C5Navy

I have a 2000 c5 that just hit 90k miles. It's my daily and it makes 409/377 with a 224r cam, pushrods, valvesprings, slp oil pump, ls2 TB, fast 102 IM, CAI, LT+xpipe(no cats), straight pipes, msd wires, ngk plugs. I'm looking for opinions on what my next best bang for the buck upgrade would be. I would eventually like to boost my car but I'm worried it might not be safe with the amount of miles I have on it(?) What are some things I should be worried about as far as overall engine health as I approach 100k miles? The car runs great overall except for some slight idling issues. My car was tuned by Cunningham Motorsports in Murrieta, CA. Thanks for reading!

neutron82

I wouldn't worry about boosting it with your mileage, there's plenty of guys with quite a bit more miles than that doing just fine... you got the oil pump taken care of, the only other concern I would have is maybe the lifters... take the fast102 off, sell it, and get a stock ls6 intake if you do decide to boost it... the fast is structurally weaker than the factory intake and notorious for cracking and leaking under boost and the power difference most likely won't even be noticed unless you are doing a max effort build... you will probably need a clutch and possibly some other driveline upgrades... if you aren't careful it can get crazy really quick, my advice would be to set a reasonable goal for yourself and build for that goal instead of going in it blind and throwing part after part at it

ezrider4u2

with neutron82.

With your mileage, if you are thinking about boost maybe also consider the state of the clutch if its an MN6, tranny and rear end may need some TLC. More power bring more stress to the driveline. Also should consider that the torque tube may need some attention as well.
Check what we found during my SC project https://www.corvetteforum.com/forums...m-changed.html

beamg5

Maybe it's just my own "paranoia," but I, personally, would feel a whole lot more comfortable about boosting an engine with 100K miles on it if it were "freshened," up particularly with a few key forged internal pieces/parts before proceeding.

I am, admittedly, very careful about serious engine mods !!

Gary

C5Navy

Yeah I originally wanted to go for a NA build but I feel like for what I'm getting on gains, I'm spending way too much. I've also learned the hard way that sometimes the "best" parts are not always the best parts if you know what I mean. Nick Williams 102 was terrible for tuning and the fast 102 is INSANELY overpriced especially compared to the Ls6. Thank you for your input though. Very helpful information. But will the fast fuel rails and ls2 tb fit a Ls6 intake mani? (Sorry.. I'm such a rookie haha)

ezrider4u2

very true. Next thing you know a simple project is now $10k+

C5Navy

My car already has a stage 5 rpm tranny and an Exedy Clutch

alxltd1

Did not see it in the above, but are you still running the stock 2000 853/241 heads aside from upgraded valve springs?

C5Navy

Yes stock ls1 heads

alxltd1

Then if running boost is a concern, or down the road a while, given you are running the FAST intake and 90mm LS2 TB, I would go with upgraded heads to maximize the intake, TB, headers and cam. Even a set of 243/799 heads would increase flow and compliment the other mods already on your car. Just don't go to high of a compression ration if you do want to boost it later.

SaberD

Do you have any differential upgrades? I'd definitely start there. Upgraded clutches, belleville washers, and output shafts.

Add a diff/trans brace.

I'd also go with an 01+ torque tube with upgraded couplers.

Also do urethane engine and trans mounts. The stock ones let the engine and drivetrain flop around like a fish out of water.

Add a timing chain dampener and upgrade the timing chain.

Also upgrade the harmonic balancer. The stock one likes to separate - causes vibrations and sometimes carnage.

I would also suggest upgrading to the LS6 PCV system.

Also perform the rocker trunion upgrade. The stock rockers are already a weak design, and when you start adding stiffer springs and a bigger cam, it really puts a lot more stress on the rockers.

If you can afford taking the engine out or dropping the front cradle and oil pan, I'd upgrade the rod bolts to the katech rod bolts. RPM is going to be a limiting factor with the stock rod bolts, and I would not suggest spinning the engine past 6250 with the stock ls1 rod bolts.

Reliability first and then add power will save you time and money in the long run. It seems like a lot, but you have to realize the car was not designed to handle this much power. You have to pay to play if you don't want things to break.

The 853 heads are going to be the real bottle neck here. Ported 243 heads would help a lot especially with the sodium filled valves for FI applications.

Definitely upgrade to LS7 lifters and LS2 lifter trays when the heads are off.

My $0.02

enoniam

I agree with the lifters. I had one go out in my vette this year at the end of the hot rod power tour. Cost me close to $1500 to get the car able to limp home (lifter replaced at Chevy dealer), $900 for machine shop (bore out lifter bore and press in sleeve, polish crank journals, hone cylinders, hot tank block, install cam bearings and freeze plugs) and over $1500 in parts that I installed myself, the single most expensive being a new cam. Put new LS7 lifters this build. When I disassembled the engine I found the cam's Comp part number on it which indicated it had XE-R lobes, which aren't known for being gentle on the valve train and I suspect may have contributed to the lifter failure. The new cam has gentler XE lobes but more duration.

As far as the mileage and being able to take boost I don't think that is really an issue for you. I put a supercharger on my LS1-based truck's 5.3 engine with over 200K on it and retired it this year with 289K due to a slight but persistent #7 cylinder miss that I couldn't get to go away by changing plugs, wires, coils, or injectors. That engine saw up to 11 pounds of boost up to the end. GM rates the stock hypereutectic pistons as good for up to about 550 hp - their highest hp crate engine that uses them they list at 556 hp. I suspect I was getting a lot more out of that engine which may be why I was having a miss. If you are going to tear into the engine and plan on being at or over 600 crank hp you should upgrade to forged pistons.

As far as rod bolts, stock ones should be good unless you want to tickle 7000 rpm. I had that truck up to over 6800 on the dyno last summer - it probably had over 275K miles on its original rod bolts at that time. (I'm the truck's original owner.) I put LS2 rod bolts (as well as new LS2 timing chain) on the vette's motor and have had it bounce off the rev limiter set at 7050 rpm. (Per Comp new cam's power range is 2200-7000 - she loves to rev!)

Please let me know if you want to sell your Fast intake manifold, or do a trade plus some of my cash for my polished Weiand/Lingenfelter intake manifold! Per the below link, it performs better than the LS6 - but not as well as the Fast.

http://www.hotrod.com/features/1507-...ifolds-tested/