00Vette04GTO

Hey guys,

So it has been a hell of a learning experience, but I am finally getting somewhere on my vette build.

Due to the bad decision to buy an ebay motor I fought with one swap for months.

So I started a-new... With some of the parts I have acquire, and some new.

C5 A4

LQ4 6.0 Block with rebuilt bottom end
trickflow generation X
FAST AS CAST 220 cylinder heads for LS2
205.5 intake valve
1.570 exhaust valve
65cc chamber volume (milled down to 62cc)
Compression: 10.5 : 1
LS6 intake
42# injectors
3000 stall converter
BBK short tubes
off straight pipies, no cats or mufflers, out the back
cam - 588 lift 224 228 114
Comp 1.72 roller rockers
Lunati Lifters
Vengeance Tuning

I got this on the dyno at Vengeance Racing:
(first run without TC locked, second with)



Couple of questions:
1: Do you think I flat lined like that at the end due to lack of cam, air, or the Comp roller Rockers?

2. I put expensive Lunati lifters in to avoid the ticking problems people have with GM lifters. Well... Since first start one lifter ticks (99% sure a lifter). Should I just go with LS7 lifters or buy a replacement for this Lifters? (I like their design but expensive if they fail easy)

3. While fixing the lifters should I up cam? I have this laying around:
226 229 dur@ .050 .576 .578 lift 112 ls.

Or get a hotter one? They are pretty cheap? Still want a daily driver, but more is always better and with my stall it doesn't lock until 2800 RPM anyway.


FYI: The vette runs great. Spins the tires a little at 50mph when I floor it (with traction control on)... That's always neat.

Thanks for all the previous help and any new thoughts!

-Mike

Soulefood

since the heads are milled did you check the PTV clearance when you installed the cams? with the milled heads and the aftermarket rockers the "ticking" could be PTV contact? the lunati lifters should be fine although if you feel the need to try other ones try the comp cams short travel race lifters. i use them and have heard great results with them.

00Vette04GTO

Yea... Have plenty of PTV clearance.

It definitely sounds like just 1 lifter. Checked rocker arms and push rods with no bad wear on them. Next, just need to pull the heads... Ahh the joys of having cars as hobbies.

04tripleblkcoupe

Well with your setup thought u might of had a little more on HP. My 04 A4 LS 1 head and cam package from Vengeance my dyno #s were 438 hp 402 tq with long tubes 3in full exhaust 3200 stall and that was with a stock bottom. and 273 gear. Comp cam 236 238 601 605 and trick flow 220 as cast heads

95wht6spd

Get some headers, and a bigger cam matched to the head specs.
It should make more power. My LT1 h/c made 403whp 6 spd.

00Vette04GTO

I have the 3.45 gear... Though I would have thought I'd make more power too, but Like 95wht6spd said I think I need a bigger cam... Wondering how big I should go... Longtubes wouldnt hurt either. Also everyone told me those comp rollers could float valves. Ive since gone back to stock - I wonder if that made any difference...

But one advantage that the 6 speed guys have is they loose Waaay less to the wheels. Us A4 guys are somewhere from 18-20% as far as I understand.

NukeC5

The shorty headers are killing your torque. Definitely do some long tubes. I'd go with a 3600-3800 stall converter. Still decent on the street, but at that stall you start getting into way better torque multiplication. I have a 3200 with similar cam specs and the converter sucks at the strip, I need higher stall.

Soulefood

I have never used the comp cams roller rockers, always used harland sharps but whoever told you the comp rollers would float valves passed some bad info. floating valves are a result from insufficient support at high lift/high rpm situations. this occurs when you don't have a stiff enough spring. The only thing thats truly different besides the roller fulcrum on the end and reduced friction, is the rigidity from the stiffer body of the rocker. The stock rocker body is a stout design however it still flexes at high rpm/high lift situations so you might not get the true lift potential from your cam. of course we are talking very small increments possibly not notable, but still present. I would go back to a roller fulcrum and if you think your floating the valves, opt for a stiffer spring.