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MG MGF Technical - FSE Power Boost Valve

Anyone ever fitted one of these Power Boost Valves to their MGF? Does it give a noticeable increase in power or does it just drink fuel? I've got next months wages spent already!!!

I've got one fitted.

No increase in power at all m8.

After a series of modifications to my car, my car seemed to be struggling for fuel.
Hence why I got the adjustable fuel pressure regulator fitted.

If you are wanting increase power for a similar costing, try a K&N air filter.

paul weatherill

I remember that Dave Livingstone had one of these sitting in his boot at one of our visits to the Emerald Rolling Road. Dave Walker noticed this and explained that it really would not have any discernible benefit. Dave Walker is an engine tuning specialist with tremenous knowledge of the K series engine and its management unit......

Save the cash and buy something else.... better still put it towards a gas flowed head :0) You will need to save a little harder though but it's well worth it.
tim woolcott

The very short answer to that is they're not worth it.

What do they do?

The FSE replaces the standard fuel pressure regulator on the fuel rail. Setting the fuel pressure to a higher-than-standard level means that the fuel injectors can supply more fuel.

Do they give more power?

No. But what they do do is improve throttle responses on throttle transients (ie, you floor the throttle, the engine management system goes into 'open-loop' mode, and the injectors inject more fuel).
Whether your engine can use this extra fuel depends on what else you've done on your engine, but for the standard motor - probably no advantage at all.

Do they effect fuel economy?

Under steady state conditions, no they don't. The fuel is metered according to the Lambda readings (which effectively alters the fueling such that the engine is running at its most efficient). Floor the throttle, and this Lambda feedback is lost, and then, yes, you'll use more fuel.
So the bottom line to this question is 'it depends on how heavy your right foot is'

Good value for money?

No. Money is better invested in an air filter, an exhaust, a replacement manifold etc etc - which are worth getting if you've not already, and your budget will stretch to it (replacement filters start from about 20 quid, and range up to over 400...)

Hope this helps
Rob Bell

Tim is correct. I have an FSE (still not fitted). I was advised that one might be necessary after having the cylinder head ported to ensure enough fuel was reaching the engine. In fact the rolling road run at Emerald showed that my fueling was absolutely fine, even to the peak 172bhp @ 7000rpm.

However, I also heard from Rog Parker, MGOC technical guru and long standing contributor to this board, that the FSE does increase throttle response and may be worth fitting for that reason. Whether you fancy spending £100 for improved throttle response is another issue.

I may still fit it, at some stage, just to see! Alternatively, if anyone wants one unused FSE, just let me know!


"and range up to over 400...)"

We didn't test that one.......!
tim woolcott

It's just a K&N oiled with snake oil ;-)
Will Munns

Carbon fibre ITG sir? Highly polished, and with unaffordiblium finishers?

Suits you sir.


Rob Bell

Hmm. Bloody minefield this modifying lark. A new filter is on the way although I'm just going for a replacement panel filter rather than a K&N. Had one on a car before and the noise was great but fuel economy really suffered even with two cold air feeds providing plenty of cool air. I've discarded the OE air pipes on my F and adapted some cold air ducting to fit the outlet on the existing box and fed it straight down and angled it slightly under the car rather than the rollercoaster route to the back. Noticeably increase in throttle response with this alone and a bit boomier on full throttle so the aftermarket filter will make this even better.

Exhaust is planned as well. Saw a nice one with upswept tailpipes. An "SS" apparently! Just need to track it down. Thinking about a de-cat pipe but dont know how much I'd get shafted by the powers that be if I was pulled over and had an exhaust gas inspection. Obviously I'd stick it back on for the MOT. Anyone else de-cat'd theres?

Famous last words but I don't think I'll do too much performance wise after that! More than quick enough for me (lost it big style in the rain last Friday but managed to avoid lamposts/ cars etc).

Only other mod so far is EBC Greenstuff pads all round. Big improvement and worth it for the cleaner wheels alone!

I'll have to get my ar*e in gear and get along to one of these CSF meetings. Hope to see you there soon!

CRP will not give you anything except for a loud exaust, next obvious bolt on mod in a 4-2-1 manifold, other than that it's head work next (not sure which of these two is more expensive)
Will Munns

The exhaust your talking about is the 'SP' Trevor Taylor job, B&G stock them. They look fantstic and have a nice rasp. However with a CRP it will almost be unbarable though. As Will says, all the CRP will do is save the CAT, there are no performace gains to be had.

Re: Brakes many people have tried the green stuff pads but many have since change to other brands, typically Mintex 1144. Although these still dust up like the OE they have far superior braking qualities, useful if considering future engine and suspension enhancements.

On that note..... other than the K&N, the best perfomance-per-buck, can really be had but sorting out the handling of the car. Suspension is the first port of call. Up-rated shocks, lowering knuckles and correct alignment will do wonders for handling and looks. Then brakes, possible the trophy AP calipers (but these do require trophy wheels) or Mike S big calipers or the Hispec offering. All give huge stopping potential. Then you can start looking at the performance engine mods...A fine pit to throw money into..... (ask me and Kingsley about that one....)

Welcome to bankruptcy
tim woolcott

Will, Headwork is infinitely more expensive, the 4-2-1 is pocket money
tim woolcott

I thought there were power gains to be had for little money (deburring etc.) , but you just had to get carried away ;-)
Will Munns

Removing the weld inside the exhaust manifold is a good start, but then anything else means head off....'that'll be 400 pounds please sir' kerching, kerching, kerching 8-I
tim woolcott

Performing all the work yourself is the only way to keep a cap on the costs of head work - even if you get a guru such as Dave Andews to do the actual porting.

How easy/difficult that would be I don't know, I haven't done it. But given that a number of folks have now DIY-replaced their own head gaskets - which is all the work that is required to replace the head - then it is certainly possible. Who knows, it may be fun! :o)
Rob Bell

> >But given that a number of folks have now DIY-replaced their own head gaskets - which is all the work that is required to replace the head - then it is certainly possible. Who knows, it may be fun! :o)

Unless you've got a VVC. Making the head available for head work requires the VVC mechanism to be stripped off - not something you'd do lightly, even if you were capable of replacing the head gasket yourself!

In the past I have given classes in modifying the K series head to groups of interested parties. Of the 30 or so attendees around eighteen have modifed their own heads successfully. I have also given individual tuition to help and encourage those who wish to do a DIY port. I have also part ported a number of heads to provide an example for people to finish off. Given the right tools and dedication anyone can port a head to 90% as good as any professional.

If their was sufficient interest I could do the same again sometime.

Dave Walker and I tried an FSE on a modifed VVC (similar to Dave Livingstones) because I felt it might be a bit weak having had much head work, however it made absolutely no difference whatosever. Hence Dave's advice..

Dave Andrews

I would not advise routing the cold air pipe under the car if you are keeping a panel filter, the pipe will be prone to sucking up water if you go through a deep puddle and unlike the cone setup there is nowhere for the water to go but into the engine! Safer to reroute the pipe tothe left hand side intake grill, at least then it is at the same height above the road as the standard arrangement.
Jason H
Jason H

Is there really enough of a suction force from the air intake to suck up water??? That seems a bit extreme. I was looking at a close up picture of an uprated cat on the Mike Satur website and the car clearly had a similar setup to mine (although it looked like a Pipercross Viper kit with the pink anodised ends) I'd have to be driving through some serious puddles to draw in water (and contrary to popular belief it doesn't rain that much up here in Scotland)

The only possible problem may be in the winter as I go snowboarding up in the Highlands and I somethimes have to travel on very heavy snow which may block up the bottom of the pipe but I'll worry about that in the winter!

>Is there really enough of a suction force from the air intake to suck up water???

Oh yes indeed, search for 'hydrolic lock', cars driving thru deep puddles (so that the pipe intake is compleatly submereged) is the most common reason for getting hydralic lock and subsequent engine death.
Will Munns

>>If their was sufficient interest I could do the same again sometime.<<

Dave - you betcha I'm interested!!! :o)

Funnily enough I bumped into SteveB on Sunday - and yes, he did plug your tuning expertise! LOL

Anyone else interested in DIY head butchery? :o)
Rob Bell

Rob are you allowed?
I would be interested, but next year (still have to justify fitting this year)
Will Munns

Not in standard class Will, but acceptable in Road Going Modified (will have to read/digest/interpret the regulations).

TBQH I'm more interested in seeing what is involved, and how to do it. Might have a play on my Triumph's cylinder head (which is almost identical to the one you've got on your MG midget at the moment...)

Or obtain a second-hand MPi cylinder head and mess around with that.

Let's see if we can get a collection of MG nutters together for one of Dave's famous 'Knitting Circles' ;o)
Rob Bell

> >Let's see if we can get a collection of MG nutters together for one of Dave's famous 'Knitting Circles' ;o)

OK, I recognise myself :-)

> >obtain a second-hand MPi cylinder head and mess around with that.

With the Master's own work already powering my F, I'd need something to play with as well. Doesn't sound a cheap option though, just for the entertainment value.


Include me in the knitting circle.....

Only problem is I'll have to aquire a caterham or westfield to accommodate the new head.... Oh dear...;o)
tim woolcott

And me too :-)

Scarlet Fever

Well, that's a list of nearly a half dozen of 'interested' folks already - anyone else?

I wonder how many people would be needed to get another knitting circle started?

I'll check with Dave.
Rob Bell

Always fancied knitting.
Paul Nothard

I think I want to move...

Erik, If you move, would you be so kind to take my head along!


I am very happy with the valve, the key is that it must be correctly setup. You have to regulate the pressure using the nut on the valve. Do this by measuring the lambda value :
5000 rpm lambda must be between 0.85 and 0.9, turn the nut until it reaches that value. Note this is a Tip I got from a colleague, I am no expert, take it with a bit of salt, perhaps some experts can correct me if i made wrong statements.

I had it fitted to a 120 mpi, I will now have it fitted to my new 160 trophy. The throttle response is marvellous after fittement, to be sincere and contrary to others in this forum, I think it was worth more then fitting the kn57i and all other modifications I did, it doesn“t give you more HP but it gives you much more NM (especialy at low rpm).

Sorry for the clumsy english.


Dave (Andrews),

As soon as you start a "K-series modifying class" in Holland, please let us know!
Maybe a correspondence course??
Arend Groen

Would we receive a B 'ead after successfully passing the course from the OU of DVA.
tim woolcott

Oooooowwwww! ;oD

Tim! That's terrible! LOL

T - there are circumstances where a Power Boost valve may increase bhp - usually where the existing fuel pressure regulator is maintaining a below-specification fuel line pressure - and perhaps this has been the case for your two cars?

Difficult to confirm in retrospect though.
Rob Bell

Sorry 'bout that..... :-P
tim woolcott

I don't know where you bought your valves (meaning everyone who did and not Rob specificaly) but I bought it in Germany and it was accompagned by a Manual on how to configure it. The valve is definately the same as B&G and all the others (re)sell it.

Perhaps some of you don't know that there is a "nut" on the side on the valve where you can manually alter the pressure of the valve. The more you turn it the more the pressure will build up. (afaik) That's why it is important to measure the lamda value.(afaik)

If you don't configure it (correctly), you will only have the 1,7 time better throttle response, nothing else. Perhaps this might explain why some did experience no gains apart from the Th. response. (imho)

The valve normaly comes preconfigured for your car (don't know about B&G though).


A few specs:
I drove the PVB with the Pipercross aswell as the KN57i kit. (not with the standart filter).

I drove the valve without configuring it and after having it setup correctly, *definately* a difference.

IMHO it was not only a thing of believe. I am quite good at sensing torque. I sensed the difference between 3000RPM and 4000 RPM of the Pipercross and KN57 filter immediately, confirmed by reading (and seeing the powergraphs) afterwards accidentaly on

Of course I could be wrong on the PVB nonetheless. I am baffled nobody else expereinced the benefits.

This time I will have Powergraphs made prior and after PVB fitting (and configuration), I will upload them somewhere and post them here. Let's see what we get for the Trophy.

>>This time I will have Powergraphs made prior and after PVB fitting (and configuration), I will upload them somewhere and post them here.<<

I look forward to seeing these, T :o)
Rob Bell

Would be nice T...

I am considering a PBV myself, as I probably need to change the fuel pressure regulator. Where do you have it configured ?


Hmmm errr. I shouldn't really say this but there is a really decent bloke which some of you may well know off on the Lotus board. His name is Lorne mason and with the much admired work of Dave Andrews and a complete strip down of his K he managed to get 202 bhp. You really have to see this engine it is amazing and it's in a liz. 202bhp in a liz well imagine.

Anyway he has taken the time to video the work including the porting. Know not for one second would I say that it is as good as being there in the flesh. However it along with the workshop manual is a very good guide.

I purchased two videos for 22 pounds and I think that gets you 6 hours of rather enjoyable viewing. Oh my God I am turning into an anorake.
S Laithwaite

Master Mind, Specialist Subject: Anoraks £12.45 to £17.50

Eh ?
S Laithwaite

I know there is a video out there showing you at least how to take the 1.8K series head of and how to put it back on. Found the URL at the time Fabrice had HGF.

This thread was discussed between 18/06/2003 and 24/06/2003

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