Have the attached TVR with an 02 - 04 spec LS6 in it.

It has non fly-by-wire 85mm MAF. These TVR's traditionally have very stiff throttle springing (no traction control crap) so that you have to "push" to get the power and when you let off the gas they spring back fast and give you that instant engine braking.

I get this weird feeling when really rolling on 120 and up mph that when I lift off I am not getting the instant retardation I should be - when I look and consciously feel what my right foot is happening when lifting off it is getting instantly released but just not as quick (or as hard!) as I'd like (still feels like a Saturn Rocket is attached for a spit second longer than it should - Scarey! whn up round 150mph).

I think the return spring on the throttle body is a bit weak and the
feeling that it is sticking open (or rather not snapping shut as hard as the last engine having a much stronger returner spring on the throttle. I am thinking of putting on a spring in the foot well to pull the throttle shut harder than the one on the TB.

Does this sound like something you guys mighthave heardof b4?

Can you get stronger TB return springs?

Or should I fit the (in foot well) additional return spring.

Thanks in advance.

Pic's at this years Le mans watching the Vette Cream the Astons.
http://www.pistonheads.com/gassing/p...&memberId=7660

 

It's a big v8. No matter what it's going to have the "saturn rocket" feel to it. It's because it ingests so much air that after you close the TB it still has air in the plenum.

 

Spooky - the car had a 5.0 V8 before!, so I know what a biggish V8 is like. I think it should snap shut faster - thing thing gets to STUPID speeds alot faster than an F-body as only 2450kg and over 400bhp.

 

You need a pedal return spring and check whether the throttle cable is good and free and not too sharply curved at any point. Disconnect the TC and open the TB butterfly. It should snap back sharply when you let go.
By the way I think you must mean 2450 lbs NOT Kgs unless it's a bus.

 

Beautiful car! In the second picture, you look like an American: getting into the left side of the car and wondering where the steering wheel is! I've done that before when travelling in Australia (where I'll be next month).

I think GM engines often have weak throttle return springs. Supplementing it with a stiff external spring will probably solve the problem.

 

There is nothing weak about the LS TB return spring.

 

 

Mate in Picture not me. The T70 must be a great drive - in UK / Road legal? An yep lbs not kg!

 

Yep. Soon to be road legal(ish) in the UK. Not much of a summer though.