10 replies to this topic

[thegreenhornet]

Hi all, 

 

I've had a look elsewhere on the forum for this, but I haven't been able to find anything that answers the question explicitly. Apologies if someone already has...

 

My Mini has a completely standard 998 A+ engine with a HS4 carb and AAC needle. I've just put on a 1.75" single box Maniflow side exit exhaust, connected to a standard manifold with a Maniflow magic downpipe. It was changed from the standard pea shooter.

 

It sounds lovely and the power seems mostly unaffected at lower revs and part throttle, but at higher revs and/or full throttle it seems to have lost some, most noticeably on motorway slip roads. I never realistically expected to gain any power without upgrading the manifold, and I knew its behaviour would change a bit, but I didn't expect it to lose any power either. After all, it's not like I've strapped a 3" DTM to it.

 

So I'm thinking that it might need a needle change. I know that AAA needles are richer at the top and often used for stage 1 kits, so would I need the same? Or would that only work with a full kit (which I don't want to get for now due to pennies and insurance costs)? I'd change the air filter (although I've just put a new paper one in) but I'd rather keep the manifolds for now. The engine has always liked it a bit rich with the standard exhaust, though.

 

Rolling road seems a bit overkill for a simple exhaust pipe change, no? 

 

Thanks! 

 

Glen 

[Leonrjohnson]

I fitted a MiniSpares performance kit P/N C-STN17 to my standard 998, and this kit contained an AAU needle for the HS4 carb. I just loved the performance, and found that the carb was spot on. I ran this engine for 12 years and it didnt miss a beat. It would keep up with the 1275 cars in our club. :)

[thegreenhornet]

Would an AAU be better than an AAA for mine then? 

 

Would it need holes drilling in the filter housing or the stove pipe and valve thingy taking off? Or just leaving as it is?

[thegreenhornet]

I've been tweaking it this weekend and it seems that making it much richer has done the trick. It now performs well at higher revs and motorway speeds, although I think that it's made it a bit on the rich side at lower speeds and tickover. Then again, better than being too lean I suppose...

[myredmini]

AAU is a good starting point, AAA is too rich, the AAC is far too lean. I have an AAU and it has been re-profiled to suit.

 

I run a 998 A+

Maniflow freeflow manifold

straight through to rear silencer at 1.625" single exit

K&N cone filter

AAU re-profiled needle

Ignition timing at around 12 Degrees btdc

 

Runs very well at this! 

[thegreenhornet]

Thanks :)
Would an AAC still work with a standard air filter and manifolds? Given that I'd rather avoid £60-100 on a rolling road if possible...
Or is there something in between AAC and AAU? Or should I just keep it a bit rich at the bottom end if that's as near as it'll get?

[myredmini]

Im not too sure with standard manifolds. I can safely say I paid £80 for my tune up and it has been the best £80 I have spent!

[thegreenhornet]

Something for th spring maybe, if I can get it set near enough for now :)
I suppose it being a little rich does no harm in winter.

[SuperDeLuxeNick]

I am getting mine on a rolling road on 2nd December and have a very similar set up, so will let you know what is done then to get it running right!

[thegreenhornet]

That'd be great. Thanks :)

[Grimshaw17]

Im not too sure with standard manifolds. I can safely say I paid £80 for my tune up and it has been the best £80 I have spent!

Sorry for the thread hijack, What bhp did it run on the session? Going to have a similar same set up in the new year :)