[minioneandrew]

Planning on modifying the car slightly:

GTT induction kit (already have)
Janspeed manifold with decat (already have)
Smaller pulley, probably 15%
Bigger intercooler
Bigger injectors
One ball exhaust

Should this be good for about 230bhp? My main fear is fuel consumption, im a poor student, drive to uni every day. So fuel is already quite an issue. Will i notice a big decrease in mpg?
Also thinking possibly about nitrous (as a kind of a weekend toy), the advantage i can see is that ill only be using lots of fuel when the magic button is pressed?
Anyone share some experience with me

[Aberdeen Al]

I think you'll struggle to hit 230bhp with your mods - my MCS is just sitting below 240bhp with my mods.........................my mpg has suffered too

[minioneandrew]

What modifications have you done?
Will my fuel consuption be a lot worse, even if i keep the revs below 2k whilst commuting?
Its either modify the S, or buy a 2nd project car....

[Lucky Dave]

When my car was modded to that level my fuel use was less! but you soon get used to putting your foot down!

[Aberdeen Al]

Quote: Originally Posted by minioneandrew (original)

What modifications have you done?
Will my fuel consuption be a lot worse, even if i keep the revs below 2k whilst commuting?
Its either modify the S, or buy a 2nd project car....

GTT220+ kit
GTT manifold
+1% crank pulley
Schrick cam
450cc injectors
GRS intercooler
63mm throttle body
JCW exhaust
Flowed & ported head

Just recently had an MTH re-map - letting it bed in for now but will get a RR session booked in order to gauge benefits of the re-map.

[Richard Crofts]

I run a 15% and milltek full system/mainifold and alta intake plus tweek bypass valve. My fuel use is about the same as it was stock, I only lost about 2-3mpg

[MINI-Morgan]

I still getting much better fuel consumption with a modified S. 40+mpg on the motorway and 32mpg around town and by town I mean sloooooow!

Al with your mods you should be nearly 250bhp or more.

Andrew you might see worse fuel consumption with the larger injectors too.

[Richard Crofts]

Lucky git ... mine is around the 240 per tank with motorway and below 200 with mixed town and A road. But fitting the pulley made virtually no change as this is pretty much what I was getting before

[ScottyBoy]

Quote: Originally Posted by Richard Crofts (original)

Lucky git ... mine is around the 240 per tank with motorway and below 200 with mixed town and A road. But fitting the pulley made virtually no change as this is pretty much what I was getting before

Mines pretty much the same as yours Richard, sitting at 70MPH on the A1 was about 31MPG and i have a 210 mile trip from home to work and i usually have around 60 mile in the tank when i get back but the petrol light comes on between 40 - 50 mile left.

Around town i average between 190 - 210 per tank full

[minioneandrew]

Aberdeen Al, i would have expected this to be 250 bhp + with that setup, maybe your map will bring it up.
Well that sounds promising, im getting excited about getting this done now.
Are the larger injectors neccesary? My friend did a 17% and nothing else, and he felt it was leaning out top end....
Thanks for the replys

[MINI-Morgan]

Quote: Originally Posted by Richard Crofts (original)

Lucky git ... mine is around the 240 per tank with motorway and below 200 with mixed town and A road. But fitting the pulley made virtually no change as this is pretty much what I was getting before

Wow that is really low.... I noticed a big improvement after Roland had done his work. So I can only say the bypass valve must have improved my consumption and I have the modified inlet plenum that was a big test near 2 years ago now. I can easily cruise at 70mph and get 350+miles from a tank and if im super careful nearly 400miles. Even tested it recently when I drove to Essex which was 230miles and only used just over half a tank to do it And im running 215/40 R17 tyres too. Seems to be back to its old self after a nice intercooler clean, MINI-Mania Manifold and a good oil change

[Aberdeen Al]

Quote: Originally Posted by minioneandrew (original)

Are the larger injectors neccesary?

In a word...............nope! There is absolutely no need to go above 380cc.....................and that comes from a very good source

[Lucky Dave]

Quote: Originally Posted by Aberdeen Al (original)

In a word...............nope! There is absolutely no need to go above 380cc.....................and that comes from a very good source

That depends on your boost.

If your running a high boost pressure the this open the fuel pressure reg and it happened on mine where the pump could not keep up, and I chose bigger injectors and a lower fuel pressure reg instead of a bigger pump.

[Aberdeen Al]

Quote: Originally Posted by Lucky Dave (original)

That depends on your boost.

If your running a high boost pressure the this open the fuel pressure reg and it happened on mine where the pump could not keep up, and I chose bigger injectors and a lower fuel pressure reg instead of a bigger pump.

Was that using the standard (learning) map?

[Lucky Dave]

The map will make no differance to fuel pressure.

But its with a 05 Works map

[Aberdeen Al]

Quote: Originally Posted by Lucky Dave (original)

The map will make no differance to fuel pressure.

I agree but it would adjust the duration of the injectors which is a far better solution.

[1320autos]

Quote: Originally Posted by Lucky Dave (original)

That depends on your boost.

If your running a high boost pressure the this open the fuel pressure reg and it happened on mine where the pump could not keep up, and I chose bigger injectors and a lower fuel pressure reg instead of a bigger pump.

Dave I would suggest you have other issues, we've seen 356bhp on WOT with grip, so thus good G's force forcing the fuel back as well and still reading low 10s air / fuel

[Lucky Dave]

I never said the pump could not supply enough fuel.

Also changing the duration of the injector cycle will not change fuel pressure.

The regulator is a mecanical device controlled by boost pressure.

In an ideal world the fuel pressure should raise as the boost does.

If you raise the boost a lot the fuel reg runs out of head room.

I doubt it can be seen on a car fitted with a 15% pulley.

Im not here to argue about it, Im offering to share my findings which are backed by data.

It became very apparent to me when I fitted a boost gauge next to my fuel pressure gauge, under load the both raise at the same rate, which they have to as the fuel reg is driven by boost pressure.

But at around 16-17 psi the boost was still raising but the fuel pressure stalled and sat at pump pressure, even though the boost was asking for more.

So dispite the injector duration its rate of delivery will change as the injectors supply rate will change with pressure changes.

I hope I have explained correctly?

[minioneandrew]

So with the kind of of boost from a 15% pulley, the standard injectors will be adequate? If so that takes the cost down, just need an intercooler, and the pulley.

[brainycheddar]

I'm running a 15% pulley, and I just installed a CAI, and from what Ican tell, it seems when I push hard I think I'm getting a little knock ( sounds like a someone tappng a screwdriver in there? I'm kinda new too), but it shouldn't be anything that a colder range of plugs can't fix. Other than that, I think that with an oil catch can I'll be knock free...