mchicia1

Swapped out the 231/239 to an Ed Curtis custom 219/231 and gained .2 and 1.5 mph in the 1/4 with a bonus of 3 mph in the 1/8th. Same DA and same awesome 60 foot. WTB someone who can drive my car better than me lol. I shift well, but I can't figure out how to launch. I was on beat drag radials, so maybe that's why.

Setup is
'99 FRC
Forged 347 - lower comp than stock (always dynoed 20 rwhp less than it should have)
As cast ls3 heads (small bore style)
LS3 intake - LS2 TB - Vararam
LS7 exhaust manifolds with cats to a 3" catback
LS7 clutch
stock 3.42 gears

So yeah, pretty much all GM factory parts minus cam, vararam, and catback. It's a weird setup, but I like trying new things.

Uploaded with ImageShack.com

Bill McCassey

Congrats.
Bigger isn't always better. It's all about how everything works together.

robz

Go to Tune Time Performance shootout at Atco in November and we'll help you out.

mchicia1

Sweet, got a link to more info?

MStrahan

Bill, Call my wife ASAP. I've been telling her this for years. Maybe she'll listen to someone else.

Bill McCassey

C5 Pete

http://forums.corvetteforum.com/perf...r-shut-up.html

quickc5zo6

What did it dyno before and after?

mchicia1

No clue, I don't dyno anymore. I just test and tune at the track now.

It probably made less peak, but 20-30 more ft/lbs in the mid range I am sure. I had to pump my VE table up a lot in the 3000 to 5200 range indicating it was making more power there. I had to reduce 6600 and up, indicating it probably made less power there.

quickc5zo6

Overall you gained average horsepower. That helps big time especially with trap speed when you get that big drop in rpm going into 4th.

PEETYZ

Under the curve is huge. Good results man!

Where did you get the As cast ls3 heads (small bore style)?

Cost?

I have a buddy looking to do some heads on his LS1. I know you cant beat Ls3 for the money but knew they didnt initially work with our bore.

These seem pretty nice. Ive got CNC 5.3 heads on My GTO and like them but just exploring some different options for him. Cost vs performance wise.

-Pete

mchicia1

They are BSP as cast ls3 heads.

They are cheap for brand new heads with brand new valves IMO.

http://ballisticspeedparts.com/shop/...6-ls2-engines/

The entire top end, ls3 Heads, ls3 intake, ls3 injectors, rails, ls2 throttle body, cometic gaskets, and valve springs ended up costing like $2200.

I gained a documented 50 hp, but I am also still using just exhaust manifolds.

It's a good setup, just gotta make sure you can bring the compression back because the heads are big. 70CC. I milled them .030" and got the .040" gasket. The problem is I am using a lower compression forged motor already so I am still only around 10.4:1 even with all that.

If my car had a stock block, I am sure I would see 122-123 mph. A full blown stock block car, with catless 1 7/8" heads and the same top end as me would probably run as strong as any other H/C/I car. The big savings in this setup is the fact that you don't have to get a FAST or injectors. That is about $800-$900 in savings right there. You just get the intake/rail/injectors as a unit, typically for $350, then you just buy the FIC injector connector adapters.

I really ****ing love this setup, but I just wish I never forged my motor and just did a stock rebuild. I am finding more and more every day that I just don't need 600 rwhp. 450 is just right for me, which I would have hit with a factory rebuild. You can have more fun more often with 450 rwhp too because you won't break parts.

mchicia1

If anyone decides to try this setup, don't reinvent the wheel. I am on my 3rd cam for a reason .

Bigger cams won't work at all unless you have 4.10s and you want to spin to 7k. The 231/239 did not work at all with 3.42s.

The 224/230 worked pretty well, but the ICL was too high. It was on a 115+0. A narrower LSA would have worked well.

The 219/231 with the narrow LSA has worked the best so far and that was the only one a pro selected .

PRE-Z06

DCR is much better with the smaller cam making more power down low and wide split carried it out up top, big cams only work well with compression which you're lacking and your head flow doesn't favor the exhaust so it needs some extra duration to help efficiency...wish you were closer to go to the track with, I'd definitely go the rental to get some good tips

mchicia1

**** I'd just hand over the keys to one of you guys lol.

mchicia1

Another posted his dyno of ls7 manifolds. While they do make the same peak power as headers, it appears headers will still pick up a lot more in the mid range even in a small 347.

http://forums.corvetteforum.com/perf...post1585262552

PEETYZ

Thanks for the info! Solid setup man.

PRE-Z06

Haha, though I've made passes in other's vehicles I still hold back when it's not my own...I prefer to help teach them to be better drivers and get the self satisfaction of doing it themselves

Yeah the longer primaries promote torque, I'm trying to convince our tuner to put the LS7 manifolds on his LS3 car with my sleeper cam and see if he can't pull off a 10.99 with my drag pack...

1BADAZ50TH

Recently swapped my bigger Comp cam out for a smaller cam chosen by Ed Curtis and gained noticeable torque throughout the mid range and only lost 13 peak HP. Car feels like a street machine now and don't have to wait for the power to kick in.

mchicia1

Yep, peak power really doesn't mean much. Average power from 4k and up wins races.