Adjustable fuel pressure regulator

[malc350]

89x2's answer to JT ZR Won's question got me wondering with his question about increased boost...

...are the adjustable fuel pressure regulators you can get (e.g. from Ecklers, TPiS and just about everywhere) of benefit to us TT owners, especially if we're running more boost than stock?

I fitted one to my 93 and thought I perceived a difference when experimenting with varying pressures and tuning "by the seat of my pants!"

Also my 93 had a shrader valve (did I spell that right?) on the fuel rail but my TT looks like it doesn't have - it's all stock as far as I know though?

Anyone had any luck with the adjustable regulator? I guess it would be better (safer!) to run on the rich side?

Merry Christmas everyone.

 

[*89x2*]

Malc, I had my air fuel ratio "sampled" on my B2K and it was "right on the money" w/ factory calibration / stock boost levels. Now if I removed the cats or opened up the exhaust, boost may go slightly higher and therefore, I would have to find more fuel to feed the mix. An adj. fuel reg may help but it would not be a cure to every situation.
I was floored at how quickly Jim@Callaway was able to look into my chip of my SNAT (W/ Wayne) and determine where to make "updates' - all in under 15 minutes
They clued me into some running changes that had been made and I imagine they have stored many "situations" into their data banks and can make an updated ecm chip for anything we could throw their way
Hope this helps. *89x2*

 

[malc350]

Fuel regulators

Thanks 89x2. My car has no cats and I do experience boost higher than 50 under some conditions. A little while ago I was worried about this because I nthought the boost was increasing to potentially dangerous levels. However after a few observations I see that it's never going over 55.

I thought that increasing the fuel pressure may be a good security measure after your reply to the chap regarding Callaway mods the other day.

I have to confess that I feel real disadvantaged owning such an exotic as a Twin Turbo over here (UK). It's very hard to find someone who knows how to work with a C4's electronics over here and I actually do as much as humanly possible myself. I have to rely on intuition and common sense as well as experience and although I pride myself on being able to keep my Corvettes running well (I've owned an 84, 93, and Callaway over the last 6 years and dealt with loads of problems) I'm not an expert the way a lot of you guys are. You seem to be able to take it to a higher level! (compliment!)

I've said it before and I'll say it again-"if it wasn't for you guys there's no way I could contemplate owning my car so far from its original home country!"

Thanks again. Have the best Christmas and new year!
P.S. I'm taking advantage of some of these quiet holiday days and taking the car out for a good blast!

 

[90Callaway]

I would highly recommend an adjustable fuel pressure regulator with no cats and boost over 54hg. Set it to 48psi at idle with the vacuum line disconnected using a pressure gauge. If you really want to make sure your fuel pressure is OK go out for a full throttle run with the pressure gauge taped to the windshield. It should hit about 60 under WOT.

It's cheap insurance against running lean under full throttle high boost situations.

There is no shrader valve at the front of the fuel rail because that's where the secondary injectors tap in. You can hook the fuel pressure gauge to the back of the rail next to the fuel pressure regulator. There should be a metal cap you can remove if it's the same as mine.