Elysian

I know . . . LT1 crap probably doesn't belong on an LS1 forum, but CZ28.com doesn't have a dynomometer section . . .

I went to AP Engineering for a dyno tune last Wednesday. Mods are as follows: Stock 350ci bottom end. 195cc AFR LT4 heads (203 cc after porting) flowing 280cfm @ 0.580 lift. Comp Cam from Combination Motorsports, XER lobes, 233/239 at .5, 283/289 advertised .569/.577 110lsa. Hooker longtube headers (no cats), Corsa catback, Ford 9", 17 X 11 wheels w/ 315's out back.

Dyno'd 368rwhp at 6200 rpm and 325rwtq at 5300 rpm on AP's Mustang Dyno. I was pleased with the torque. It would have been nicer to have a little more, but it is flat as a board from about 2500rpm on up. As far as horsepower goes, I know - 368 souunds low (especially on an LS1 forum). And according to the tuner it is low, by at least 12-15hp at the wheels. Based on the graph and some other things, he said I have pretty bad valve float. This really pisses me off - I bought the entire valvetrain from Combination Motorsports - and here's the kicker - it is THEIR cam: Comp only grinds this cam for them. So WTF? They send me springs for their own cam that are inadequate? This cam should be peaking somewhere around 6500-6700 rpm, and the hp/tq curves drop like a stone after 6200.

I figure I'll have to pick up some new springs (or be happy shifting at 6000 - not likely). Seems to me like I should be getting a FREE set from Combination Motorsports, but I'll believe that when I see it. Anyway, assuming I can hit 380-385rwhp after a spring swap, what do these number translate to on a Dynojet? When I put this package together, I was hoping to hit 400rwhp. Kinda disappointed. Anyone know what I could gain from an electric water pump? Pulleys?

big dave

I think you should be seeing a bit more power with that combo. That really is a decent sized cam for an lt1. Get those bugs worked out and take 'er to the track.

98Mayhem

iTrader: (18)

Those are great numbers for a mustang dyno.

JS

iTrader: (4)

We hit 404/416 SAE on our final tune on a TEA S3 LT1 headed 383 w/Speed Pro.
The car is an animal to 6800

This was threw a A4/12-bolt 4.10 and makes 400RWTQ from 3200 to 4800
The car has a dead flat hp curve and its making 350RWHP by 3000 rpm.

We didnt set the dyno on fire but I bet this car lays down a number..

Elysian

I know Mustang Dyno's throw up lower numbers than dynojets. What do these numbers work out to at the motor?

Elysian

I live in Quincy, MI, 49082. I've never been drag racing (legally) with this thing before . . . Where is the closest track that is decent?

98Mayhem

iTrader: (18)

I would say to add about 25hp at the rear for dynojet numbers. What transmission do you have?

Elysian

six speed.

Parker TX

iTrader: (16)

if you want to see 400, strap it to a dynojet.

Elysian

No one has numbers on what underdrive pulleys can do?

ZaneO

Have you contacted Combination or do you just rant on a forum?

Doesn't seem like those numbers are low...Mustang dyno's are significantly lower. The 9" and 315's will cause the numbers to be lower, too.

FWIW, my full bolt-on LT1 put down 338 rwtq.

Elysian

I have put in several calls to Combination Motorsports and they can't be bothered to return my messages. Until they do, yes, I am ranting on the forum in an effort to prevent them from causing people like YOU from having the same problems I am. So you're welcome.

jaberwaki

exactly.
same car on a dyno jet,
10bolt
3.42 gear
245 tires. 410-420 rwhp

IMHO

Elysian

Has anyone EVER hit 400rwhp with a stock cube LT1 on a Mustang Dyno? (Naturally aspirated).