22 replies to this topic

[welshdan]

hi, i know it has been said by various people that fitting a larger throttle body to an mpi mini doesnt make a difference.

however, i bought an alloy dellorto 52 mm one second hand, and have just finished moding it for fit a mini. the standard plastic one was sticking sometimes.

the car was standard, but modified standard throttle body to open to the full 90 degrees, and later fitted a k and n induction kit. i also tightened up the throttle linkage cable. though none of these mods made a huge improvement on their own, each made the car feel progressively better to drive. as it is now it feels much more responsive, and feels as though there is a fair bit more tourqe than before.

i am working away for a week from tomorrow, though in the next few weeks i will change the throttle body over and see if there is a difference. although im not expecting huge gains, i would expect some sort of improvement.

is there anything i can do about the injecters, eg fitting larger ones?

hopefully in the future i will be porting and polishing a standard mpi head, cleaning up the chambers, regrinding the valves in, and having it skimmed to raise the cr

will also be fitting an inlet manifold which i have already ported and polished, as well as some high lift rockers. can anyone sugest anything else i can do to modify my engine, bolt on wise?

many thanks

[Cian 'the pain' MPI]

Ive done the same as yourself, but ive also put a decat pipe on and fitted a fuel pressure regulator which was a lot easier to fit than i first thought

As you said on thier own performance is neglegible but when mixed with a good stage one package the results are great

[perryman1001]

does the decat pipe make it much louder or change the responsiveness? cheers

[Cian 'the pain' MPI]

Yes it does make a difference in the loudness , the cat does act as a silencer. And with a decate pipe its easy to take out and put the cat back in

[perryman1001]

what about the responsiveness of the engine...does it affect it? Cheers 4 getting back to me

[sir Jake the brit]

what about the responsiveness of the engine...does it affect it? Cheers 4 getting back to me

the de-cat has been shown to only give 1 BHP!!!! so i wouldnt bother with faffing about!!!! for swapping at mot times etc!!!!

[perryman1001]

already fitted it now and there is more of a difference than expected! and sounds amazing! also doesnt really about MOT as a mate will stick it through for me

[nicksuth]

Ive done the same as yourself, but ive also put a decat pipe on and fitted a fuel pressure regulator which was a lot easier to fit than i first thought

As you said on thier own performance is neglegible but when mixed with a good stage one package the results are great

I am also carrying out the same mods (de-cat pipe, 52mm throttle body, new lcb, reconned injectors, ALL sensors replaced and bought the Power Boost Regulator) on my MPi but not so much to improve performance, more to try and improve things as I have a bit of a msifire and hesitation at light throttle.

Do you have any photos of you engine bay showing the installation of the PBV? the instructions appear a little vague!!!

Also, is there a port to fit a pressure gauge on the PBV?

Cheers

Nick

[sir Jake the brit]

already fitted it now and there is more of a difference than expected! and sounds amazing! also doesnt really about MOT as a mate will stick it through for me

whats your full spec????
what power do you think your achieving?????

i havent bothered with the de-cat, tho if you say it works then i may think about pratting around with it, my spec is alot past just minor breathing mods so it may help even more?????!!
but not befor i get a new ecu

by sound amazing do you mean really loud?? what exhaust you got on??

cheers

[perryman1001]

different exhaust lol i'll have to upload a pic and normal when driving casually but when you put your foot down it sounds awesome especially after 3000 rpm gets loud then!

and full spec im not sure, when i got it it was overbored to 1299cc. dont know any details on this its just got ramair filter, polished inlet manifold, maniflow LCB exhaust manifold, different final drive (not sure what, was also done when got the car), 52 mm throttle body erm... lol think thats it engine wise atm but a new head and rockers is scheduled next year

and i would of said it would help...my fuel economy hasnt really changed when town driving and it picks up better higher in the rev range in my opinion...

hope this helps

edit to add zorst pic:

Edited by perryman1001, 17 December 2008 - 04:59 PM.

[nicksuth]

..................... are you sure thats not for a Suburu Impreza WRC???? Be careful it doesn't suck any dogs. cats and small children in!!!!!!

[Sprocket]

DEAR GOD

[perryman1001]

everyone says that but it really isn't that loud!

I had a twin 3" DTM before and this is quieter and on tick over it sounds like a normal sports exhaust, only gets loud when the lead foot is dropped lol

it also tucks right up under the body so don't notice it as much as a normal one

[sir Jake the brit]

3" what the hell!! lol
impreza's and evo's need that!!!

i have a 220bhp cooper S and i wouldn't want a tailpipe that big!!!!
my proper mini works has the john cooper works exhaust on it (twin 1'1/4) and thats cute!!!

jap stylee!!!

personally i'd have fitted the sexy playmini carbon exhaust, but each to there own i guess!!!!


1299???? do you mean 1293??? +0.020 bore???

unless it has a slightly offset crank???

[perryman1001]

probably is 1293, there is literally no details on it :| its gonna get stripped down next year so i can find out what it is actually running

and yeh 3" was big and loud lol and i was going to get the carbon one but then found this one so decided to get it

whats your full spec then? I seem to find a head i want and then change my mind so not sure now what to get lol was going morspeed but heard a lot of bad things so not gonna now