power boost valve ??

[andy390se]

anybody put one on their car?
sounds like a good mod for the money.
if so are they easy to fit?
ta andy.

[dickymint]

On a 350 I would say definately. On a 390 not so sure. Easy peasy to fit so give it a go. I would like to hear Shpubs take it now though.

[adam quantrill]

Otherwise known as a rising rate regulator.

Yeah I have on on the 350i, easy to fit, but you might want to use a decent fuel pressure gauge to set it up properly (some of them come with a built in gauge). They are handy to adjust the fuel pressure to suit the engine.

[badredwedge]

I put one on the 400, very easy to fit but you do need to get the pressure right and be sure you fuel lines are up to it, SH does have a section in the Bible on such things. I got mine from Demon tweeks, about £100 complete. I think Rev fitted one to the SEAC

[shpub]

dickymint said:

On a 350 I would say definately. On a 390 not so sure. Easy peasy to fit so give it a go. I would like to hear Shpubs take it now though.

The 390s had them pretty much as standard. Yes good improvement. The 520 still has one albeit it is now hooked into the supercharger system so that as the boost pressure goes up, the fuel pressure also increases to around the 50 psi mark. Currently. The DTA ECU also provides a similar boost based on the throttle angles and manifold pressure. When the throttle is floored, I can hear both pumps going into overdrive to keep up!

[andy390se]

thanks guys still a bit in the dark shpub says the 390 had one as standard so is it worth doing?
quotes like make sure your fuel lines can take the pressure scare me!
still dont know what to do?

[350zwelgje]

Normally the fuel lines are up to the pressure. But if you set the pressure high (like 5 bar instead of 2.something...), it could show that old lines are not up to it. Think standard petrol fuel lines are ok for up to 7 bar. So if lines ok (replaced recently, not over 10 years old), no worries about that.
Probably the 390 has a regulator with at least a higher set pressure. Rising rate, has a different ratio depending on vacuum and helps during accelaration.
I have one on the 350i, with a gauge and have to reset regularly, and it seems that that brand is notorious for it... The thing costs like 60 pounds and 15 minutes to install. Re-adjusting is like 10 seconds...

So not too bad to just have a go to try it out.

Rob

[GreenV8S]

I've heard people say one of the well-known brands of rising rate regulator is prone to going soft with age and losing pressure. So if you fit one, I'd suggest you check the fuel pressure as part of the annual service.

The effect of these is to make the engine run richer (compared to the original flat rate regulator) when you open the throttle. If the engine was running lean before, this might be an improvement. But if it wasn't lean, adding more fuel is throwing power away - and money.

[wedg1e]

AFAIK the 390SEs FPR was NOT rising-rate: it IS adjustable but all it does when running is lower the fuel pressure according to vacuum, it does NOT increase it (above the set point).

[andy390se]

so you guys reckon put one on i have new fuel pump and fuel lines, allready done when i bought car in oct so hopefully no probs there. from reading replys most of you think they are a good idea and do work so i will be investing and letting you know how it goes.

[rev-erend]

badredwedge said:

I put one on the 400, very easy to fit but you do need to get the pressure right and be sure you fuel lines are up to it, SH does have a section in the Bible on such things. I got mine from Demon tweeks, about £100 complete. I think Rev fitted one to the SEAC

No - mine is not rising rate..

Just a new adjustable regulator - with gauge (only fitted to check pressure).

[campbell]

I have a V8 rover FSE power boost valve for sale if any one is looking for one, it has been used and done less than 1000 miles and i have the origianal box too.
If you email me i know they cost over £85 quid from demon tweeks mine will be a bit less.
And if you need help fitting i can give pics of instalation.

Cheers

Campbell

[badredwedge]

rev-erend said:

No - mine is not rising rate..

Just a new adjustable regulator - with gauge (only fitted to check pressure).

Sorry Rev, getting confused between a Rising rate and adjustable, the one I fitted to the 400 was adjustable.


The gauge screews into the top to check pressure

[adam quantrill]

Mine is rising rate _and_ it's adjuestable. Yes, you have to check the pressure is OK every so often, I usually have to turn it down a bit for the MOT to get the CO down, then up again for road use.

[rev-erend]

THe old flapper system is OK with rising rate and the later hotwire / 14 CUX systems do not need rising rate as the system handles acceleration enrichment in a different manner.

[350zwelgje]

Be prepared that:
- if used for driving hard, it will use more fuel. Especially on track days as I discovered (12 miles to the gallon anyone....). Wedge probably thinking it is a younger brother of Steve Heath's car.
- Petrol gauge becomes sort of an econometer - while accelerating the indication goes lower (with me even negative!).
- Don't overdo the pressure: 2.75 bar (don't know psi for this)seems to be the correct setting, and works fine for me. Think over 3.something bar the injectors start to weep (=pressure is so high that the injector is letting petrol through).

But you will enjoy the experience.
To take full use, also check the overrun valve.

As said before, all can be found in the bible.

Rob