I would like to see, if those who have added boost to their C7, did you have any serious engine or trans problems with your car after it was boosted? Many years ago a friend had a very low mile c7 that had a sc kit added (won’t say brand names), and not long after, the car pushed the front main seal, leaking oil all over the place (due to to much crankcase pressure). Even with the Mighty Mouse catch can on the car it would have some smoke coming out of the can just sitting at idle.

Clearly indicating a blowby issue within the engine. I’ve heard that the piston ring lands are the weak spot with these engines? The car ran fine but it did have excessive blowby.

What has YOUR experience been with a boosted C7 (non z06)?. Clearly a very stressful situation, and it was unexpected from such a low mile car. Obviously, a dead on tune will help this from happening more frequently but that’s not always possible for everyone.

Forgive me if this post has already been created in the past. I’d like to hear your guys opinion and experience. Why do you think that would happen?

If you have had some serious problem after boost, please let others know what the issue was and how much did it cost to fix? After seeing my friends experience with this, I have been extremely paranoid when considering buying any boosted corvette.

 

When the C7 and the LT platform came out it was a pretty common issue for tuners to push the front seal because of crank case issues. The tuning is vastly different from the LS platforms and when you throw a bunch a timing at the LT you better have proper ventilation or the front seal (or piston) will go. Any reputable shop today has gained the experience needed to boost a LT based motor without issue. They love boost.

 

Recently did a lt4 swap on my lt1 myself and has been trouble free for 4k miles so far. 94k on the motor and drive it daily and get on it a good amount. Just make sure your tuner is a reputable one and you should be good. Of course anything is possible when adding additional power but keep it under 600 Whp and it should be plenty reliable.

 

When I did the turbo we tuned it to 550whp. It ran just fine for about a year. I then preceeded to up it to 650 and the ring land didnt like that at all. Put in some drop in pistons and turned it up to 750whp and has been fine ever since.

 

Wasn't because of the boost exactly. Had an injector seal go bad and caused the other 3 cylinders on that bank to go lean.

 

OP - I'm in a very similar situation as you. I'm currently in the market for a C7 and debating between a Z51 to track now and plan to supercharge down the line. Or save up for a Z06 and get the power off the bat.

Coming from a C6 GS, the LS3s handle up to the mid 600s without major fuel pump upgrades, clutch changes, opening the engine, etc.

What's the top reliable number on these LT1s and the drivetrain/fuel system behind it? I read 600whp but that was an older thread and now that here is more info/experience modding these cars, I'm wondering if that number has changed in mid-2024.

 

If I could do it all over again, I'd just buy a C7 ZO6 rather than supercharge a regular C7. My C7 with the P-1X ProCharger makes 576 at the rear wheel (which is about the same as a C7 ZO6). But only makes 522 ft-lbs of torque, whereas the Z makes around 576 ft-lbs of torque at the rear wheel. There are two other disadvantages as well. One is that the cooling system on a stock C7 can't handle the additional heat very well and that's the major problem I'm dealing with right now.

And the other disadvantage is that the torque hits hard on the ZO6 starting around 3000 RPM (which is a lot of fun), whereas on a centri it hits at 4500 RPM (which reduces the area under the curve, as you've already lost 1500 RPM to build up the acceleration with).

 

Well, only seven hours after I made the above post, my C7 engine (with 88,000 miles on it) let go after only 1000 miles with a centrifugal supercharger on it!!!

It was making ticking noises (lifter-tick possibly???) for a few days before it finally let go. I was getting on it when the engine suddenly went to idle RPM and then turned off. Now it makes horrible noises when it is cranked. It is also throwing misfire codes on the cylinders in the left bank. The dealership said there was severe engine damage.

With "only" 576 RWHP, I thought I was safe because I was under the "600 RWHP magic number" for adding boost to an unreinforced LT1. Maybe that guideline has to be reevaluated (or at least with higher-mileage engines).

Dealership #1 quoted me a price of $21,400 to put a Mr. Goodwrench remanufactured LT1 in it (comes with a 3 year/100,000 mile warranty).

Dealership #2 quoted me a price of $14,400 to the same job (also with a Mr. Goodwrench engine).

If I repair it, should I remove the supercharger and just save up for a C7 ZO6?

Or should I repair it with the supercharger left in it (and just cross my fingers)?

 

No issues here but I had the short block built at the same time.

 

OUCH!!! Sorry about your luck man that’s horrible. I’d say it depends on how long you want to keep your car AND how you’re going to drive it. If I was in your shoes I’d buy a used engine off eBay and pay a side mechanic to install it. Save a bunch of money!. I am extremely paranoid to own a boosted C7 unless it’s a Z.

 

Thank you for that! Yeah, the beefed up internals (namely the forged pistons) and the beefed up cooling system of the ZO6 are the way to go!

 

Increasing power with forced induction is safe if you know what you are doing

knowing what you are doing implies knowledge of setting up and tuning practices and you are doing everything yourself

can get the same mileage out of a 2L Nissan 02' sr20det whether its at 200hp or 500hp stock engine, get 250,000 miles
can get the same mileage out of a 3L Toyota 02' 2jz-gte whether its at 300hp or 700hp stock engine get 250,000 miles
can get the same mileage out of a 6L Chevy 02' LQ_ whether its at 400hp or 900hp stock engine get 250,000 miles

Forged internals don't make an engine more reliable or more powerful. Actually the opposite on both accounts.
All forged internal does is allow room to make mistakes, like bad tuning, bad gas, too hot, etc... it can survive
Stock engines are 1 mistake engines, no chance for a single mistake or it will fail. A little too hot and the piston fall apart- its crystalline lattice is brittle fracture failure.
Same as in Nissan Toyota Turbo engines from the factory, which include oil squirts to help control piston temp, something many LS do not have.

Built engines you can make many mistakes, poor tuning and bad setup practice and you don't even know because it just takes the abuse.
Some factory engines are unsuitable for forced induction making a build the only reasonable way out if you plan to keep the factory engine in place. But this is not always a great idea

If you want to learn how to tune vehicles and engines properly you must start with stock engines of all makes and models and push them all until they break to learn from the failures.
Most people want to skip that part (two decades of failures) so they just pay someone to build and tune the engine instead. But it will never be as efficient, economical, long lasting, tight as a stock engine tuned properly.

 

What brand Drop in pistons and rods did you do? Also did you have to machine and balance the crank? Did you add a cam as well. I'm looking to get to 750-800 WHP on my ECS Novi 1500, I already did the LT4 injectors and fuel pump. Not sure if I need a low side pump as well. Thanks for any info.

Tony

 

My build consists of the following. I’m not going to list all the valvetrain parts, bolts, gaskets etc… My numbers are on 12psi and E50 with Meth

D1X Procharger
CP Carrillo pistons and rods
231/242 .6xx 116LSA cam
American Racing 2” headers
RPM low side fuel system
LT4 High side fuel system with flex fuel
RPM custom meth kit
Motion Raceworks catch can

Could be more that I’m forgetting but that is the major portion of it.

 

When you pulled the engine did you have to send out the block for machining and balancing? How many miles did you have before the build? I have 70K miles on my car. Do you think using the current block would be fine or should I do a new short block (LME or Katech).

 

The Rods and Pistons are drop in and rated to 1300HP I believe. They do not require balancing but I only had 6k miles on my car when I had it built. It had 5 oil changes up to that point as well so cylinder walls were perfect. With 70k, I would have it examined by a machine shop. I’m sure they would want to at least hone cylinders etc….