Anyone Ever Used A Cartech Gt40 Upper?

[ratio411]

Just curious what to expect out of it.

The car has plenty of gear, so low end torque loss is not a huge deal.

The car is eventually going heads and cam, but we were going to swap the upper on early just for giggles. It currently has the Exploder upper and 1" spacer. We'll keep the spacer and lower in place and just swap on the upper.

Thanks!
Dave

 

[TOOLOW91]

I have a downs box which is made by cartech essentially the same on my 317 stroker that i just put in my car and i like it alot so far, sacrifice a little low end torque but it goes it feels good up top

 

[ratio411]

Thanks Jeff.
Pretty much what we were thinking, I just wanted to hear it from someone who tried.

We put it in the Engine Analyzer, and it showed an increase in torque and hp both, but moved the peaks up in the rpm band.
It flattened torque curve, but moved it up 1500 rpm.
The peak hp occurs at 5500 instead of 4500, and falls on it's face after that, but this is modeled with stock heads/cam.

 

[ratio411]

Well, we put the intake on the car today...
Holey cow!
LOVE IT!

Off idle is a bit soft, but nothing worth much discussion.
It actually helps because wheel hop in this car was devistating before, and now it is much more manageable.

I bet the car picked up 30 hp...
In gear, at 3k rpm, stab the throttle and it is up to 6k before you can even react.
This thing is SOOOOOOOOOOOO much more responsive at just about any rpm above idle than the Exploder upper.

This is with a bolt on only stock engine, T5, and 4.10 gears.

I can't wait to see what happens when the heads, LT headers, and Z-cam go in.

It's my son's car, but I have a blast helping him with it. I drove it and hit 'valve float' so fast it was crazy. I am more aggressive driver than he is... Valves (totally stock valvetrain/heads) float about 6300 rpm. I told him to get an rpm activated switch so we can set up a shift light. The revs go so high so fast, that a light would be a good addition, and normally I don't care for a shift light.

 

[ratio411]

I know I sound like an excited little girl... but I have owned some fast cars before.
It's just that the whole 5.0 EFI thing is new to me.
I am used to carbs on Fords, and LSx engines for fast EFI.
To see this 5.0 we worked so hard on, and on a teen's budget, react this well to our mods has me giddy.

Including the aquisition of the car, we have less than $3k in the car as of today, and it is getting close to LSx performance. (Granted the car is quite a bit lighter than most LSx cars.)

 

[Gearbanger 101]

I wonder if it's not so much the cartech upper, as it is the explorer lower that is responsible for the bulk of your gains. The stock lower is said to be the most restrictive piece of the top end....so replacing it with damn near anything has to be a huge improvement.

 

[ratio411]

I wonder if it's not so much the cartech upper, as it is the explorer lower that is responsible for the bulk of your gains. The stock lower is said to be the most restrictive piece of the top end....so replacing it with damn near anything has to be a huge improvement.

The Explorer upper and lower have been on the engine since day one.
(Along with the 65mm TB)
The only thing we changed yesterday was the uppers.

 

[ratio411]

I was conversing with tmoss recently and he said that the GT40 lower is a very good part, and it's the uppers, in general, that are restrictive.
I heard what he was saying, but it didn't sink in so well until now.

Edit:
Tom said that the GT40 uppers were restrictive in relation to another brand upper.
I took away that the GT40 uppers were not the best, but that may not have been the intent of his words.

 

[ratio411]

Couple pics...

 

[Gearbanger 101]

Compared to a lot of the other aftermarket castings out there.....yes, the GT40/Cobra/Explorer upper is a little on the weak side. Compared to the stocker....it's a god send.

Guys have run 11's on stock GT40 intakes, so they can move some air if need be. I'm sure the Cartech is moving a lot more air in the upper ranges than any of the Ford units though.

 

[TOOLOW91]

those are my thoughts weak on the bottom but up high 3-6k like you said you feel the torque hold on !

 

[ratio411]

I was amazed, even though I probably shouldn't have been, at how fast it gets from 3k to 6k.
The factory GT40 upper got from idle to 3k pretty quick, but after 3k it was lazy and slow to rev up.
The situation is reversed now, but the 302 loves to rev due to it's short stroke, so an intake that can rev like this plays to the engine's strengths... not to mention having the T5 and 4.10 gears. The car just LOVES the revs.

The LSx engines are the same way. From a dead stop, they take a second to catch fire, but from a roll they are deadly.

 

[ratio411]

We have 2 other 5.0s, my other son's 94 GT and my 87 GT.
I know for sure I am putting a box on mine now.

I'll probably leave the Cobra intake on the 94, just to keep it simple, and being an automatic, it might act sluggish.

I'll be looking for a Cartech upper for the 87 though. If I can't find one, I'll use another brand.
I like the Trick Flow until I see the runners inside. With so many dead end surfaces inside, I don't see how the air can flow smoothly.
The Cartech, and I assume the Downs, have the runner tops blended to the plenum, with no flat surfaces to disrupt flow. Just an observation from a visual perspective. I could be wrong about the multitude of flat surfaces inside the TF. ???

 

[srtthis]

one of the fox's i was looking into getting had one on it but it was a turbo car down south. i didnt go for it since id have to fly down and drive it back from atlanta and it could have turned out to be a piece. but you dont see many of them out there