1995 LT1 upgrades
Thread Starter
Le Mans Master
Joined: Dec 2005
Posts: 6,999
Likes: 1,685
From: Southeast TX
1995 LT1 upgrades
Just bought my wife a clean 1995 coupe with auto trans. Several buddies have seen through this ruse and correctly figgered out who the toy was really bought for. I argued that if it was really for me, it would have had a 6speed. They replied that the wife wouldn't have let me buy one she couldn't comfortably drive. They know me too well.
She has agreed to let me play with the motor a bit. Nothing that will make it too loud, rough, or unreliable. I'd also like to keep the fuel economy close to what it is now. I've done lots of work on small and big block chevys, but it's been 25 plus years ago. What I did to those motors, I'm sure, has no relation to what needs to be done to this one.
Can anyone suggest some upgrades to start with. I'm willing to spend about $2500 on the project. If this subject has been beat to death, maybe someone can direct me to the appropriate threads. I'm new to this site, and don't really know my way around yet. TIA.
She has agreed to let me play with the motor a bit. Nothing that will make it too loud, rough, or unreliable. I'd also like to keep the fuel economy close to what it is now. I've done lots of work on small and big block chevys, but it's been 25 plus years ago. What I did to those motors, I'm sure, has no relation to what needs to be done to this one.
Can anyone suggest some upgrades to start with. I'm willing to spend about $2500 on the project. If this subject has been beat to death, maybe someone can direct me to the appropriate threads. I'm new to this site, and don't really know my way around yet. TIA.
Thread Starter
Le Mans Master
Joined: Dec 2005
Posts: 6,999
Likes: 1,685
From: Southeast TX
Not opposed to doing something like that providing I can do the work myself and the hood etc doesn't have to be mutilated. I remember seeing supercharger installations years back that always involved a crappy looking hood scoop. The lines on the wife's vette are perfect in my eye and I don't want to change them.
Can you recommend a brand of supercharger to look at?
Just wished adding a few extra ponies to the vette was as easy as my DMax pickup. Programmer and exhaust has it over 375 very civilized HP. Gets better mileage too. I was hopeing a little more cam timing, a modified chip, and a little freer flowing exhaust would get me close to 375 on the vette.
Can you recommend a brand of supercharger to look at?
Just wished adding a few extra ponies to the vette was as easy as my DMax pickup. Programmer and exhaust has it over 375 very civilized HP. Gets better mileage too. I was hopeing a little more cam timing, a modified chip, and a little freer flowing exhaust would get me close to 375 on the vette.
Last edited by old motorhead; Dec 28, 2005 at 12:40 PM.
Racer
Joined: Jan 2004
Posts: 458
Likes: 1
From: NY
ATI ProCharger. I think they claim the highest HP and they also have a self contanded unit witch means they don'r run an oil line to the oil pan. Check around on the price. I think SuperChargers For Less might be the cheapest.
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
Originally Posted by rtracy
It will cost you a little more but will be very reliable, won't be loud, 50 to 55% more power, and will not change the driveability of it.
SUPERCHARGE IT!
SUPERCHARGE IT!
....but will probably burn through your $2500 budget in a hurry. Reliable, I'm not convinced, as these high rpm spinners seem to develop bearing problems. For starters, read Nathon Plemons pages on less aggressive mods:
https://www.wku.edu/~nathan.plemons/...rformance.html
also, get to know and love(NOT!), the many sensors used to feed your thirsty LT1 :
http://www.babcox.com/editorial/cm/cm69910.htm
I have heard of good results from the Vortex ramair setup:
http://www.speeddemonmotorsports.com...airfuelC4.html
Last edited by MikeC4; Dec 28, 2005 at 01:37 PM.
Thread Starter
Le Mans Master
Joined: Dec 2005
Posts: 6,999
Likes: 1,685
From: Southeast TX
Did a little checking around and the procharger seems to be the one several performance shops recommend for the wife's vette. $4400 for the self contained kit. $4100 for the kit where the blower is lubed with engine oil. Place in NW Louisanna will install it for another $1200. 8 intercooled psi ought to wake the LT1 right up. No hood mods. They said it would to 2 to 3 days to install. Might just bite the bullet and go this route. I'm wondering how reliable these blowers are. How long have they been around?
Thread Starter
Le Mans Master
Joined: Dec 2005
Posts: 6,999
Likes: 1,685
From: Southeast TX
If I go the blower route, the budget is definately shot. $ numbers are in a post above. Mr Plemons' writings were worth the time to read through. Interesting #'s on the stock cam in the LT1. Very similar to a crane cam I used in my 73 vette. Streetable, yet made quite a bit more upper rpm power. I may add some higher ratio rocker arms. That mod ought to make noticable power for not too much $. Easy installation too. Agree with you on the supercharger reliability question. I have turbo chargers on many diesel engines and they rarely give any trouble. Seems they ought to be able to make a supercharger that will go the distance. They have some side loads that a turbo doesn't have, but they don't have to deal with 1200 degree exhaust gasses either.
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Race Director
Joined: Jan 2002
Posts: 12,263
Likes: 86
From: O'Fallon Missouri
Originally Posted by old motorhead
Agree with you on the supercharger reliability question. I have turbo chargers on many diesel engines and they rarely give any trouble. Seems they ought to be able to make a supercharger that will go the distance. They have some side loads that a turbo doesn't have, but they don't have to deal with 1200 degree exhaust gasses either.
Le Mans Master
Joined: Feb 2002
Posts: 7,858
Likes: 2
Originally Posted by STL94LT1
The stock LT1 has 10.5:1 compression, and running boost on that much compression can be really hard on the head gaskets and engine internals.
The engine life will be reduced if all that is done is simply bolt on the blower. Need to at least lower the comp ratio some, 9.0 or 9.5. But there's more needs to be done to beef an engine up for boost.
I say go the heads/cam route if absolutely MUST mod it, but you will lose some MPG since the engine will be breathing more and thus the PCM will command more fuel.
I'd leave it stock, but that's me. My '95 has plenty of go, and its bone stock.
If you want to wake the car up some, I've got a $14.99 "mod" that will do it:
http://forums.corvetteforum.com/show...96&forum_id=48
It works. Stabilant would work as well or better, but that would make it a $67.99 mod...
Safety Car
Joined: Dec 2002
Posts: 3,655
Likes: 24
From: Charleston SC
"I'm willing to spend about $2500 on the project" "SUPERCHARGE IT!" 
Ask a couple of the guys in the FI section what the real cost of getting a blower on the car and running properly is, closer to 7-10K then 2.5 I promise. For your budget port the heads (add/ 1.6 R/Rs), cam and headers and exhaust if you find a couple extra bucks
Ask a couple of the guys in the FI section what the real cost of getting a blower on the car and running properly is, closer to 7-10K then 2.5 I promise. For your budget port the heads (add/ 1.6 R/Rs), cam and headers and exhaust if you find a couple extra bucks
Last edited by FD2BLK; Dec 28, 2005 at 03:21 PM.
Team Owner
Joined: Mar 2001
Posts: 30,856
Likes: 293
From: Boston, Dallas, Detroit, SoCal, back to Boston MA
Originally Posted by STL94LT1
IMHO, the best mod for around $2500 is heads/cam. Find a good head porter that offers a heads/cam package. I used CNC Cylinder Heads.
-Mike
-Mike
and that would just complement a blower if you decide to go that route later. BTW you might need a new trans coverter to go with that.
Thread Starter
Le Mans Master
Joined: Dec 2005
Posts: 6,999
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From: Southeast TX
I didn't realize that the compression was that high. Guess that's the reason for premium fuel. Compression that high with a blower added sounds like a sure fire recipe for an expensive disaster. The few gas powered blower motors that I have been around have had CR closer to 8.5:1. This project sounds as if will bump into the law of diminishing returns rather quickly. The LT1 apparently is a little too capable in stock form to have many areas that are easily upgradeable. The rocker arms and/or a cam change may be all that I'll do. Wouldn't take much more time to change the heads if that would be an upgrade cost/benefit wise. Back when I was building engines, to get the benefit of a head change, you had to have some pretty serious cam timing. Driveability and fuel economy suffered. When premium leaded was quite a bit under a dollar, who cared. Different now.
Race Director
Joined: Jan 2002
Posts: 12,263
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From: O'Fallon Missouri
Originally Posted by old motorhead
Back when I was building engines, to get the benefit of a head change, you had to have some pretty serious cam timing. Driveability and fuel economy suffered. When premium leaded was quite a bit under a dollar, who cared. Different now.
Thread Starter
Le Mans Master
Joined: Dec 2005
Posts: 6,999
Likes: 1,685
From: Southeast TX
Hey Stl 94lt1, tell me more. That sounds like a sweet set up. How'd you do it. Off the shelf heads or done by a custom grinder? What cam? What type of tuning? I'm all ears!
Race Director
Joined: Jan 2002
Posts: 12,263
Likes: 86
From: O'Fallon Missouri
Stock heads: CNC ported, bigger valves, Bee hive springs, Comp Cams Pro Magnum 1.6 RR
Comp Cams custom grind: 224/230 @.050 605/622 112+2
Stock Throttle body: bored to 52mm
EM Headers
PowerCat high flow cats
Flowmaster Force II cat-back
Meziere E. water pump
Impalla SS head gaskets: close to 11:1 compression
TPIS AFPR
4.10
Custom tuning by ME, with a little help from Tom Wong
Comp Cams custom grind: 224/230 @.050 605/622 112+2
Stock Throttle body: bored to 52mm
EM Headers
PowerCat high flow cats
Flowmaster Force II cat-back
Meziere E. water pump
Impalla SS head gaskets: close to 11:1 compression
TPIS AFPR
4.10
Custom tuning by ME, with a little help from Tom Wong
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
Originally Posted by old motorhead
They(superchargers) have some side loads that a turbo doesn't have, but they don't have to deal with 1200 degree exhaust gasses either.
Le Mans Master
Joined: Feb 2002
Posts: 7,858
Likes: 2
1.6 roller rockers alone are good for about 20hp at the crank, add a cam and then have the PCM tuned by a tuner, But if the car is an automatic transmission, ask around here first before just going out and buying the hotcam. I remember reading where some automatic trans LT1 guys went with a different grind than the hot cam to keep from sacrificing as much low end torque.
Originally Posted by old motorhead
I didn't realize that the compression was that high. Guess that's the reason for premium fuel. Compression that high with a blower added sounds like a sure fire recipe for an expensive disaster. The few gas powered blower motors that I have been around have had CR closer to 8.5:1. This project sounds as if will bump into the law of diminishing returns rather quickly. The LT1 apparently is a little too capable in stock form to have many areas that are easily upgradeable. The rocker arms and/or a cam change may be all that I'll do. Wouldn't take much more time to change the heads if that would be an upgrade cost/benefit wise. Back when I was building engines, to get the benefit of a head change, you had to have some pretty serious cam timing. Driveability and fuel economy suffered. When premium leaded was quite a bit under a dollar, who cared. Different now.
Thread Starter
Le Mans Master
Joined: Dec 2005
Posts: 6,999
Likes: 1,685
From: Southeast TX
Who makes the 1.6 rockers? How 'bout 1.7's? Is that overkill? Do you run into piston/valve clearance problems? Sure enjoy this site. There seems to be a bunch of folks that been there...done that.
Thread Starter
Le Mans Master
Joined: Dec 2005
Posts: 6,999
Likes: 1,685
From: Southeast TX
How much work was done on the heads? Who did it and is it repeatable? I understand the cam specs except for the +2 at the end of the lob sep. angle. What's that? I assume the head gasket is thinner that stock in order to up the compression ratio. Yes/no? Where are the cats mounted? Is the whole exhaust system available as a kit or did you have to piece it together? Don't have a clue what TPIS AFPR is. Showing my ignorance here. Help appreciated.
My (oops her) stock LT1 idles smooth and easy at about 600 rpm. How's the idle on your beast?
My (oops her) stock LT1 idles smooth and easy at about 600 rpm. How's the idle on your beast?