25 replies to this topic

[Chandler93]

Is that on both the standard and 52mm throttle bodies?

[Tom_W]

nice decent air filter, larger metal throttle body and a fuel pressure boost valve is about all my standard ECU will cope with... Obviously a damn good service and a rolling road session will help you to get the most out of your car, but with a standard ECU, you're very limited

Is there a definitive view on rolling roading an MPI? I've searched through various posts on TMF and there have been some that suggest the ECU will automatically adjust to any mods and an RR is a waste of time.

If you do RR an MPI, what do they actually adjust?

I'm about to get my mini back with new SW5 cam, reconned gearbox (with 3.1 FD, central oil pickup and x-pin diff). I'm then going to fit a stage 1 (probably maniflow lcb, with side exit) So I'm trying to workout if its worth taking it for an RR after fitting

[R1minimagic]

With a standard ECU there is not much point in a RR session as nothing can be changed.

The same is largely true for a SPi, if you havent changed the cam, then the ignition is not really affected so you generally come out with the same power etc you went in with.

Its worth getting it on the rollers just to measure the power and torque curves though!

[Chandler93]

Found the throttle stop you mentioned and will be filing it down to allow the Throttle Body to open fully...

The head and rockers are going on tomorrow and hopefully it'll be back out on the road tomorrow afternoon/Friday!

Also going to polish/port the inlet manifold and smooth out the 'lip' where the spacer ring usually sits to hopefully help with airflow.

Edited by Chandler93, 13 March 2013 - 12:39 PM.

[Fast Ivan]

Found the throttle stop you mentioned and will be filing it down to allow the Throttle Body to open fully...

The head and rockers are going on tomorrow and hopefully it'll be back out on the road tomorrow afternoon/Friday!

Also going to polish the inlet manifold and smooth out the 'lip' where the spacer ring usually sits.

sounds like a good plan, the only thing is how are you going to line up the inlet manifold with the rings removed? I think its recommended that you dowel it, but that would require the head to be removed...

[Chandler93]

What do you mean by dowel it?

I was thinking of just using measurements, for example:
Measuring the distance between the edge of the hole and a point on the manifold.
Then measuring the same hole on the head but to a point on the head.
Followed up by some form of mathematics to work out how far the point on the manifold needs to sit away from the point on the head, for it to be lined up...

That should work, right?

[Fast Ivan]

I guess it would, not sure how effective that would be though. I haven't done it yet, but did some research on it a while back and came across this - worth a read and doing some more research.

http://www.theminifo...inlet-manifold/

[Chandler93]

So the principle with that is, place the gasket over the inlet manifold and port them to the same diameter as the ports on the head...
Then drill a hole through the gasket, place it onto the inlet manifold and drill a hole, then do the same on the head in the same position, so when the two join, they're inline?
What if the gasket is misplaced while you're doing this? It would have to be measured most probably to ensure that it was even...

I'll have a word with the guy who's doing the work with me as he knows alot more and he may be able to come up with an idea...
The measuring could work, but it would need to be done with absolute precision, the same goes for porting the inlet manifold, so it matches the ported head, right?

[Fast Ivan]

So the principle with that is, place the gasket over the inlet manifold and port them to the same diameter as the ports on the head...
Then drill a hole through the gasket, place it onto the inlet manifold and drill a hole, then do the same on the head in the same position, so when the two join, they're inline?

thats how i read it.

What if the gasket is misplaced while you're doing this? It would have to be measured most probably to ensure that it was even...

you will need to take care, you only need to mark the hole then centre punch and drill on a pillar drill to ensure some sort of accuracy.

I'll have a word with the guy who's doing the work with me as he knows alot more and he may be able to come up with an idea...
The measuring could work, but it would need to be done with absolute precision, the same goes for porting the inlet manifold, so it matches the ported head, right?

yes it will need to match the head with a high degree of accuracy

Edited by Rob Mac, 13 March 2013 - 02:51 PM.

[Fast Ivan]

edit

Edited by Rob Mac, 13 March 2013 - 02:52 PM.

[Chandler93]

Sounds complicated but simple at the same time.
I'll get my vernier calipers out and apply some precision tomorrow!

The guy who's working with me is quite anal about things like this so it should get done well... Hopefully!

Cheers for the information, you've been a great help!