[NickM]

Has anyone tried fitting a fuel cut device, HKS FCD, Greddy, Blitz or otherwise to a late model MKIV VVT-i TT (OBDII - Jap Spec).

I've tried the HKS unit, following the instructions to the letter, but I can't get it to work. HKS Europe tell me that there's no reason why it shouldn't.

If anyone can help I'd be very gratefull, I'm completely stumped.

Cheers,

Nick

 

[Drag-On Supra]

The TT never had vvti. Thats on the na supras.

 

[toypro]

"MKIV VVT-i TT (OBDII - Jap Spec)."

My guess is the guy knows what he owns-

What is the trouble you are having with it? I have heard of several others frying a FCD if it is hooked up wrong-I personally don't have any experience with one. Did you have it hooked up incorrectly at any time?

 

[1_MAD_DAWG]

yup

If i remember correctly..the 1999 jap. spec TT supras in japan did have VVT-I

 

[Drag-On Supra]

No Shit? Well, then how much more power does vvti have? Then is it more difficult to find a turbo system that would work for this engine? My bizad.

 

[Grant]

Jap Specs have speed-density from the factory, so who knows how their fuel cut is set up. Probably entirely different from US spec Supras. It would definitely NOT be a good idea to screw with the MAP sensor on a speed-density system

 

[NickM]

Thanks for the replies.

Some of the late Jap spec TT's came with VVT-i, from 1998 on I believe. I didn't know this when I bought my car but the VVT-i is a real PITA when it comes to tuning. There's parts available but you're more limited with what you can do, they're more expensive and nobody, especially in the UK has much experience with them.

Engine wise I have a Hiper exhaust with both cats removed, Super power flow, HKS FMIC, SQV and water injection. I did have a FCON5, GCC and AVCR on the car but after I discovered it was running MAD rich I had a falling out with the tuner and removed them. The fuel cut was in the FCON map so I thought no problem, fit a fuel cut device and run less boost for now until I can afford to change the turbos. Problem is I can't get it to work!!

With both cats removed I'm making around 1.2/1.3bar so I know I'm not getting boost creep. I have NGK plugs rated for the increased boost but I'm swapping these today/tomorrow for some HKS S40i's just to be sure.

I've followed the instructions on the MKIV.COM page and verified these with HKS Europe. It's definitely wired correctly with a good earth and power. HKS tell me the FCD isn't VVT-i specific, you simply wire it in and go. I know it's not favoured in the US but I just wanted to find out if anyone with a TT VVT-i had ever fitted one. I can't find anyone in the UK that has, not to a VVT-i anyway. I don't know if there's something wrong with my car or if you need to mod something else to avoid fuel cut.....?

As for extra power I think the VVT-i gives another 30BHP but I'm not sure. I just wish I didn't have it on my car!!!

Cheers,

Nick

 

[1_MAD_DAWG]

actually

the jap spec VVT-I makes 280 bhp..same as all the previous models..i think the valve timing consumes less fuel at lower rpms..that's it

 

[theman]

MAD-DAWG is right on those specs because of the agreement of the automakers in Japan and their HP limit. But the J-Spec delivery tons of torque even with their under-rated true HP...

As far as the FCD I've never done one, always done the Greddy and they've worked perfectly setting them to 4.29... I'm not sure why the FCD wouldn't work on VVT-i, that shouldn't really make a difference as far as the boost cut is conscerned. Not sure if the colour of the wiring varies but maybe someone at HKS-Japan would be better to talk to about it. The HKS-USA rep should also be able to point you in the right direction as well...

 

[NickM]

I've got a Blitz unit on order so I'll try that when it arrives, if that fails then I'll try a Greddy.

It MUST be possible, I just don't know why the HKS FCD isn't working.

HKS Europe support Jap imports and talking to HKS Japan would mean talking through them. All they say is that it should work and they don't know why it doesn't.

Thanks for your help!