[1972GTOmachine]

Hi guys,

An week ago i have chassis-Dyno my Gto with this results:

406 HP , and 604NM torque .

How much horses and torque do i have on the crank?

Where is the weakness of this engine?(where can i took some more horses).
Where can i make this engine more powerfull?

*My car specs are:
-Pontiac 1972 GTO.(all steel)
-TH-400 aut trans.(1972)
-10 Bolt , 3.08 gear.(1972)


*Engine specs:
-Pontiac 474ci engine.(455ci,1972).
-Edelbrock alu heads 87cc (out of the box).
-Wenzler street tunnelram , with 2x edelbrock 600 cfm carbs on top.
-Crane Hydrolic roller cam special:
0.50@ int dur :242 degr , exh dur:252 degr.
Power-range:3000/6800rpm.
-Crane hydrolic roller lifters.
-10.25:1 compr.
-Harland/Sharp 1.5 roller rockers.
-Doug's headers.
-Flowmaster 40 serie mufflers.
-rear tires are 295/50R15 BF goodrich radials.


*I want to use this car for street/strip.

Thanks for reply,

Eddy

[screamingchief]

The only improvement your gonna be able to make without any negative consequences would likely be to increase the head flow numbers (further head porting).

More compression will make it less tolerant of most pump fuels (except maybe E85).

You got a little room to tweak the CR with the Eheads,but I would'nt go too crazy here.

More cam will almost certainly reduce the "street" friendly qualities.

It likely would put up better numbers with a well chose single 4bbl intake & carb,but I understand why you might not wanna change that,the visual impact is up there with the current set-up I'm sure.

If the Dougs headers are the 1 7/8" pieces that could be an area to reconsider,but that would likely be a crapshoot as far as any gains are concerned.

Losing the flowmasters might gain some too,there are better flowing mufflers out there if every last hp matters to you.

As far as driving the car,the '72 is pretty heavy,I'd want more gear,at least 3.42/3.55 @ the minimum.

And what torque converter is in this???

That's an area that can really make a difference in terms of how a car actually performs on the street/track vs. the numbers you'll see on a chassis dyno.

I dunno really,honestly those numbers are'nt too shabby at all,considering they're @ the rear wheels.

[1972GTOmachine]

Thanks Screaming chief,

I have make a mistake with my combo in the list!!
I have dyno the car with a Torker 2 intake and 870cfm on top.

I have use a cut tool from a other topic of me , and forget to change the intake with carb.

Sorry about this!.
The Torque converter is a Continental 3000/3200 rpm stall.
What E.T. do you think with this car/combo?

Thanks,

Eddy.

[1972GTOmachine]

And How much Horse/torque should it have on the crank?

Are the Torque numbers nice for a 474ci?

Thanks again,

Eddy

[steve25]

You have way too much manifold and carburation for stock flowing E- heads( too little velocity!) and with that cam and that size motor, your power range is well done at 6000 so thats another reason you have too much manifold.
You did not state the valve lift, but these big motors love a fast opening cam lobe and going to 1.65 rockers and the right lenght push rods to run them will be worth a good power increse!
If you are running the springs that cam with the heads you will need to change them to run the 1.65 rockers E states they are good to .575" lift, but above .530" they suck!