Rockers upgrade

[bpefi]

This maybe of some interest to people thinking of the mace 25mm spacer, i bought one cheap off an wreck and this is my results after some calibration before and after mods, i have been tuning the MAF myself so i can keep LTFT close to 0

Sorry but I don't know where the link is to what your talking about - I don't know the forum well so I might be missing something

 

[2DIE]

Sorry but I don't know where the link is to what your talking about - I don't know the forum well so I might be missing something

Hes talking about one of these

PERFORMANCE 25mm PLENUM/MANIFOLD SPACER! Holden V6 VS-VY - Mace Engineering Group

I don't understand the tuning part though

 

[The1]

delcohacking.net

The tuning part is simply, The MAF Meter runs from a table in the ecu, so if you make changes to the motor which affect the incoming airflow, more or less through the intake pipe and MAF Meter you will need to recalibrate your MAF Meter tables so it reads correctly. Otherwise your fuelling will be affected. The ecu can compensate for this with BLM tables and using the o2 sensors to change the tables so fuelling is somewhat accurate again, but it doesn't cover everything IDLE and WOT, in my case idle improved with BLM after 25mm spacer but nothing as good as it is now after MAF tuning was done.

 

[bpefi]

delcohacking.net

The tuning part is simply, The MAF Meter runs from a table in the ecu, so if you make changes to the motor which affect the incoming airflow, more or less through the intake pipe and MAF Meter you will need to recalibrate your MAF Meter tables so it reads correctly. Otherwise your fuelling will be affected. The ecu can compensate for this with BLM tables and using the o2 sensors to change the tables so fuelling is somewhat accurate again, but it doesn't cover everything IDLE and WOT, in my case idle improved with BLM after 25mm spacer but nothing as good as it is now after MAF tuning was done.

So whats the chart (dunno why it didn't come up for me the first time I looked - but it does now) saying in a nutshell ??? From what I see your reading htz from MAF & resulting fuel trim - Looks like you have gone up quite a bit with fuel on the lower part of what seems the rev range to get it right....anyone with a spacer is going to be nearly on maximum fuel trim ??? So it will make a fair bit of difference. The short runners is probably why it revs so well - we will lose at top end then if we go with bell mouths - variable manifold would be so nice..

 

[The1]

It's the MAF table the MAF sensor uses, basicly it's the converted readings before and after mods, the first column is MAF hz then the second column is Grams per second of air flow going through the MAF for a stock VS V6, then the next column is after i added pacemaker extractors, 2.5" exhaust and super6 CAI, then the next column is the change in % between stock and when i fitted exhaust and CAI.

So you can see after fitting exhaust and CAI my intake flow dropped by 8.5% in some areas, i dont know why this is but it's what happened, yet i did experience more top end power from the extractors, then with the spacer fitted the airflow gain was 11% down low mostly around idle and just above. There is still 3 and 4% gain to be had with the rest of the table, the spacer has pretty much gotten rid of the hesitation you get when flooring it from idle, the acceleration is alot smoother as well now.

 

[bpefi]

Strange why its dropped across the board with the extractors ???? very strange - you would expect them to go up if not lower revs then certainly at higher - I cant wait until I get some bell mouths - should be very interesting - pity I don't have something like you have to see what the difference will be - I suppose I can record a run with the Carman scan tool & take the figures down manually - once I get the motor going again & then once I do them - I should be able to do it again & compare .... It should smooth things out a bit - might investigate what It would cost getting something made out of a bit of plywood - it would do the same thing & there is no oil pressure going through it - could probably do that myself actually mmmm Things to think about hey....

 

[The1]

yeh well ive seen the same happen on a few vs v6's with pacemakers, as far as looking at fuel trims they all went negative pulling fuel and id say because of less air intake.

I had heard of guys saying years ago it's no good just putting an exhaust on without doing the intake as well, as you can see after the spacer installed the figures are either positive or alot closer to stock than they were with just exhaust, CAI did nothing for flow.

If i had the money id like to see what CAM or Rockers would then do for flow.

 

[soop]

bpefi - Old mate is going to trial my plenum mods to see what the number say over Christmas. Very very keen to see what difference there are, If any.

 

[bpefi]

bpefi - Old mate is going to trial my plenum mods to see what the number say over Christmas. Very very keen to see what difference there are, If any.

I will be looking forward to the results - meantime motor is coming out - interesting to see if I find something

 

[bpefi]

Do not know what to think atm everything is looking good so far with the motor - doesn't look like I will be able to take much off the block the pistons are almost proud of the block now - so looks like the heads will have to cop a fair bit of machining - cant understand this noise - especially when it comes & goes timing chain was good a little bit broken off the tensioner is all I have found wrong - 167000 k & no lip in the bore - no real free play between piston & bore - head gaskets seem very hard - are these Torque to yield head bolts?? They look a bit sad ... Even balance shaft bearings look good - most of these that I have seen run twice engine speed - these are at engine speed only ..??? Valves look set into the head a bit lip is flush with the head just about - so might be new seats & valves yet - dunno what to think - but I will know soon I suppose when bottom end comes out.. cheers Marc