10 replies to this topic

[rob mini]

Right then i need help, im really confused here.

Fitted my stage 1 kit which came with a AAA needle and it ran lumpy as hell, so i put my original AAC back in and it ran just as it did before. Ive been told that my '87 city should have a AAU as standard instead of an AAC so im confused. i havnt found too much of an increase in power after fitting the stage 1 kit, 0-60 is around the 17 secs mark and it was around that with the standard manifold aswel. the main reason i am asking is i have the AAA needle in now and leaned the jet right off so its not lumpy ne more but its drinking fuel (£10 lasts 40-60 miles without thrashing lol! if i boot it i can actually see the fuel gague drop!)

please help, cant afford to run this for much longer

rob

[Jordie]

WinSU is a good program which will suggest needles for your engine spec.

[siggy]

Rolling road

Siggy

[rob mini]

would pay the rolling road but im getting a new head in bout 2 months so theres no point shelling out for it twice. looking at winSU the AAU looks like a bit of a compromise between AAC and AAA

rob

[998dave]

Is win SU the funny Excel thing? if so my old boss wrote it.

Believe AAC is the way to go?

Dave

[Jordie]

excel? its a windows program mate, visual basic job or something similar.

[Madmax]

rolling road would sort it out as best as possible, so i guess its up to u whether u get it done or not

[Purple Tom]

it depends i guess on whereabouts in the rev range the performance is suffering? Does it pull well in higher revs and almost 'stop' when you change gear and the revs drop, or seem to fluff at the top end but have good low end power? This means the profile is wrong, and if its the first symptoms is running rich at high revs and lean at low revs, other way round its rich at low revs and lean at high revs. What you need to do is look at winsu and compare the profiles of the needles (AAU, AAA and AAC) all the way down their length, ie, the thinnest part of the needle is when the throttle is wide open and the dashpot is lifted all the way up. Depending on what the symptoms of the running are, you will need a thicker or thinner section here (thinner equals richer - thicker equals leaner). I hope that makes sense, and I hope tthe advice is right, it worked for me anyway.

[rob mini]

erm overall it seems richer all the way through the rev range. its got hardly no low end power at first when the clutch comes out but pulls like a train as the revs rise. i understand how an SU works but just cant set it up. ive read the vizard book aswel and done what it says - still runs like a pig. they are the only 3 needles i have and am unsure of where to buy a new one. got someone who used to race minis for a loada years to have a play with it 2moro night. will let ya know the results.

rob

[rob mini]

anyways just had it checked over by the person who sets my race engines up, its got some fuel economy now which is always nice but we've found the main problem. looks liks ive blown the headgasket - all the plugs were a different colour and the rad had no water pressure at all. compression is still fine though which is good

spose this is a blessing in disguise as it means im gunna have to be building my stage 2 unleaded head back up and have that fitted at the same time

rob

[Dan]

Did you use a compression tester or a leakdown tester, as compression testers only record the peak pressure reached in a cylinder. They don't tell you if all that pressure is leaking straight back out as soon as it builds up. That's why it'll only identify a blown gasket if there's a dirty great hole in it and not a more subtle leak. The leakdown test tells you how great a percentage of the pressure is lost.