stock L98
Thread Starter
Racer
Joined: Jun 2006
Posts: 477
Likes: 1
From: Jefferson Georgia
stock L98
Hey guys I'm looking to supercharge my 88 A4 coupe, looking for decent boost with a stock L98. I have no plans of getting into the engine, just bolt on and go returning to stock if needed. True dual exhaust with h pipe, no cats, beefed rebuilt tranny and 2500 stall. Factory ecm. Needs to be steetable as it's my daily driver.
1. What would be a safe boost pressure?
2. What gains would be realized with that pressure?
3. What would the timing need to set to?
Thanks for any input, Jay
1. What would be a safe boost pressure?
2. What gains would be realized with that pressure?
3. What would the timing need to set to?
Thanks for any input, Jay
Drifting
Joined: Dec 2005
Posts: 1,309
Likes: 20
From: Woodstock Georgia
That's a nice kit...
This one's not so bad either
http://forums.corvetteforum.com/show....php?t=1634501
1. You could run safely run 8-10 psi of boost on a stock bottom end...obviously 8 is going to be safer than 10, but I'm running 10 with no problems (other than a tired 135,000 mile engine).
2. That psi range will get you somewhere around 400-450+ chp, depending on tune.
3. I run 6* initial advance with the alky injection and a programmed 5* spark curve retard at WOT.
This one's not so bad either
http://forums.corvetteforum.com/show....php?t=1634501
1. You could run safely run 8-10 psi of boost on a stock bottom end...obviously 8 is going to be safer than 10, but I'm running 10 with no problems (other than a tired 135,000 mile engine).
2. That psi range will get you somewhere around 400-450+ chp, depending on tune.
3. I run 6* initial advance with the alky injection and a programmed 5* spark curve retard at WOT.
Team Owner
Joined: Jan 2007
Posts: 45,861
Likes: 94
St. Jude Donor '08-'09
That's a nice kit...
This one's not so bad either
http://forums.corvetteforum.com/show....php?t=1634501
1. You could run safely run 8-10 psi of boost on a stock bottom end...obviously 8 is going to be safer than 10, but I'm running 10 with no problems (other than a tired 135,000 mile engine).
2. That psi range will get you somewhere around 400-450+ chp, depending on tune.
3. I run 6* initial advance with the alky injection and a programmed 5* spark curve retard at WOT.
This one's not so bad either
http://forums.corvetteforum.com/show....php?t=1634501
1. You could run safely run 8-10 psi of boost on a stock bottom end...obviously 8 is going to be safer than 10, but I'm running 10 with no problems (other than a tired 135,000 mile engine).
2. That psi range will get you somewhere around 400-450+ chp, depending on tune.
3. I run 6* initial advance with the alky injection and a programmed 5* spark curve retard at WOT.
Racer
Joined: Jul 2006
Posts: 319
Likes: 0
Not trying to threadjack. I also have a L98, but mine is a '91 model. My car came with new exhaust(I think flowmaster), chip, 160* thermostat and K&N. I'm thinking that if I can get the extra money within a year, I would like to add a SC. What does everyone recommend for that model L98? It's an auto with 2.54 or something gears.
Le Mans Master
Joined: Jun 2002
Posts: 6,883
Likes: 2
From: www.corvetteflorida.com
St. Jude Donor '03-'04-'05-'06-'07
Another approach you might want to consider is nitrous. The cost of a supercharger is high realtive to the value of your car (the C4 parts section has one listed for $3500). There is (was??) also a nitrous kit for sale there listed at $550. If /when I feel the need for speed, I'll probably go nitrous.
It's like someone else here said though, the biggest problem with nitros (other than the damed stuff going BOOM!!) is...it runs out
Air is free
Instructor
Joined: Mar 2007
Posts: 117
Likes: 0
From: San Luis Obispo California
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Le Mans Master
Joined: Jun 2002
Posts: 6,883
Likes: 2
From: www.corvetteflorida.com
St. Jude Donor '03-'04-'05-'06-'07
I'm not trying to be a smarta$$ when I say this, but do a little searching and you'll see what I mean.
Watch your bottle temps or BOOM!!
There goes the back half of your car
Melting Slicks
Joined: Nov 2000
Posts: 2,469
Likes: 6
From: Winchester Ontario
That's why a lot of kits have a blow off tube, in case bottle temps get too high, it safely blows the one seal and vents the nitrous outside your car, am I wrong? I know I have a blow off tube.
Intermediate
Joined: Mar 2007
Posts: 40
Likes: 0
even without a blow off tube it wouldn't matter, the valve would just release and let out the gas until it was at an atmospheric equilibrium.
I had an 89 Trans Am with a full nitrous setup, car went up in flames melting the rear bumper and whole entire car with a full tank of nitrous, when the bottle was pulled it weighed less and was black and grey, no explosion.
From what I have heard though the vette L98 got forged pistons as opposed to the f bodies, is that true at all?
I had an 89 Trans Am with a full nitrous setup, car went up in flames melting the rear bumper and whole entire car with a full tank of nitrous, when the bottle was pulled it weighed less and was black and grey, no explosion.
From what I have heard though the vette L98 got forged pistons as opposed to the f bodies, is that true at all?
Safety Car
Joined: Apr 2001
Posts: 3,525
Likes: 2
From: Houston TX
even without a blow off tube it wouldn't matter, the valve would just release and let out the gas until it was at an atmospheric equilibrium.
I had an 89 Trans Am with a full nitrous setup, car went up in flames melting the rear bumper and whole entire car with a full tank of nitrous, when the bottle was pulled it weighed less and was black and grey, no explosion.
I had an 89 Trans Am with a full nitrous setup, car went up in flames melting the rear bumper and whole entire car with a full tank of nitrous, when the bottle was pulled it weighed less and was black and grey, no explosion.
In the example just above, following the back half fire in the TA the N2O bottle was less than full, as the temps generated during the fire raised the bottle pressure and thus relieved the PSV (psi safety valve), preventing the actual bottle from exploding. So, in effect the PSV did exactly what it was intended to do.
So as is evidenced by the TA fire example above, do not blame N2O for something that it did not cause.
Aaron
Le Mans Master
Joined: Jun 2002
Posts: 6,883
Likes: 2
From: www.corvetteflorida.com
St. Jude Donor '03-'04-'05-'06-'07
Somewhere on here (IIRC?) Theres a pic of a vette that lost the back end to nitrous. I'll see if I can find it when I have the time.
Anyway, back to the discussion, I'd stay with the turbo for max HP or go SC for immediate SOTP thrills.
Anyway, back to the discussion, I'd stay with the turbo for max HP or go SC for immediate SOTP thrills.
Intermediate
Joined: Mar 2007
Posts: 40
Likes: 0
Just to clarify, I dont know exactly who the post by AKS Racing was directed to but I was trying to say or at least let people infer exactly what AKS Racing stated, and the guy with a nitrous explosion in the back could not have been directly from the gas exploding in the bottle, unless it was some freak one in a million occurence.
anybody know if there was any piston differences for the vette L98?
anybody know if there was any piston differences for the vette L98?
Safety Car
Joined: Apr 2001
Posts: 3,525
Likes: 2
From: Houston TX
My understanding is that '85 vettes had forged pistons, while the '86 and later L-98s did not.
My comments were directed at those who seem to think that N2O is going to cause the back half damage that some have posted on here. I used your TA fire as an example that supports the PSV function.
Aaron
My comments were directed at those who seem to think that N2O is going to cause the back half damage that some have posted on here. I used your TA fire as an example that supports the PSV function.
Aaron
Le Mans Master
Joined: Jun 2002
Posts: 6,883
Likes: 2
From: www.corvetteflorida.com
St. Jude Donor '03-'04-'05-'06-'07
I suck at posting pics, but here's a copy of the article and pics of the damage caused by Nitrous. You judge for yourselves.
http://images.google.com/imgres?imgu...004-47,GGLD:en
http://images.google.com/imgres?imgu...004-47,GGLD:en
Drifting
Joined: Feb 2004
Posts: 1,277
Likes: 1
From: Santa Maria CA
I love my small roots on my 69chevelle,never need a refill and is quiet. I floor the damn thing all over the place and it holds together if its done right. Same goes with nitrous though,done right it works great! My buddy and I go back and forth at the track with blower v.s. nitrous.
