Back in the mid 2000's their was a guy that would show up to a few F-body dyno gatherings with a red 750+hp TT Supra. Back then I never knew those cars could make that much horsepower. He'd come out on top nearly every time at the end of the those sessions as the king of horsepower over some stout stroked, blown, n/a nos LS1's. Love them or hate em you gotta respect some of them if they're still on the road!

 

750 is nonthing....Those things can get up around 1500 rwhp!

 

your sure it was 1989, on the dot?? lol

 

Oh I'm too sure...not one month past.

 

Cool
I am a Supra owner that loves races from a dig!!!

 

Supra's Making The Import Kids Cream In There Pants Since 1993 (Mark IV)!

 

When it comes to 180mph+ roll on's it hard to run down a GT47+ Supra thats built right. The drag coefficient on an Fbody is just not as good as the Supra, and their heads in stock form outflow most of our high dollar heads. Their transmission is better and the ride at those speeds is much more stable. They cost a fortune though to make 1200-1500rwhp, and they break quite frequently at those levels as well. You can easily maintain an exotic for the same price as a high end built Supra. The best thing GM has made to run one down would be a well built turbocharged, LSx blocked, C5/6 Vette. You would want the standard C5/6 as it has a Drag C/O that is very close to the supra if not a little better, and with the LSx you can up the boost to run one down.

 

No.



225cc AFR heads (3.900 bore)


225cc AFR heads (4.125 bore)


245cc AFR heads (4.155 bore)


CNC Ported Stage 3 GM L92 Cylinder Heads from Livernois
Intake Flow Rate 360 CFM
Exhaust Flow Rate 245 CFM (275 CFM w/ 1 3/4" Pipe)
(couldn't find a graph, but you get the point).

None of those AFR heads are even ported yet (quite affordable both before and after porting as well).

 

Not just drag coefficient, frontal area. The Supra has a decent frontal area though.
Honestly though, drag area isn't a huge deal from a roll until over 150mph and most don't race that high.

Even then, it isn't a factor that more power can't solve.
For example, a Ford GT has a poor drag area, but still has the record for standing mile at 26Xmph (somewhere around that).

 

Exactly, and the supra holds the FR record for the standing mile with a high 25x.

 

Ok, so lets go with the big boy 245cc heads you have posted above. Lets assume at least 7L of displacement (427). Then you take that little 3L from the Supra and its 183 cubes. The dyno record for a stock block/untouched head Supra is 1044RWHP. To make that number pertain to this conversation you would take the massive 427 and divide it by 183 and get 2.3333333333repeating. You take that number and multiply it by 1044 and you get 2436. So how many 245cc headed street cars you know of are pushing nearly 3000hp at the flywheel?

427/183=2.3333x1044=2436x.20=487.2+2436=2923.2 That would be the math at 20% power loss.

A 245cc head may have more CFM capability than the Supra head, but it doesn't have more velocity with all things equal. If the stock head of a Supra can push 1044rwhp and not bottleneck on 3L why can't the 245cc headed 427 push 2923rwhp at the same levels? Velocity over CFM any day in turbo applications.

 

Most may not race that high, but "most" don't have 200+mph standing mile street cars either. If you hit up TX2k11 you need to bring a 145+mph quarter mile car if you want to even stay in sight at times with the big swingers down there. As for frontal area, I left it out to keep it simple. The Viper has a large frontal area and it hits its wall around 200 or so. After that it has to use all of its literage to put up big numbers to pull on. Supra has a nicely balanced shape and shows it out there. Ford GT seems to be moving to the front of pack as it has a small frontal area and better than average aero for the event. Your correct about the Ford GT. The mph was 266.9 just so you know. Heffner ran it.

Actually it is a Ford GT at 266.9mph as stated above.

 

He said FR record, as in Front engine Rear wheel drive.

As for the heads, there are several stock LSX headed cars with over 1000hp.
As you know, it's more about air flow and velocity than it is displacement.
If you're primary argument is head flow, then displacement is irrelevant.

Oh yeah, and two heads flow better than one.

 

This +100000

Also quite frankly, you said head flow. That's the only issue I had with your post, and you built a straw man argument to knock down after your original statement got shot out of the sky. Ricer math is frowned upon here at LS1tech.

 

I didn't post any ricer math so leave the insults at the door. I simply showed you what the efficiency rate of the heads allow for when each is placed in direct and equal competition with one another. If a Viper head had the same volumetric efficiency as say a Type R head we would see a large amount of 2000hp Vipers running around, but it doesn't. Volumetric efficiency will never be ricer math. It is however scientific fact. Nothing wrong with that. I respect engineering. I 'm not very brand loyal as I look to whats out there, not always to what I own. I didn't see a straw man argument, I see an example of what a 2JZ head can do in stock form and what a 245cc head can do on the correct motor. You are very right in statements about which head has more volume and that two heads can flow better than one. But your missing the context of what those heads are designed to bolt to, which seemed obvious to me, but perhaps I should have elaborated on since that basic conceptualized idea is lost here. If the head is not the limitation of a 7.0L 245cc headed LSx motor, then what is? Those heads have a whole lot of volume obviously, but they need a 7.0L or larger displacement block to push the air through. Displacement is extremely important when determining what a head can do. You see larger CFM's on bench flow tests, but the numbers are irrelevant without the basic essentials the heads are built for. To much flow on a certain engine and you can't hold boost and to little on another and you end up with a bottleneck. The big 245cc heads need the extra displacement of the 7.0L to create the velocity needed for these heads to work properly. The Grand Canyon has an incredible amount of volume, but it has little velocity compared to say a jet engine. To make that relevant if you take the mass of air at any given point that passes between two points in the Grand Canyon and place that number againest a jet engine that is 2.3x smaller than the Grand Canyon pushing air at the same points, in theory they should both push the same amount of volume through. So which one is more efficient? The smaller jet engine as it can push the same volume through with less size. The 2JZ head has a higher volumetric efficiency than the 245cc head. The 245cc head has more volume than the 2JZ head. The more volumetric efficiency a head has the higher it can rev to. A stock 2JZ head will hit 9000rpms, with valve springs being its limitations, not flow. How many V8's you know of can achieve that? We can just choose to disagree.

 

Correct me if I'm wrong, but you said: "their heads in stock form outflow most of our high dollar heads." You weren't arguing volumetric efficiency, you only addressed flow capability. There are stock LSX heads that flow better than a stock 2JZ head.

You wanna look at a head with serious flow potential, look no further than ported Cobra B heads. Not C, B as in boy. They're efficient and flow well enough to power a car with a 4.6l to times quicker and faster than any 2JZ powered car.

 

I'm sure you had something important to say, but I didn't read it. Actually I lied, I read the first sentence, laughed, and then stopped reading. No insults anywhere in my post

Here you go.
http://lmgtfy.com/?q=strawman+argument

You tried to say 2JZ heads flow better stock, better even than LSx high dollar heads

I posted information on the contrary

:Brace for Strawman:

Switch topic to volumetric efficiency (not something we were talking about...well, at least I wasn't lol). And back up with maths. It's very easy to beat up an argument that we weren't having in the first place haha

 

The head I care about is when it comes from the female brand..give it a rest..Everyone knows any LS1 vehicle is better than a supra..Even I would roll a lowly 2004 GTO before a supra..

Supras braker like their is no tomorrow.The guys usually have a boost leak or are on their third engine ect...The LS1's with an agressive head/cam set up are reliable 10 second cars