[transam1972]

does anyone on the forum own a 1970 T/A Ram Air IV?...and it being high compression were they "harrier" than the 1971 and 1972 455 H.O.s?

[2manyT/A'S]

This will spark a "lively" debate......

Pontiac actually had a TV commercial in 1971 that pitted a 70 Ram Air IV GTO againt a 71 455 HO GTO to show the performance was similar/equal.....

The Ram Air IV was "harrier" in a 1969 Firebird because of the cars lighter weight...

[transam1972]

I have seen that commercial..of course Pontiac wanted the new cars to win...but I would like to know real life...70 T/A RA IV against the 455H.O. T/A...does the last year for high compression in a Pontiac engine in the T/A body make a different animal?

[Dens71TA]

The extra 55 cubic inches on the low compression H.O. has to more than even the playing field with the high compression RA IV. There is no replacement for displacement!

[Formulabruce]

You'll not likely get a fair answer as most on here advocate modifying original engines when they are rebuilt.. your dealing with the "Stock appearing" crowd now... this goes for almost everywhere...
Aside from making it, you cant get the gas the 1970 car really requires.

[rexs73gto]

I'm not trying to highjack this site but please go to the post Loss of a friend & read them if you are a friend or know Bruce Zalai, he was a big SD fan & owner who we lost on wed. He had just turned 60 on dec. 2nd. Thank You for reading & rest in peace good friend.

[transam1972]

I am into keeping everything stock..pain about the gas though for 1970 and earlier owners...I knew along time ago my low compression engine was a good thing....what about the M22 vs. the Turbo Hydramatic 400...if stock...who wins?

[2manyT/A'S]

Originally Posted by transam1972

I am into keeping everything stock..pain about the gas though for 1970 and earlier owners...I knew along time ago my low compression engine was a good thing....what about the M22 vs. the Turbo Hydramatic 400...if stock...who wins?

That one is all about driver skills...providing ther rear end ratio is the same......MOST people can drive an automatic faster than a stick...

[The Boss]

Gears will make the bigger difference in what you feel.

Given the choice I'd take the IV any day of the week.

[Judge273]

The 69 and 70 RA IVs were beasts with HPs in reality terms closer to 500...Add the bigger gears and lighter cars you got a better comparison for the RA IIs which shared cams and comp ratings. 455 HOs are just good fun cars to drive to race, race, and go home with a smile...

[Formulajones]

You really don't have to look any further than the pure stock drags and come to your own conclusions.

Once you attend a few of these things, understand the rules, and build and race a car for it, you'll see which cars are the more advantageous packages and which are "lacking" performance.

Given the fact that the cars all follow the same rules, and run on the same tires, it's really the only true comparison nowadays.

For those that don't want to research, the ram air IV cars (including the A-bodies) consistently put up quicker ET's and higher MPH's than the few HO cars that participate. That's from what I've seen in person and participating myself.
Alot of that has to do with the more radical camshaft the IV's get right off the bat, coupled with more compression, they make power, usually in the ballpark of 400 rwhp on a chassis dyno when tuned and tweaked.
The HO cars lack a camshaft and compression, but they do make a nice torque curve. But with the tires being an equalizer so to speak, low end torque isn't necessarily a good thing. They do however put up very respectable times.

[transam1972]

o.k. so its possible to say a RA4 is less mannerly than an H.O.?..and an H.O. is perhaps more refined?....would anyone care to tell me how or what parts evolved from the RAIV to the H.O....thanks!!

[Formulajones]

I wouldn't say the HO is more refined, it's just a victim of strict emissions and lower octane unleaded fuel that was making the scene at the time.

The heads and intake were the major pieces from ram air IV development that were carried over to the 455 with minor changes (to keep the description brief). If the engine would have had the camshaft and compression ratio to go with it you would have had a very potent package. As is, it's still a nice performing engine that will run on the cat pee gas we have nowadays. So under those circumstances, in some peoples eyes it does make it appear to be a more attractive package.

[Mezzo]

Sounds like a time for a shoot out to put this to bed.

[Formulajones]

No better place than the pure stock drags, if you have something, bring it on out and have at it

[Jack Ferris]

Way to many variables. In a 1/4 mile from a stop chances are the HO will get out of the hole faster. But, I think because the RA IV has the ability to keep pulling where as the HO will fall off, the IV would beat it up. 18 degrees of duration @ .050 on the intake and 2 points of compression will surely out perform a 55 cubic inch size advantage. Now, recam the HO and things change completely. But were talking stock.

[Formulajones]

Stock is the only real comparison apples to apples, and I believe that's what most people mean. If you start modifying things to each owners tastes, well then anything goes and comparisons get lopsided

That's what is sweet about the pure stock drags, the rules apply accross the board so any gain or advantage you find in the rules is the same for the next guy.

[transam1972]

my engine is 100% stock...I hope to never have it rebuilt or modified...however, can a RAIV cam go in a H.O.?..what happens?..obviously I am sure there are other things to fine tune...interesting idea to upgrade a H.O. to RAIV standards,if only this was 1972...time span and gas what it is doesn't make it feasible I suppose...I am on the lookout on this forum for modified H.O.s...any ones thoughts on limited mods to the TH400?...such as a shift kit?, does it need it?...I wouldn't(I don't think?!)but a nice looking Dual Gate would be cool!...I have never been able to enjoy my H.O.perhaps 500 miles in my life??,

[Formulajones]

Plenty of people over the years have installed the ram air IV camshaft in the HO cars with "decent" results. However the engine really doesn't have the compression ratio to take full advantage of it.

One advantage you have is that the ram air IV cam is much more tame in an HO with 55 more cubes to soak it up. It's a swap that might be worthwhile to you.

[Jack Ferris]

The 041 cam runs very well in the low compression 455's. Probably not the best choice and if you are using an auto trans then it will feel like a slug unless you have some convertor behind it. But, they do run well.