Adjustable fuel pressure regulator

[TVRTASMIN]

Anybody know of an adjustable fuel pressure regulator suitable for the 2.5 ?

[E30Adam]

Why do you need to adjust your fuel pressure?

[TVRTASMIN]

You tend to find that trying different fuel pressures above standard do give power gains not just banging on one that is pre-set.
I used a weber item on my 5.2 Litre TVR Chimaera and a difference in power output was noticed on the dyno if you went above a certain pressure.
Courtenay Motorsport who tune Vauxhalls fit a 4 Bar regulator to the 3.0 litre V6.
Top Boss Performance do the same thing with the Cosworth V6.

[E30Adam]

You tend to find that trying different fuel pressures above standard do give power gains not just banging on one that is pre-set.
I used a weber item on my 5.2 Litre TVR Chimaera and a difference in power output was noticed on the dyno if you went above a certain pressure.
Courtenay Motorsport who tune Vauxhalls fit a 4 Bar regulator to the 3.0 litre V6.
Top Boss Performance do the same thing with the Cosworth V6.

Well fitting one to an E30 is a pointless exercise because you don't need one unless you purposely want your car to chronically overfuel. I have a stroked 2.8 M20 in mine with a MAF conversion and a whole bundle of other mods and raising the fuel pressure still isn't necessary.

Also Alpina and Hartge stick to the stock regulators. The only time I would suggest fiting one to an E30 is if you do the M30 AFM conversion where the pressure needs to be set to about 3.5 bar. THis setup takes an age of fiddling about to get it spot on when there are other routes available which are far better.

If you do insist on purchasing one though, steer well clear of the FSE Power Boost Valve. Whoever owned my car prior to me fitted one and it was tweaked on a dyno and found to give best results at stock pressure.

The valve caused me 2 engine fires, the second because I refused to believe that it was the FSE valve that caused the first, thankfully I was at home the first time so was able to extinguish it and the second time I'd prepared myself with a fire extinguisher.

I've heard a few other horror stories about FSE too and know of one other person who had the same thing happen.

[TVRTASMIN]

Thanks Adam you seem to have a lot of experience with the E30 six.
I'll probably run a few things past you sometime to see what you think if you don't mind.
I agree on the FSE item but this varies the pressure over base setting under vacuum, i'm talking about one that will adjust to an optimum pressure and has no vacuum tak-off. So this might only be a couple of psi over standard.
I think i have a 2.5 Bar regulator as standard did the later E30 2.5's change to 3.0 Bar?

Regards

Ian

[E30Adam]

Thanks Adam you seem to have a lot of experience with the E30 six.
I'll probably run a few things past you sometime to see what you think if you don't mind.
I agree on the FSE item but this varies the pressure over base setting under vacuum, i'm talking about one that will adjust to an optimum pressure and has no vacuum tak-off. So this might only be a couple of psi over standard.
I think i have a 2.5 Bar regulator as standard did the later E30 2.5's change to 3.0 Bar?

Regards

Ian

Sure Ian, any questions please fire them my way and I'll do my best to help.

I'm not sure how you'd go about fitting a fpr without a vacuum takeoff, I guess you'd just plug the output in the inlet manifold. I've not had any experience with this particular type of regulator so wouldn't like to say if it would make any improvements. My initial thoughts would be that no difference would be made unless you were replacing the injectors for higher flow items. I still don't think one is necessary until you start stroking it to about 3.0 litres (which is about the limit for an M20) or turboing it but then you'd need a rising rate fpr.

There was infact a 2.5 bar regulator used on the M20's but I believe this was used on auto's. If you've got a 2.5 bar regulator then I would probably suggest replacing for the 3.0 bar item which is more commonly found on the M20.

[TVRTASMIN]

It is a 3 Bar regulator i've got on. I work in old units so it is 43.5 psi.

Another question. what is the difference between the 'L' shaped IACV and the 'T' shaped one. Both are 3 wire Motronic? 0 0280 140 509 and 0 280 140 524 respectively.

[E30Adam]

It is a 3 Bar regulator i've got on. I work in old units so it is 43.5 psi.

Another question. what is the difference between the 'L' shaped IACV and the 'T' shaped one. Both are 3 wire Motronic? 0 0280 140 509 and 0 280 140 524 respectively.

The difference in the 2 ICV's is just the design, IIRC the early cars generally had the L shaped and the later had the T shaped. You need to have the correct rubber elbow for your ICV though.

There are actually 2 variations of the ICV but I'm unsure if these variations correspond to a particular design, one has 3 pins and the other has 2. They effectively perform the same job but have slightly differing internals.