running no cats an straight through mufflers...it definatly louder an feels it picks up a lil better, the true test wil b at da track.
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hey there fellow corvette drivers jst wana lets u'z all know i was at calder park on friday night and recorded a 1/4 mile time of 13.83 at 96.37mph...very happy with this result..it probably could be a little quicker but 13s for a street car i think aint too bad ;46
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That's good! Looks like you got good traction.
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Good to hear you you got an improvement! It must have been fun giving her heaps down the track!
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Well done
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thanks boys...yea tractions was good an was great havin her out on the track again :)
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In respect to your concerns about power output .... Without wanting to be too controversial... what is important to you, horsepower or torque?
I have a 87 Convertible and a 94 Convertible ... the 87 puts out about 240 hp and 330 ft/lb of torque and the 94 puts out 300hp and 330 ft/lbs of torque...interesting huh....
the important part is when then produce those figures...
I got the 87 dyna'ed and to my surprise .... it turned up about 160 rwhp....as you would expect from an instrument which measures output via the rear wheels....but GM measures from the flywheel( and hence the 240hp).... but the plot thickens....because GM doesnt take into account accessories hanging off the engine.
Numbers... numbers.... numbers.... they are unimportant.... because what is important is what happens at the lights!
BOTH cars go 0-60mph in about 6 secs!! even though there is a 60 hp difference.
BECAUSE the thing which gets you mobile from a standing position is TORQUE..... which is the ability of your engine to TWIST around the rear wheels thru the drive shaft, gearbox and diff( which are both geared)....
In the 87 that torque is max'ed in the 3000-4000 rpm range... whilst the max hp comes on line about 5200-5500 range....
So I ask the question... to more knowledgable forum members....
which is more useable Torque or Horsepower?
and where?
at the traffic lights... where 95% of us drive?
or the drag strip ... where 5% of us drive?
cYa
daniel42au
http://members.ozemail.com.au/~daniel42au/
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which is more useable Torque or Horsepower?
and where?
at the traffic lights... where 95% of us drive?
or the drag strip ... where 5% of us drive?
Same situation either place.The torque is what gets you moving.
A L98 will out run a LT1 to 60mph on torque alone then
two things happen ;
the L98 with it's TPI intake runs out of breath and the LT1 with it's top end manifold comes on line.
Stock for stock a LT1 will run a faster time than a L98 but the L98 will probably run a better 60Ft.
Inherent problem for L98 cars is the torque is so big low down that traction becomes a problem especially in manual cars.
One of the few situations where it is benefical to bleed off some bottom torque so as not to spin up.
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Ok This brings me to a Question I've been wanting to know for a while.....When Racing either at the drags or on the track, IS it better to change gears at the highest torque or highest horsepower? to get the fastest out of the car?
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General rule of thumb is to shift at max HP so the engine revs will fall on to your peak TQ.
Repeat as necessary until you win the race....(or run out of gears);--;46
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Thanks, that makes sense!
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Realising the forumula for converting hp to kw and visa versa is:
Horse power (hp) ---> Kilowatts (kW): hp x 0.7457 = kW
Kilowatts (kW) ---> Horse power (hp): kW x 1.341 = hp
According to your dyno tuner, your car is puting out 182 hp at the rear wheels...
Chevrolet say your car was worth 240 hp at the flywheel when it left the factory 18 years ago... and this is probably without accessories....
The pundits say ya lose about 25% of power from engine to rear wheels.... due to gears, differential, accessories and such....
25% off 240 gives you 60hp... which leaves you with 180 hp.... hmmm....
Also, realise that your local dyno is an experiment of ONE... it may or may not be totally accurate.... it is like the set of scales ya weigh yourself with every morning... if ya want to know if your losing weight use the same scales every morning....it may not be accurate but it gives you a reference point.... but if ya want to lose weight without effort find a set of scales which weigh 5 lbs under .... :) but dont go back to it again. What I am saying is that no one goes around calibrating dyno's against a known output so who knows how accurate each one is....they are only reference points.
If you really wanna know where ya stand....my suggestion to you is don't be shy.... take it to the strip and have some FUN... cos the proof is in the seat of your pants... as others here have said if it aint pulling low 14's THEN ya know ya got a problem.
regards,
daniel42au
http://members.ozemail.com.au/~daniel42au/
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Point taken... but the point I draw between the lights and the strip is that at the street lights I am not behaving like a hoon with high revs.... when the lights change I just put the foot down from idle and let the slush box and the V8 do my torquing.... by the time 60-80kph comes around then I dont wanna play anymore.... because there is no law against nice accelleration. :-)
Originally posted by 87Z51
which is more useable Torque or Horsepower?
and where?
at the traffic lights... where 95% of us drive?
or the drag strip ... where 5% of us drive?
Same situation either place.The torque is what gets you moving.
A L98 will out run a LT1 to 60mph on torque alone then
two things happen ;
the L98 with it's TPI intake runs out of breath and the LT1 with it's top end manifold comes on line.
Stock for stock a LT1 will run a faster time than a L98 but the L98 will probably run a better 60Ft.
Inherent problem for L98 cars is the torque is so big low down that traction becomes a problem especially in manual cars.
One of the few situations where it is benefical to bleed off some bottom torque so as not to spin up.
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the problem that i have racing off the lights is that with high tyre pressure,cold tyres and the usual build up of oil and crap at the lights i just fry the back tyres into a cloud of smoke, so i tend to wait till the mid of 1st gear before i start to feed the power in.
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"I am not behaving like a hoon with high revs.... when the lights change I just put the foot down from idle"
No advantage with a L98 loading up the revs on the line.
At the strip I use the same launch technique I use on the street ;
off idle and nail it = 1.7 60fts
The only difference is how long I keep my foot into it.
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havnt read all posts,but i think gear ratio also has a lot to do with it.years ago i had a (dont laugh) a suzuki sierra 4wd,fitted with the big block 970cc 4 stroke,now this thing had 4:11 gears,and blew most things off at the light.hehe even a compresser mercedes....much to his disgust...hey it happens.but top speed was a killer 110kph.flat out.now if anyone has ever driven one of these thing off road,they will be amazed,low weight,killer low ratio and the abillity to out perform some serious off roaders..think patrols,landcruisers etc..... so how much DOES hp have to do with anything?.... im thinking gear ratios and torque....hp is great for top end stuff, but imagine 500 hp on the street? be real...i would rather be able to pull a wheelstand than run a 200+kph car.
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since my suzuki had the big block 970cc..do i get a membership to the rat pack?;39;39
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No advantage with a L98 loading up the revs on the line.
At the strip I use the same launch technique I use on the street ;
off idle and nail it = 1.7 60fts
The only difference is how long I keep my foot into it.
;51 Some good responses here.
1.7 is pretty good traction! ;46
Your ability to use torque is dependant on your tyres. Anything over idle fries mine, which is pretty cool until you can't see where you are going and then it snaps into second and sends you sideways. They hate it when I do that at K Mart!
Your stock intake runners will act as your rev limiter. You can build an L98 for HP but will be a dog over 5000 rpm - with stock runners it is better to have good torque t'out the rev range. (IMHO)
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"You can build an L98 for HP but will be a dog over 5000 rpm "
;51
I have siamized stock base ,SLP runners, ported plenum and headers on 100,000 mile engine.
Even with these mods still does not make power over 5000 RPM just makes a lot more than stock below.
The long runner setup, even modified does not lend itself to big revs but makes a sh#t load of bottom end torque.
As stated above it depends if you can get that torque down to the road.
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Are we talking about the same thing?
I am talking about traffic lights at the street... and just cruising off without making a scene... ie Revs and SMOKE... :-)
these are two different environments....
My L98 has not gone over 4000rpm except when I agreed to the dyno tuner wishes.... and he found my L98 was puting out the same HP as when it left the factory.... about 160 flywheel hp.
actually I envy you... 400 RWHP is more than enough to please anyone... male or female... AND as they say... what you can't put on the deck is a waste.
So pls share with us what you have done to get 400 RWHP out of an L98?.... and I am hoping that ya dont say ... "i got a crate engine" :-) ... cos I (and the originator of this post) have an L98 to improve without expending too many bucks for the bang....
daniel42au
http://members.ozemail.com.au/~daniel42au/
Originally posted by BOSCHVETTE
the problem that i have racing off the lights is that with high tyre pressure,cold tyres and the usual build up of oil and crap at the lights i just fry the back tyres into a cloud of smoke, so i tend to wait till the mid of 1st gear before i start to feed the power in.
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Originally posted by daniel42au
Are we talking about the same thing?
I am talking about traffic lights at the street... and just cruising off without making a scene... ie Revs and SMOKE... :-)
these are two different environments....
actually I envy you... 400 RWHP is more than enough to please anyone... AND as they say... what you cant put on the deck is a waste.
So can pls you share with us what you have done to get 400 RWHP out of an L98?.... and I am hoping that ya dont say ... "i got a crate engine" :-) ... cos I (and the originator of this post) have an L98 which I would like to improve without expending too many bucks for the bang....
daniel42au
http://members.ozemail.com.au/~daniel42au/
Originally posted by BOSCHVETTE
the problem that i have racing off the lights is that with high tyre pressure,cold tyres and the usual build up of oil and crap at the lights i just fry the back tyres into a cloud of smoke, so i tend to wait till the mid of 1st gear before i start to feed the power in.
daniel
about 18 months ago i blow the old motor up at a corvette drag day so i was in the market for a new motor.i purchased a 4 bolt main block and strocked it to 383 and flowed the alloy heads that were already on it and put a solid roller cam and so on and so on.but the main difference is that i run a miniram intake which is a aftermarket manifold that replaces the long runner TPI injection that you have,and allows me to rev to 6500-7200 if needed.although the motor makes around 500hp if i can improve the computer(eg haltech) and replace the mass air flow meter with a speed density system the engine builder said it should make 560-580hp which would give me about 450 rwhp.easily enough to smoke both supercharged and big block cars.
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Originally posted by daniel42au
Are we talking about the same thing?
Knowing Boschvette, I'd say the answer to that question is YES. ;46 ;41
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"he found my L98 was puting out the same HP as when it left the factory.... about 160 flywheel hp"
Should that not be RWHP?
stock L98s come from the factory 240- 245 flywheel Hp.
" share with us what you have done to get 400 RWHP out of an L98?"
Well it was a L98 once until he made it a 383 with miniram
"would like to improve without expending too many bucks for the bang".
From the weight v ET mine is making approx 320 at the flywheel.
Have ZZ4 cam , siamized stock unported base , SLP big tube runners and a home ported plenum with headers.(100K heads never been off)
Running the stock TB v a 58mm made no difference so save your money
Can only go so far with intake mods until you need a cam.
Best bang for buck is headers and a hi flow cat.
Then freebie intake mods ;siamized base works wonders without the big tube runners ,then a cam.
ZZ4 cam is nice can be had for under $250Au ( v $500 for a TPIS cam) and was fitted to ZZ4 crate engine which is a L98 with a carb rated at 355Hp so factory proven combo.
Will lose a little with TPI intake even modded like mine
Need to upgrade valve springs to suit cam ZZ4 / LT4 ones are cheap also.
"My L98 has not gone over 4000rpm"
time to put you foot down ,stock will make power to 4500 before it drops off.
Next?
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thanks for that.
yes, your quite right... 160 rwhp is what i meant.
maybe one can never have too much power... and it is only limited by the thickness of one's wallet.
as for me, I am in the process of making some fairly modest improvements... 1.6 gm roller rockers, SLP runners, BBK 52mm throttle body(the original was worn out), hei(?)ignition coil, and a stage 2 transgo shift kit.
I had replaced the original mufflers which were rusted out with a pair of magnaflow mufflers but being in QLD i enjoy driving with the top down too much and the increase in noise got to me so I subsequently replaced them with a pair of stock mufflers from corvette central.
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To optimise the 52mm you need to spend 1/2 hour with a die grinder removing the EGR ridges in the plenum behind the TB.
1.6s are a good mod but won't gain you much on the stock whimpy cam.
Will only take you out to .430 / .450 lift where as a stock LT1 cam alone is .447/.459 with 1.5s.
ZZ4 cam gives you .474 / .510 with stock rockers.
Great increase in power with nice street manners.
or match the 1.6s up with the proven Hot cam to get .525 /.525