MicroSquirt.com read only forum (Jan.15,2018)

Hey all. I am finally gettgin some time to possibly attack my MS install again. I still have a bit of work on the car itself before I am ready to fire up nd attempt tuning, but I have a question/concern.

I just had an intake made to better match the heads I have on the motor. With that I also plan to get a matched Cam. NOW, I like a slightly popy/lopey idle sound out of my car. BUT since I have to tune this myself I am concerned that it will both complicate tuning (since it cannot idle smooth ever due to cam) as well as really mess with MS since the vacumm might be jumping around a bit.

Can anyone give me some idead, tips, do's/don'ts on cam?? I will be having the cam custom ground.

5.0L, GT40heads, GT40 lower intake, box upper, 24# injectors, 1.5" full length headers into 2.5" Exh, T5 5spd, in a 2500lb car. MSnS-E (no specific code yet, V3 PCB. My goal is a solid 350 rwhp, high if at all possible.

Larry

Larry,

The main concern will be too have a lobe displacement angle (LDA) that's wide enough to give a reasonable idle vacuum. Something between 112° and 116° ought to do it.

You can select the intake/exhaust lift/duration to get the power you desire. The longer the duration, the wider the LDA will need to be to get a decent idle vacuum.

Lance.

Hey lance, thanks!! I think with that info I can have them grind something up that will be plenty to cause mischief locally!!

If you can "box" the idle point (rpm and map signal change with lope) then you can get a really stable lopey idle.

By box, you may have the idle move through several map rows, but all have same value (or slightly richer with higher map, but marginal).
Same for rpm..

It's a little tricky at first, but if you can tune the rest of the range ok then you should be able to get the idle satisfactory.

Also more likely to be ok with your comment "i like a little bit of a lope".

lamrith,I love a lopey idle too.It would sound so good comming out of my flowmaster mufflers.I have basicly the same engine as u(heads,intake,headers)in my ford ranger.So if u get that cam to work could u give me the specks of cam and #'s for MS.Rigth now I'm pushin 300hd hp.

lamrith,I love a lopey idle too.It would sound so good comming out of my flowmaster mufflers.I have basicly the same engine as u(heads,intake,headers)in my ford ranger.So if u get that cam to work could u give me the specks of cam and #'s for MS.Rigth now I'm pushin 300hd hp.

300hp is nice heh I had 195 when I dynoe'd woth stock cam/intakes/ecu.

Can you give me specs on the cam you used???

The cam I "built" in Desktop Dyno based on my head flow and engine specs are as follows:
INT/EXH
Lift:.520/.520
Dur @ .050: 228/230
Lobe Center:113
Overlap: 3


Desktop estimates 365hp@5500, 388lb/ft@4000

I know it is 512 lift sorry about the rest.why do u want to go with that cam if u can get around 365hp out of yours.

No 365 is an estimate that desktop gives me for the cam I listed. My cam is a stock one.

I would go with the 520 and up .