KrisR

iTrader: (2)

I just bought a lightly modded 2000 C5. I was thinking about switching to some better heads over the winter, if it would even be worth it on my setup. Car has a stock LS1 bottom end, PRC stage 2.5 ported 5.3 heads, Texas Speed 228R cam (228/228, .588/.588, 112LSA) which I would like to keep using because it drives so nice. LS6 intake. Longtubes, no cats.

I might go with a FAST 90 intake and TB if my setup would benefit from it.

Are there some heads out there that are really worth the swap over what I have with stock cubes? AFRs / Trickflows I'm guessing?

Honestly if I can't pick up maybe 25rwhp it's not worth it to me.

The car currently has a modded stock airbox and stock airbridge, and with an E85 tune with 11.8 air fuel (E85 is actually E70 around here now so it's pretty rich) it made right at 400rwhp SAE on a Dynojet, which seems a little low.

Sales1@Texas-speed

Depends on your budget, but our CNC ported 2.5 LS6 cylinder heads show gains of in excess of 35rwhp on a regular basis. Feel free to give me a call I would be happy to go over some options with you.

KrisR

iTrader: (2)

Gains over what? Stock LS6 heads or LS1 heads?

Sales1@Texas-speed

Sorry I misread the first post. You already have our 2.5 5.3s. Since your in that situation your best bet would for sure be an aftermarket casting. My recommendation would be our PRC 227 cylinder heads, but honestly I dont see you picking up 25rwhp no matter what cylinder head you put on this motor over what you have now. If it were a larger bore then we could probably be able to achieve that with one of our other castings but not sure about this application.

Sales1@Texas-speed

Also would definitely benefit you to ditch the stock airbox and bridge, along with swapping to a Fast intake setup.

KrisR

iTrader: (2)

Thanks for the info. Does ~400whp SAE sound about right for my setup with stock airbox/bridge and less-than-ideal tune? It does have an underdrive pulley also.

Any guess as to how much I would pick up with an aftermarket inlet setup, and also the FAST intake/TB?

My old C5 Z06 made 414rwhp with stock LS6 heads/intake and a 226/226 cam, longtubes, but with a Halltech intake setup, so I'm kinda comparing that car to this one.

Sales1@Texas-speed

Yes it definitely seems to be down on power, but as we all know there is a ton of variables involved when dynoing cars or various dynos. I would expect a solid 25+ rwhp with just the Fast intake, and cold air intake swap pretty easy.

LS1T56FTW

iTrader: (3)

It's all in the tune man. With an almost identical setup (I have a lid and stuff though) I put down 470whp and my full weight Camaro traps ~122 with an OK launch. With a FAST I am hoping to be around a 125 trap with a good launch. I would just push that setup you have now to the max. Dyno numbers mean very little. I have walked a few cars with bigger cams/"better heads", even on the top end, such as here:

http://www.youtube.com/watch?v=7I_lm...ature=youtu.be

(I am the first race, video was cut way short but that car has P/P LS6 heads and a 24x/24x cam).

01ssreda4

iTrader: (96)

Sounds like you need a tune first, then maybe fast 92 or 102, and maybe some gears. Those 3 should wake the car up big time.

SSTYCOON

iTrader: (2)

You'd think the LS6 intake would be fine on this stock cubed set up.

kinglt-1

iTrader: (26)

Yes it will be fine but your leaving power on the table.

KrisR

iTrader: (2)

I'd like to get an idea about how much. If it's something like 10-15rwhp, it's not worth $1000+ to me for an intake and throttle body. If it makes another 25hp, then I'd probably find one and bolt it on.

Trouble for me is, the car I just sold was a 680rwhp built 99 Mustang with a 76mm turbo. An extra 50rwhp was just a turn of the boost **** away. I got a little spoiled I guess.

kinglt-1

iTrader: (26)

Aaron@ texas speed previously posted you would pick up 25whp with the fast intake...imo your going to see better gains per dollar with the intake over switching heads in this situation.

KrisR

iTrader: (2)

The 25hp was with the FAST intake and a switch to a good cold-air setup, but thanks.

TT427

iTrader: (1)

Wondering what you have for exhaust, if you have room to grow their, coupled with an intake and tune... Could see a huge gain, would help that weaker exhaust port and cam combo. Sorry didnt see the LT/no cats...

KrisR

iTrader: (2)

Yeah, it has longtubes and no cats, and some kind of aftermarket exhaust, unknown brand, but it's pretty quiet.

TT427

iTrader: (1)

I realize you want the drive ability of the cam, just a suggestion, maybe fill a few forms out from the vendors and ask about your specific combination coupled with a full inlet swap. Sell what you have and you will be not much further in the hole. From what I gather that is an all around great shelf cam but maybe not what your parts need... If its not tuned perfect yet and its still a great driver, maybe those heads and the compression, coupled with your exhaust will tolerate something a little bigger/broader? Plus being a vette maybe a little lighter weight helps.

dannyz

Just throwing this out there, even a small shot of nitrous would give you WAY more the the rwhp your looking for, at just a fraction of the cost.

mkvamso

iTrader: (2)

The combo you have now should easily make 430, ive seen a c5 with the exact same setup except with a blackwing make close to 450, id start with some kind of cold air, and get it retuned. your leaving a bunch on the table right now with your current set-up.