Pros/Cons

[Arvin]

My SPF GT40 mk 1 is similar to what you are considering, and I have a couple of suggestions/opinions which are based on my experience gained in ~5,000 miles of street use.

I ordered/built my car with RHD, a 438" Windsor making 630hp, an RBT GT40 specific ZF trans w right hand rod shift, and wide bodywork covering 14" wide rear rubber.

The RBT has worked flawlessly, however I don't track the car. For street use, the RBT is fantastic, and using the RH rod shift is one of the great pleasures of driving the car. Highly recommended.

If you are planning 600+ HP, use a dual disc clutch, and definitely go for the wide rear tires. You need them. And a good limited slip diff.

Just my opinions, good luck with your project.

Jack

Looks just like what I'm after. You are correct - I want to build mine. Can you give me some specifics on your engine, clutch, flywheel, bell housing, transmission, driveshafts, etc. Nyla say go for the 14" wheels. All I can find are 12". Can you point me in another direction. What brand and size of tires?

 

[Ron R.]

Arvin,

Powertrain wise, build what you want. Don't listen to the nay-sayers telling you that you shouldn't/can't put anything more than a 400 bhp mill in. Any car that has been decently set up will handle the power fine.

If you're used to a 525 bhp cobra, you'll be fine with 600 in a Gt40. Lots of people are driving around with 600 bhp, just invest in a good transaxle, and resist the urge to drop the clutch and do smoky burnouts.


ps. I don't have a dual clutch, but haven't seen the need. I make 600 bhp, and while I launch hard, I don't drop the clutch. I've never felt any slippage, other than the tires. I have an RBT, and it seems to do just fine on the street, can't comment on track usage either, but it seems to be the "go-to" transaxle on the SPF cars....track and otherwise.

As for the Gulf rear...I don't have them on my car, just the standard "medium" SPF quarters. While I like the wide look, I don't think its a "must have" even with decent horsepower. I've got 10 inch rims running 295s?...and don't feel like I'm on roller skates....but I am geared pretty tall...so...

 

[Jack Dunn]

You can certainly use a single disc clutch. But I like the dual disc clutch because in my experience a single disc that can hold high HP/torque requires significant spring pressure, equaling a heavy clutch pedal. The dual disc clutch on my GT40 (and the dual disc on my Pantera especially) makes for a light clutch pedal which is easy to modulate and is easy on my left knee.

Again, just my opinion. Arvin, I sent you a PM with some of the information you requested.

Jack