Hello all, I am going to be purchasing my first C5 in the upcoming weeks after owning 3 different C4 corvettes(84, 92 FBO heads and cam, and a procharged 89) and I have gotten tons of incredible advice on this forum so I am looking for some input on any small quirks I should look out for, I do know of the EBCM issues on earlier years, I am aware of the Harmonic Balancer issue, AC actuators and the lifter issue these LS engines are prone to,these aren't of much concern to me as I am fairly mechanically inclined but I am looking for more specifics on what to look out for when you start to push more power. I am torn between an auto or a manual trans. I am aware that the 4l60E can not handle much power besides what is stock at all and a built one is looking like it is going to be a couple grand and a couple grand extra for installing at a shop ( I did the clutch job on my 92 and it is not feasible to do it where I am currently living so large jobs like a clutch need to be done at a shop) I will be doing exhaust and a heads/cam on this car and I am looking for about 400 wheel, will the Manual trans hold up to this and will the diff be fine? On that same note approximately how many hours would a Clutch job cost on a manual car?

Also just any other issues in general would be appreciated, looking forward to getting in a newer corvette as I have been wanting to build something on the LS platform for awhile.

 

The basic C5 performs well with the 350hp it was designed for. Empty your wallet with aftermarket bolt on mods and you'll have a money pit. More power, drive train problems, transmissions, clutches, cooling, brakes, torque tubes and more not to mention the smog inspections in your state. Need more HP? I suggest you buy a C7 or something designed to handle big HP. Just sayin after owning nine Corvettes. Good Luck!

Watch a video to do a clutch or transmission job on a C5. Bring your credit card to the shop!

 

That is a wide open question due to the many variables.

Things like what was done, how well it was done, the quality of the parts used, the combination and compatibility of the parts used, how it was driven or abused, how it was serviced, how well it was installed.

When it comes to mods these things are all very important. Many will say buy a stock car as it is the safest thing to do. This is true. But there are good modified cars out there but you need to look for the ones that are well documented. This helps take the guess work out as you know what was out in and if it all works well together. Receipts, Dyno test. Tuner paperwork, things like this give a better picture of whst us going on.

Too often some mod projects are people that are dumping a car because they got in over their head and it is up to you to sort out.

I work in the performance aftermarket and get many calls trying to find what parts were put in a car someone bought and is having trouble with.

How much power can affect drive line. Things like trans missions clutch couplers etc. installing headers. Did they do it tight and not burn up wires?

The C5 as a whole can take decent power updates but most are drive line upgrades. Normally 100-150 hp is not an issue. But also how you use it matters. Slick? Lots of track time? How hard was it driven?

Other things like coolers snd better radiators are a factor more HP adds heat. Many will spend $q5k on an engine but put the stock radiator back in to save $600.

Just hints to consider. Mod issues are judt more wide spread vs stock.

 

He means plural CC.

 

Well you know for sure 405 HP works based on the Z06. We see supercharged cars to 450 HP with little issues. If you don’t abuse it harsh 500 can be done in most cases but this is where use and Hp can make that last 50 hp tricky.

the C6 is not a lot different. The C7 in the big hp cars used a lot of computer aids to make it live.

The one point you made is you have no place to work on it. In many modified models you will have an issue or two along the way no matter what you do. If you have no place to do work then I would just opt for a C6 or other higher stock HP car for now. Even then you risk issue as these are older cars that still can have an issue. Mine is stock but I lost a Cat pipe. No big deal I could fix it here at home. But lack that space that could be nearly $2K with parts and labor.

Best to go in expecting the worst and being ready for it and then never having it happen. That way if it does then you have the budget and place to fix it vs another Corvette with stuff piled on it in a garage some place.

 

400 to the wheel is very doable with a manual car. I have a 410 wheel 2000 with a manual, it does just fine, LS7 clutch holds it no issue. My personal feeling is that a manual is the only way to go in these cars, but that is all preference. A clutch job with torque tube rebuild will run you $3-3.5K at a shop.

 

"Common issues when modified...?" The simple answer is more mods.

The C5 is a great platform and responds well to mods. Power comes easily too so your goal at the wheels is readily attainable.

The transmission choice to me seems simple. I DO appreciate automatics, but I am tainted by the newer 6, 8 and 10 speed varieties. Not only do they provide power on tap in multiple demand conditions but they are stronger products while the 4L60E is hard, and expensive, to trust. The T56 manual is the best choice all day as long as your back and left knee are still good. Not to mention the car is a lot more fun with a stick.

 

I paid $2200 for a clutch, bleeder, clutch master. About half the amount is just r&r for the drivetrain, and I supplied the GM LS7 clutch/flywheel/pressure plate kit.

Earlier this year I added Z06 heads, cam/springs and tune. Cam is midrange, mild by many standards. Running through stock manifolds and cats, 366hp/370tq at the wheel. Only side effect is slightly more lifter noise. 3000 to 5000+ is seemingly instant. I designed this build with the idea of Z06+ level power for fun rips, but in a safe range. Bigger cams need more spring maintenance, which is fine if you’re willing to do it. But the higher your rpm, the less longevity in the bearings/valvetrain/pistons. For example, a 7500 rpm engine will live about half as long as a 6500 rpm engine. So plug these things into your build goals.

The key to not hurting components is don’t test their capabilities. It gets expensive to find that limit. I do not drop the clutch from a stop, instead rolling starts. I granny shift. I don’t hold high rpm’s for extended periods.

 

Seriously? he's talking about 400 rwhp. Many on this forum (me included -- 530 hp at the wheels) are at 500+ rwph with zero issues. Other than a z06 clutch and routine maintenance, my transmission is otherwise stock (I did put in 4.11 gears in the diff and upgraded the internals, but many people don't, and that was certainly not a money pit).

But -- it does *highly* depend on how you're going to use the car. I track my car once in a while, I don't drag it, and mostly use it for pleasure cruising. If I was going for a serious track car then I would have spent a ton more $$ on it (but that really goes for any car, not just the c5).

To the OP-- you can easily hit 400 at the wheels with heads/cam/exhaust/tune... even easier (and more hp) if you drop in a super charger as many on this forum have. On transmissions, the manual can handle the power with no problem. Clutch on a c5 is a pain to change (I have a lift and have the ability to do it, but still had my mechanic handle it), as has been said, and highly suggest dropping in a z06 clutch. I don't know enough about the auto to weigh in on it, but if you're going for a fun car, then go all the way and get the 6 speed!

 

Depends on how you use the car, you can have 500 at the wheels, race the car and stuff will fail or you can have 500 at the wheels, only do dyno days & car shows and the car will live forever.
My car at 550whp broke the output shaft and differential but I dig race. 400whp is simple to do, ported 243 heads, small cam, exhaust and a tune

C7 handles big power no better or worse than a C5

 

This is what we’re talking about! 400 wheel is roughly 450 crank. That’s a stout driver 👍👍👍

 

Thank you all for the advice (except for telling me to buy a c7 lol)

I’ve been leaning towards a manual and I’m pretty sure that’s the route I am going to be going since I have been seeing many people say that the manual driveline will be fine for a heads/can build.. I don’t mind having to pay the labor for a clutch job to be done right especially since this is going to be more of a fun weekend car that will be tracked very minimally.

Although I don’t have the space for large jobs such as a clutch where the car will be down for multiple days I do have the ability to do most repairs and work and I also have a tuner who is 10 minutes away from me so these are all considerations when it comes to building one of these.