Intriguing dyno numbers

[Hissing Cobra]

Hey everyone, yesterday we took my twin brother's '85 GT to the dyno to test the rwhp and rwt of his freshened up 306. His combination is identicle to mine except that he has '69 351 Windsor heads that he ported/polished and added bigger valves (vs. my AFR 185's) and his camshaft is one size smaller than mine.

The results floored us! My combo made 307 rwhp and 279 rwt and his made 311 rwhp and 287 rwt. The strange thing is that my car was running a little too rich on the secondary side of the carburetors so we had to change the jetting down one size. His ran lean and we'll have to increase his up one size. 8O This is the same engine that he made 291 rwhp and 272 rwt back in 2000. We were both stoked beyond belief.

We also brought a friend of his who has an '86 GT that's naturally aspirated. My brother built his engine and performed all of the bolt-ons for him. His car dynoed at 308 rwhp and 330 rwt! Of course, he had to invest in a chip burning to keep the computer in check but it was well worth the investment as it was continually running lean on him. Not anymore!

If anyone needs their car dynoed in the Massachusetts/Rhode Island area, I highly recommend Mike Dez Racing in Seekonk, Mass.

[Zap's 85 GT]

Guess its all in the combination. And perhaps the old antage that says cast iron heads make more power because they keep in more heat seems to hold true in this instance.

Just to clarify, he has the same dual quad setup that you do?

[Hissing Cobra]

Yep, other than the heads and cam, the combo's are the same. He thought when he was building mine, that we'd make more power with the larger cam and aluminum heads (which also saved him 14 hours of porting/polishing.) We learned a good lesson!

Nonetheless, we're both happy with what we've got. ;)

[Zap's 85 GT]

You guys make me soooooo much to want to get my 408 done. I need money that's just going to take time to gather up. I need another parts car.

Since I moved here to Florida I'm content for a little while in the fact that I picked up almost 40hp going from >5000' elevation in New Mexico, to sea level. The Mach 1 can now roast the tires from a roll.

[Hissing Cobra]

Sweet! That 408 will get you movin' too. Get it built!

[anthonydalrymple]

Yes, the combination does make a world of difference... I was at a Mustang only dyno day this weekend & a clean black notch rolled up onto the dyno. I noticed the motor looked just like mine... RPM II intake, afr165 heads, 24lbs inj & Granatelli mass air, etc. I talked to the guy & the only differences were that he had a "E" cam & the air was still mounted to the motor. Dyno'd only 260hp & 280tq at the tires. I figure with some good tuning, a chip, & a few minor "intelligent mod's; he'd get 280+rwhp & 300rwtq....