69ls6

iTrader: (5)

car is 98 camaro m6 through a 9inch.put down 462hp and 441 tq.build is tsp bottom with -6 pistons,afr 225 heads,untouched ls2 intake with elderbrook 90 tb,1 3/4 pacesetter headers and cam is 250 257 630 645 on 112.comp ratio 11.2 to 1.this was through a single 2 1/2 exhaust pipe with no muffler.I got 1 7/8 headers not installed yet and was going to port intake and cam may be to big.I know headers,intake and the 2 1/2 wxhaust pipe is hurting but will that pick up 70 hp thay I thought it should make.

bjamick

iTrader: (31)

408's are usually in the low 500 mark na.

MikeG

iTrader: (33)

You already said it man. The LS2 intake is horrible, your exhaust setup is horrible. Get the new headers/exhaust on and get rid of that intake for a FAST and you should break 500 no sweat.

ScreaminRedZ

iTrader: (3)

^What he said. The current power doesn't actually look that bad when you look at the whole setup. Driving it as is for a little bit will make the car feel really good when you uncork it.

69ls6

iTrader: (5)

what I have seen around 20hp for 102 fast but I also seen 15 hp from porting ls2 intake.hate to send 800 on 102,375 for nick willaims tb and just gain 5-8hp when I can spend 300 for porting ls2..alot of money on fast..has anyone seen dyno numbers similar builds,what gains from what intake..mast motorsports seems to get most power but u have to run 6'' cowl hood.

gtotoocool1

iTrader: (6)

i don't know about 70hp,but the intake/headers and exhaust is definately holding you back.
i would imagine that 2 1/2" exhaust is choking things pretty bad.just installing the 1 7/8" headers and a bigger exhaust alone will probably pick more HP than you think.

69ls6

iTrader: (5)

does the cam specs sound good

Tunink

iTrader: (3)

That LS2 intake and exhaust is definitely killing it for your combo.

*02WS6TURK*

iTrader: (13)

Throw your LS2 in the garbage and then at least upgrade to a LS6 or a Fast 90/92/102.

jimbob

iTrader: (4)

I wonder what your DCR is, with that SCR and cam (not very high, I bet). Quench height is also important..ABDC of intake @ .050 is important so you don't get a double TQ peak. Don't go over 52 degrees (with those cubes), if using a stock or FAST manifold. If it is past 52* now, it may some times not show up on a dyno, you'll just have less tq than you should and can't figure out why. 462 would be good on an unlocked big stalled auto thru 9inch. My friends 402 car does this with a bunch of parts that he had off his 346. I just spected him a cam that will pull to 7200 (for juice). It's first day NA it ran 10's (3650lbs race weight) with 3.4 gears and 28inch taller tire, he was happy. That combo should pick up a tenth or two now with the correct gear and setting up a shift point.

Jim

LIL SS

iTrader: (9)

My 418 going through the mufflers made 498rwhp. Uncorked it made 521rwhp. That was through a 4L80E, 12 bolt w/ 4.56's and a 315/60/15 (30") drag radial.

My exhaust consists of 1 3/4 stepped to 1 7/8 edelbrock headers wih 3.5" High velocity merge collectors knecking down to 3". Then it had dual electric cut outs before knecking down to dual 2.5" exhaust and turbo mufflers.

If yours is going through a single 2.5" pipe, I'd imagine it is muh more backed up then mine and mine is backed up through the mufflers.

69ls6

iTrader: (5)

the car is a m6.430 gear.I bought the car with most of these mods.I am going to order a vengance ported 102,car ran a 11.47 first day the track opened.with a 1.9 sixth and spinning through 3rd..1/8 was 7.5 @96 trapped 125mph.on the car didn't pull past 6300 I figured due to intake.while i'm changing intake and headers I was going to change cam.everybody has a different opinion on what cam spec should be.LG said cam was to big they would put a g6x4 in,tsp said cam was to small and would go bigger duration..

gtotoocool1

iTrader: (6)

honestly i wouldn't worry about the cam at this point.get that thing uncorked.like i said,i think you will be suprised at how much the headers/exhaust(and intake) are holding you back.
with the AFR225s and 408 cubes you are moving a lot of air.your headers and exhaust are basically what is run on a 346ci engine.

jimbob

iTrader: (4)

Made some quick calculations...That cam better be advanced 4 degrees or your off (your low in dcr anyways)......With 4 degree advance you would be right at 8.0 DCR (not good) and 53 abdc (ok). If it's only advanced 2 degrees I come up with 7.85 DCR (bad) and 55 abdc, not good and will kill tq by either giving two peaks or just a lower tq. Your going to lose tq and hp with that low DCR anyways. Your going to lose some from your exhaust (true), intake (true). But not 60 or 70 hp. Sorry, it's a combo problem (PERIOD). Anything that will get your DCR up, will help. So, proper cam, exhaust and intake will make that a monster guaranteed. I would go with something like a 245@.05 cam with 295 base duration, with 110 lsa and ICL of 108. Just add 6-10 degrees more on the exhaust side. Normally, with something that low in SCR, I would go 240 intake @.05 and 289 intake base duration on a 112 lsa, 110ICL. That would give you 8.25 ish DCR and still put your abdc@05 in the 50-52 degree range. Either cam would work.

As a reference, the cam I spected for the drag/show car was in the 236 intake duration because of his low 11.0 scr. And with all his mismatched parts thru cat converters, 9 inch with way to tall tires on to tall gears and it still ran 10's first time out...

Get a hold of Pat G and he will spec you a cam. He will ask you a lot of questions to get you the right cam (I don't do this on this board, although I have been specing cams for 16 years now) so, I don't step on toes. He will do you right....

Hope this helps..

Jim

gtotoocool1

iTrader: (6)

11.47 ET with a crappy 60ft,while spinning thru 3rd and trapping 125mph..get the traction issues sorted out and he's damn close to 10s as is.so i don't think his cam is that far off,if at all.i don't spec cams and no disrespect intended to you or your experience.all i'm saying is get the proper exhaust and intake on there,then see where he's at before throwing more money at it and tearing into the motor.if the results are not there after that's been done,by all means look at the cam..

jimbob

iTrader: (4)

None taken..Re-read his first post. Your also making the assumption that 125mph is good. You ever wonder whats the race weight is, or DA he made that pass at. If any one wonders why you can make 500 rwhp (dynojet) on a 346 bottom end....It's the combo. I would have no doubt with a ported FAST (he's getting) and some 1 7/8 headers (he's installing), and uncork the exhaust, that he would pick up 40 hp. But 500rwhp with AFR heads and that size cam on 408 is 10 years ago power (I know, we used to do these combos with old ported LS1 heads, ported LS6 intake and make that kind of power). We're also talking peak power vs. what's under the curve, and that can't be good. These engines can make great power if your willing to invest some time in them...

A few things he could do instead of pulling the cam, have your heads shaved to pump compression and use that cam that's already installed. You get that comp to 12 and you'll pick up big time with that combo. Or go great single plain manifold that doesn't care about late abdc of intake (it would help some). But these will just make more work than maybe he's willing to do right now. If this guy is satisfied with 500 that's all that's important. That's surely more than enough to get you in to trouble.

With everything done, and from where you your at now, I would expect to see you at 131-133 trap speed..And low 10's with a good 1.4 sixty foot.

I can tell you that even I'm not going all out on my newest combo so I under stand where your coming from. I'm not going Cary's single plain and instead I picked up a Ported 102 Fast. I'll be leaving 40 hp on the table, but I like my stock hood.

69ls6

iTrader: (5)

when the intake is being removed so will the heads,shaved to 12.5 to 1 already using .041 gaskets to get what it has.car is full weight,nothing removed but front bumber brase.I have a 3.89 gear on the way running 4.30 now ,1st trip out with 28'' drag radials went through at 125mph @ 6800 rpms,slicks r 26''.don't have money for intake right now,shortly...THANKS FOR ALL THE HELP.GOES FOR ALL OF YOU GUYS..

jimbob

iTrader: (4)

If your going 12.5 comp leave that cam in there. Verify your spring pressure though, as you said it does not pull well in the upper rpms (And that could well be just your stock manifold nosing over). With that cam, compression, intake and exhaust 550 seems very possible with that manual tranny car....Good luck on the combo...and keep us posted...

Here's my latest combo.. 12 to 1 comp LSX 427. PI (Carey's/Mast) LS7 heads, Fast 102, Nick Williams 102TB, 25Xish .66X lift cam, e-pump, AR headers and (CATS) "got to keep the people guessing at the track" ect. on E85... Looking for minimum 600 locked thru my 4l80e. With a 200 shot it should easily run 8's (what car shouldn't right).

69ls6

iTrader: (5)

[quote=jimbob;14699647]If your going 12.5 comp leave that cam in there. Verify your spring pressure though, as you said it does not pull well in the upper rpms (And that could well be just your stock manifold nosing over). With that cam, compression, intake and exhaust 550 seems very possible with that manual tranny car....Good luck on the combo...and keep us posted...

Here's my latest combo.. 12 to 1 comp LSX 427. PI (Carey's/Mast) LS7 heads, Fast 102, Nick Williams 102TB, 25Xish .66X lift cam, e-pump, AR headers and (CATS) "got to keep the people guessing at the track" ect. on E85... Looking for minimum 600 locked thru my 4l80e. With a 200 shot it should easily run 8's (what car shouldn't right).[/quote

does e85 help in hp and et times...if I could 550rwhp I would love it...like to run 10.30s then may put the juice on it for 9s

jimbob

iTrader: (4)

For E85, the numbers thrown around is generaly 3% more power. From what I'v seen at 12-12.5 compression look for about 15 more, maybe 20 rwhp (if your lucky) from the ethanol use. If you bumped comp up to 13-14 to 1 comp you can get more out of the engine. Really, E85 is not going to make much difference for timing requirments with our good heads, you'll probably still find low 20's work for max power and 2 or 3 degrees more timing added works for max torque. I'm finally swithching, we have a pump with 25 freeway miles now. If racing with it buy a cheap ethanal weigh set, just to make sure you have the same amount everytime you go to the track. On our more powerful 383 18* engine we're at 14.4 to 1. We will mix 109 with 90% ethanol. We will be ordering E100 and mixing our own. We could go 100 straight but you can never guarantee it's going to fire when it gets cold. Your in that compression range that E85 starts to really shine. There is some real good E85 info over at Corvette forums C6 section...

Jim