Joepro95

Hello everyone! I am working on my plan for my 04 base c5 and thought I would get the forum opinion from some experienced c5 owners. little background, bough the c5 last May, first v8 pushrod motor experience, previously an import guy, last build was a turbo 370z @523WHP, and was mad fun, but had to sell it when I switched careers and moved. SO after months of research and almost buying a c6 GS, I settled on the c5, am really happy with it, but its time to bring her up to today’s power levels. Being new to the ls platform, I was completely lost when learning about building these motors, heads cams ETC. Still cannot say I know a lot, but enough I feel confident I can start to put together the right combination of parts.

So here are current mods: LG 1-3/4 long tubes, black wing intake and vararam duct, MGW short shifter, LG gt2 coilovers and sways, f14s and c6z06 brakes.
I think it is wise I outline the scope of this project, so here is a list of important factors:

1. Use- I live in southeast OH, driving the Triple Nickle, OH 78, 536 etc, this is a backroad/canyon carver build, I love a handling car, thus why I had a 370z,350z, rx-7 etc, and the vette is no slouch in the corners with the LG suspension, handles quite well.

2. Reliability- I want a solid build and will sacrifice power for reliability, my Turbo Z was a lot of upkeep, and I do not want boost, period, do not say slap an AA or CS kit on it, don’t want it. I drive my cars HARD, it will need to take abuse.

3. Power- With the experience in the Z 500+ WHP was great until a corner, for 425 ish would be my goal for a fun street car.

4. Shops- Wow, this one drive me nuts, almost every time I think found a good shop, someone has some bad experience. This is tough for me, I worked at a dealer with guys that had all built cars, so I did ALL my own wrenching at the shop, the turbo build, clutches, bolt on etc, so paying for labor is like a sin for me, however I do not trust myself inside the ls1, no matter how simple it is, I want it done RIGHT, so I am willing to travel a few hours if I have to, I had to go 5 hours to get my Z tuned, and if that shop did more domestic work, I would take the car there, they do great import work. SO my point of this, starting in Columbus OH( I am in the Pittsburgh area a lot), within a 8ish hour drive, I would like to know who is recommended by EXPERIENCE, and would like a one stop shop for tune, install etc.

SO here is where the fun part comes in, I am torn to just go all in and get everything done at once, or do the drivetrain and or power adders first. My original plan was to do a clutch and gears this year, and cam/heads next year, the more I think, I should just bite the bullet and do it all…

SO if you are still with me(THANK YOU!) here is what I have come up with:


CAM -Either a BTR stage 2 cam kit with springs, rods etc, are dual springs suggested or beehives ok?(seem to be one of the most well liked off the shelf cams LS1/2 Stage II Cam 227/234 .614"/.576" 113+2) or a custom grind from a good shop, I want decent street manners, and good to wind out on curvy backroads and still have some pull on the highway, I know it’s hard to have your cake and eat it too, but hey I’ll see how close I can get!

Heads: only if needed to get close to 425 WHP, was thinking stock 243s would do the trick? I tend to gravitate to OEM parts when I can…

Oil pump: should anything be done? I would like to spin the ls1 at least up to ls6 range, 6500-6700 rpms if possible, is a melling pump needed?

Clutch: thinking mantic single disk or ls7, but I do not like the idea of the added weight with the ls7, (maybe it’s a import thing, but we tried to drop as much rotating mass as possible…)but like the idea of OEM proven part (I know….) I do not think more clutch is need at this level, and there are as many horror stories and positive ones with Mcleods...

Master Cylinder: Show I have a tick installed?

Gears: thinking 3.90s will really wake up the car, but will it induce traction issues with a cam? Maybe back off to 3.73s or just leave it alone? RPM and RKT seem to be the go to for gears.

Trans: From my research the t56 should be ok at this level, unless I do something idiotic, no plans to do anything there…

Well if you made it through all that, THANKS!

Pic for attention!

vettenuts

I have 3.90's and really like them. As for the cam, don't know the specs on that cam so hard to tell. I would definitely replace the oil pump and while in there since you plan a lot of high RPM running make sure to install the timing chain damper, that is what it is designed for because high RPM running and RPM changes can wrap the chain and break it due to some of the harmonics that occur.

Socko

I have a c5z with a 3.42 on z trans the traction is sketchy as hell stock in 2nd. So I wouldn't expect to use that gear in corners with 425 whp unless you plan to go to a lower overall ratio then what my trans is in 2nd with a stock 3.42.

You can buy whole new 3.42's from the dealer which may be viable depending on prices.

If you are already looking that way, call btr in the am and talk to Brian and be really honest. He is very willing to chat and helped me a ton to get the cam i wanted. I ended up with a 227/236 with huc intake lobes and extreme rpm exhaust lobes, i think, huc are about the slowest ramping lobes comp uses i think extreme rpm are the next ones up. Car makes 438 whp on the stock intake, and the curve is very long and flat, so its exactly what we discussed. I really needed solid torque for a couple corners at my local track at 3500 rpm cause you jsut cant apex the corners over 50 and like i say, 2nd is a disaster waiting to happen. He can get you what you need as long as you really understand what you want.

Heads, i sent mine to TEA and they were excellent, I am a hard person to please and they were very responsive to my 6-7 phone calls and probably 15 emails during the process to get everything sorted out. I kept stock valves and decked them .06(yeah thats a good bit) and had btr ship springs to them guys which they installed. Cleaned up my stock hollow valves as i wanted to keep them so i could spin the motor a bit.

I did all this after i had my whole trans built with steel 3-4 fork and all billet syncro keys. and did the clutch and new master and slave. Also already had a stock new diff in the car.

Best chance to get it done right is to do it yourself. Assuming of course you have the tools and skill set to do a good job. No one is going to care as much about building your car right as you are. Ls motors are silly easy, there are a few tricky parts I guess but they are easy cause all the info is on here or ls1tech. Just dont be lazy about it, "IF IN DOUBT, TAKE IT OUT". In the long run the car is incredibly easy to work on, as long as you get all teh crap out of the way. its never worth struggling with the radiator or rack or bumper or whatever. Just take stuff out of the way and save yourself busted knuckles and time. Hell i pulled the whole trans myself last year in 3 hours, and I'm really slow at doing car work. It is so easy to work on at this point that I am pulling the rear out this year just to inspect guibos and bearings in the torque tube that are a couple seasons old.

Joepro95

Thanks for the input guys! I updated the original post with cam specs. The m6 base had 3.42s but the c5z had shorter Trans ratios from my research which would equate I think around 3.73 to 3.90ish....I was assuming good rubber could hold the power... But if it's an issue maybe I'll just go start with cam/heads and clutch, diff is relatively easy to do but with it all coming out figured it made sense if I was going to change them. Unfortunately in my new career I do not have access to a lift and tools as I once did or I would definitely do it myself and learn.... But this time I will have to rely on a shop to do it most likely.

Z06copley

I have to echo Socko on traction, I have a c5z with only minor upgrades (halltech intake and bassani exhaust). I too left a nissan z for the vette and found it to be completely different IMO. Personally, I went with larger tires almost out the gate (335/30-19). still gets squirelly when playing around too aggressively, but anywhere near as bad as the factory size. Everything else sounds awesome and the car looks great!

Joepro95

Thanks for the input... I think I'll start with the cam/heads clutch and see how it goes with the stock gears for now.

ZZ06

Sounds like your wrapping your head around the LSX world well. Be careful, the mod bug bites hard in these cars. Cam and heads will probably net you over what your looking for depending on how wild of a cam you desire. I guess one could always pull timing. Leave the gears alone for now and just see how much you will enjoy the new power. I have an 01ZO6 so my gearing is a little shorter than yours but nonetheless, the car will feel like a rocket after those mods. If your considering much lift over .600 id go dual springs for the added security.

Joepro95

Thats why I was thinking just a stock set of 243s will do the trick, essentially turning it into a cam ls6 witch I have seen in the low 400s for HP.

ZZ06