C5 build questions
 

Ok new to forum, I bought a 98 c5 low miles. I’ve bought headers, 3hp starter, gaskets, springs, 228r cam, going to port and polish heads, already have full exhaust n x pipe, new timing chain. Things I’m purchasing next ls7 clutch kit is that a good decision? High volume oil pump, 7.4 pushrods, headstuds, an I need to get a tuner?? Ok so open for suggestions and thoughts. Before I take it apart and install everything. Thank you

Good luck, I dont have a clue
Bill

Is your current clutch slipping at your power level?

If you do the clutch, there are a bunch of "while I'm in there I might as well do.........."
Remote clutch bleeder
Inspect torque tupe bearings and couplers
Inspect halfshaft seals
Check ball joints
Replace rubber bushings with polyurethane
Replace slave cylinder and pilot bearing
Switch to Castrol SRF fluid
Thicker tunnel plate
Wrap all the lines with heat insulated tape
New O2 sensors
Polyurathane transmission mount
Those are some suggestions for when you just changing out your clutch.
Do a thorough search and you will find an endless mine of "what should I do next" topics.
Let the sickness begin.
Spaggsl

Since you have a '98, tuning it yourself will not be easy. HPTuners and EFILive will only work with '99+ PCMs. And you will want to tune it after all of those mods.

No clutch is solid no issues. I’m just worried about adding power and it not being able to handle it!?!?

Welcome to the asylum...:willy:

From what I can tell, your mods are basically cam/heads/exhaust - is that correct? If so, then unless you plan on drag racing with slicks or drag radials, your stock clutch should hold up fine IMO. Keep us posted on your build! :cheers:

ok sounds good this will save me time and money. Appreciate it, yes I’ll post when I start the work in a couple weeks.

im not going to tune it myself, I need to find a shop near Jacksonville, Florida. What tuner will work with a 98?

If it were me, I would not spend time/money on stock heads. Find some 243's, do the trunion and spring upgrade.

As far as tuning, you should really consider finding a good dyno tuner in your area and discuss with them your goals with the car and how much HP you want to squeeze out of your combo vs. safety / reliability of the tune. They will get everything exact and perfect with fuel curves, timing, etc.

Another thing I would definitely replace is your valve springs and maybe consider rocker arms as well.

yes I did 160 lbs valve springs and titanium rockers.

with 243 heads, I’ll need new valve covers, is there anything else I’d need?

Unless you're pulling the engine or the drivetrain, don't bother upgrading a clutch until you know you need to. May well be a waste of money.

You're also likely to be happy with the LS6 clutch. As long as it holds, which for an NA build is highly likely, it's lighter than the LS7 clutch.

got it, so I most like will pull the motor, so my plan is to check out the clutch n if it is good leave it alone.

If you're pulling the motor, it may make sense to go for a clutch. Depends. My guess is that with the cam and ported-polished heads the stock LS1 clutch will hold, but upgrading to an LS6 setup may make sense. While you're in there, new pilot bushing, new throw-out bearing, new slave cylinder, obviously -- but also don't forget the rubber prop shaft couplers and the prop shaft bearings (often called the torque tube couplers and bearings, also guibos I think.) At minimum, those rubber couplers may be hard and crappy simply from age if not miles; if the rest is fine, new OEM couplers may still be a good idea.

Also probably a reasonable time for a shifter swap if you want to do one.

Mounts are not available OEM. They, too, may be a bit meh due to age, but I bet they're still fine.

Other than that ... depending on the power level you eventually want, and how you drive, it's a hell of a lot easier to install stuff like a trans/diff brace with the driveline dropped down.

awesome ok, I’ll look into ls6 clutch, thank you for all the info

personally I wouldn't even consider a stock clutch if you plan to race the car, spend a little more and get something that won't give you shifting problems... my c5z clutch wouldn't shift right at wot when the car was stock, the more power you add the worse it gets... it will technically hold the power fine but the issue is when you shift, now if all of your racing consists of single gear pulls then you would probably be ok lol

I put an LS7 clutch in my C5 and to be perfectly honest I didn't like it. If you do go that route definitely investigate putting a spacer behind the slave cylinder because that installed height is different.

I now have a car with an LS7 and obviously an LS7 clutch, and I'm not thrilled with it in this car either. If it were me, I would do a twin disc knowing what I know now. The odds are, you're probably not going to get to a power level that the clutch will be an issue, but if you put a twin disc in it certainly won't. It'll be a hell of a lot nicer to drive too.

Will, lets go back to the start.
What are you using the car for, racing or spirited street driving?
Do you have any info from the previous owner on any parts that were changed/upgraded?
Just so you know you do not have to pull the engine to change cam & heads.