[acgwinn]

My friend has a 70 Judge with a Ram Air III and a 70 Trans Am with a Ram Air III. They are the same exact engine, but the Judge is rated at 366 HP and the T/A is rated at 345 HP. He said that he thought he read somewhere that it was because of the exhaust manifolds, is that true? Or is there some other reason? Thanks, Damian.

[70ram4]

i believe the carb has a restrictor on it, ( linkage ) memory is foggy at best.

[Baron Von Zeppelin]

Same engine, same exhaust manifolds.

T/A had better induction and better exhaust system. BUT supposedly had a limitation on the throttle linkage to slow it down behind big bro GTO.

Un-corked, the T/A will ALWAYS lead the way.

(oops, wrong forum for that answer)

[The Boss]

Don't worry BVZ, they won't hate you for it - honesty starts at home.

[giles]

The engines are the same. If the engine were unique to a carline it would have had a unique "broadcast code", WS for a '70 RAIII manual, for example. When a "WS" engine left the Pontiac engine plant it could have headed for an A-car or an F-car. There may be some actual difference due to the air cleaner and exhaust systems, but the REAL reason they are rated differently was due to the corporate mandate that limited max advertised HP based on HP-to-weight ratio. The undeclared maximum ratio was 10 lbs per HP. A-bodies weighed roughly 3700 lbs and F bodies 3500.

[Lloyd-TX]

Agreed that the rated HP was strictly a numbers game to get the HP engines past GM brass, but truth be known the GTO engine would have more RWHP due to a BETTER exhaust system than the T/A. No way the OEM single transverse muffler flowed better than true duals on the GTO.

IIRC the Firebird Ram Air engines did indeed have the secondary air valve travel limited to reduce peak HP. Easy 10 minute fix for that though!

Funny how Chebbie got preferential treatment - rating their L88's ZL1's, LS6's, etc. MUCH higher than 10 lb/hp!

Besides, back in 1970 gross HP ratings were used, rather than the net ratings beginning in 1971/1972. The gross ratings were open exhaust, open air cleaners, no accessory drive loads, etc.

[ramair2]

"Agreed that the rated HP was strictly a numbers game to get the HP engines past GM brass, but truth be known the GTO engine would have more RWHP due to a BETTER exhaust system than the T/A. No way the OEM single transverse muffler flowed better than true duals on the GTO."
====

thats true lloyd (even though transverse muffler did help equalize backpressure to some degree)...STILL...regarding 68-9 fbodies...the first gen roundport fbodies had much better flowing exhaust manifolds over their abody ra 2/4 counterparts...

that plus the 300+ weight advantage definitely added up to a faster fbody (vs a-body) in 68 and 69...

oops! BVZ-style ;-)

[Baron Von Zeppelin]

I thought the early T/A exhaust systems like 70 T/A and 73 SD T/A were supposed to be the best mufflered performance system - excluding chambered/resonator of chev. May be another myth for the busters. idunno

68 & 69 round port Fbodies are just too mean to be seen. Taboo stuff

Damian I hope we helped you and your friend understand the advertised HP numbers for all Ram Air II, III and IV are just poetic factored math in print.

III's were around 375+ fwhp and IV's were over 400 fwhp. 345 366 and 370 were weak representives to keep corporate headquarters passified and off their case. B-O-P were supposed to know their place - 2 or 3 steps behind chevrot. If you didn't make waves they don't strangle you as hard - I think was the goal.

Have him build both his 70 III Cars engines the same someday, and see which one feels 20 hp slower.

[acgwinn]

Thanks guys. He just finished his Judge restoration and will be tackling the 70 T/A soon. I think i have a pix of his judge somewhere. If i do i will post it for you guys. It's a beauty. Take care, Damian.

[442w30]

What about weight transfer? I've held the belief - rightly or wrongly - that the GTO would probably win.