New c3 owner performance questions
#2
I bought a C3 and this is my first entry into the Corvette world. Unfortunately I have one of the L-82 engines tuned down for emissions reasons and I'm not fully satisfied with the power. It came with a weiand 142 which is also the first forced induction engine I've ever owned. The previous owner didn't really know much about it and told me to the best of his knowledge everything is stock. I honestly wouldn't be able to tell the difference in stock and aftermarket so I come to you for help. from what I've read a good free-flowing exhaust/headers is good for around 25 hp. but with my "stock" bottom End will I be able to handle that along with the supercharger at five psi without throwing a rod. I also looked into Vortech heads but I don't want to raise the compression ratio with the blower on there. can anyone point me in the right direction budget being roughly 3000
Last edited by rickiedh; 08-11-2017 at 03:45 PM.
#4
Le Mans Master
My thoughts,
Headers with a nice exhaust are worth it. You are just freeing up a restriction that will allow the spent exhaust to get out of the combustion chamber better with allows for a cleaner intake charge.
Also in the picture of the exhaust the bracket above looks pretty bad. Did you go over the frame and bird cage for rust?
Without knowing how the internals are built check your timing and make sure you don't get any detonation. I always use Menthol injection on my Supercharger builds.
Headers with a nice exhaust are worth it. You are just freeing up a restriction that will allow the spent exhaust to get out of the combustion chamber better with allows for a cleaner intake charge.
Also in the picture of the exhaust the bracket above looks pretty bad. Did you go over the frame and bird cage for rust?
Without knowing how the internals are built check your timing and make sure you don't get any detonation. I always use Menthol injection on my Supercharger builds.
#5
Drifting
Member Since: Oct 2005
Location: Forth Worth TX
Posts: 1,615
Likes: 0
Received 148 Likes
on
136 Posts
Can you return it?
Quite honestly, it looks like you've made a mistake. I don't see how spending more money on it will make it any better.
You should have posted here before buying it.
Quite honestly, it looks like you've made a mistake. I don't see how spending more money on it will make it any better.
You should have posted here before buying it.
Last edited by Revi; 08-11-2017 at 09:18 PM.
#6
Drifting
A blower on a stock motor? Sounds like the previous owner had more money than brains and just wanted something that looked cool. I could MAYBE guess its a sleeper, but that stock exhaust is a dead give away. Judging by the pristine condition of the supercharger and the nasty condition of your bottom side, Im sure the previous owner just wanted to show boat. As others have stated, start with a set of headers. If you go past that...just go full tilt and add a cam and heads. You can do that for under 3K if you do the work yourself. Dont get discouraged. You have the makings for a very stout engine there.
#8
Instructor
Yeah why not? Have you gone through the ignition and fuel system to get it tuned right and up to snuff? A bigger exhaust will really help-though you might have to fiddle with the fueling a bit with the addition of a free flow exhaust.
Water meth injection seems like a good idea and also ought to allow you to push the tune for more power while adding some insurance against detonation.
Cooling system too-get a 190 thermostat in there. Looks like some of the foam seals for the rad might be missing.
Someone spent some money on this thing at one time-I think that sort of period speed equipment is cool. Clear up the deferred maintenance issues and always check the age of the tires-lots look good and are very old.
You might also look into the rear gearing and see what you have
Water meth injection seems like a good idea and also ought to allow you to push the tune for more power while adding some insurance against detonation.
Cooling system too-get a 190 thermostat in there. Looks like some of the foam seals for the rad might be missing.
Someone spent some money on this thing at one time-I think that sort of period speed equipment is cool. Clear up the deferred maintenance issues and always check the age of the tires-lots look good and are very old.
You might also look into the rear gearing and see what you have
Last edited by Sunracer; 08-11-2017 at 10:38 PM.
#9
Instructor
Here's something else to look at
http://documents.holley.com/199r10244-1.pdf
Manual for install of your system.
http://documents.holley.com/199r10244-1.pdf
Manual for install of your system.
#10
Drifting
If youre not familiar with a supercharged setup, might be best to take it to someone that knows what they are doing or remove it. A lean condition or wrong timing under boost could blow a hole in the pistons, bend a rod or throw it through the block.
#11
I gave 5500 for it, you can tell me if I got hurt or not. But I really wanted a 4 speed and a black paint job,this was it. Also I checked the bird cage as best I could on site and while it's not perfect by any means it wasn't flaking and full of holes
Last edited by rickiedh; 08-12-2017 at 03:15 AM.
#12
Asumining the frame checks out ok, you may want to look at the bushes and any other rubber part as well.
#13
Pro
Member Since: Apr 2014
Location: Orlando, Dundee, Val-des-Monts PQ
Posts: 610
Received 182 Likes
on
124 Posts
Rick, Don't let the "Debbie downers" discourage you. I think you did ok. As you said it's black, 4 speed, 2 door sports car with t-tops. I would not put much more money in the motor, save up and get a crate motor and put the goodies on the new motor. You don't have to roast the tires to look cool. Mark
#15
How does it run? $5K is cheap. If it runs good, drive it till the wheels fall off then fix it.
#16
Drifting
Ignore the nay sayers.. you bought it, so obviously you liked something about it....$5K is cheap...besides The L-82 bottom end is 4 bolt and Forged , basically a later version of an early LT1 ,with less compression.. which is good for boost.. 5psi boost is not extreme.. your bottom end should hold just fine. .. ENJOY
#17
Race Director
Member Since: Apr 2016
Location: Pittsburgh
Posts: 10,683
Received 4,713 Likes
on
2,998 Posts
2023 C6 of the Year Finalist - Unmodified
2022 C6 of the Year Finalist - Unmodified
2021 C6 of the Year Finalist - Unmodified
From the pics that you posted, the usual suspects appear.... the car needs new exhaust, shocks, bushings, suspension parts in general, all of these items can be replaced at a cost. The frame & birdcage? A L82 with a blower on it & the hood cut open.
I would drive the car as is seeing that you don't have a lot of $$$ in it, if you want to go further, this car will require lots of cash to improve
I would drive the car as is seeing that you don't have a lot of $$$ in it, if you want to go further, this car will require lots of cash to improve
#18
Le Mans Master
Im with fishslayer it's a great bottom end. You need headers and 2 1/2 in exhaust and get it tuned. It will scream. Good luck I think you did fine!
#19
Racer
I think you got a great deal on it! If the engine was in good shape to start with 5 psi should be nothing for it. Like someone mentioned L82s had forged internals and would be a solid foundation for what your doing. I would do a leak down and compression test on the engine to see what condition its in and go from there. If you had to and given the choice I would rebuild the original engine rather than buy a crate engine. A good custom engine builder will always supply a better product. I would open up the exhaust like you planning and take it from there. Anyway looks like a cool car that`ll be a lot of fun!
#20
Melting Slicks
You got that for $5K? You did great. Enjoy it. Don't expect it to be reliable, and expect to spend money on it. You can also expect to have fun with it. Congratulations.
FWIW it looks better than my car did when I started. Start with the safety stuff - suspension, brakes, tires. Make sure the frame is sound. Go from there.
FWIW it looks better than my car did when I started. Start with the safety stuff - suspension, brakes, tires. Make sure the frame is sound. Go from there.
The following users liked this post:
Khibbs (08-18-2017)