Base maps

[datsunboy]

Hi guys,

I am going to help tune a friends car soon, and need some help on ideas for setting up a base tune.

The engine is a CA18DE....standard, BUT it has a Toyota SC14 supercharger on it.

They've been driving it for ages now on a standard CA18DET ecu, but have the timing pulled right back via the CAS so that it doesnt detonate.

So, I would like to set up a base map to give me a starting point. (it will have 2 maps, one will be a stock CA18DE map, then switch to the supercharged map)

I was thinking of starting with a DET map, as that will be roughly ok up top end, but will probably need a bunch taken out of the lower load areas.
How much would you suggest to take out, and in what area's to give me a good place to start from?

[Matt]

at the bottom end you could start with timing values from the CA18DE since that timing map is tuned for higher compression and give you some idea where to start from

Unlike a turbo (which will start boosting from a certain RPM range) the supercharger will start earlier so you would want to be pulling more timing out sooner depending where you noticing boost start. CA18DET top end timing would also need to be pulled also since thats for a low comp engine

[datsunboy]

ok, so a good place to start would be to compare a DE and a DET map, and fill a new map with the lowest of both the standard maps.

So I would have all the lower ign values from the DE map in the low load areas, and the lower ign values from the DET map in the high load areas.

then say take 5-10 deg off the whole map, then tune up from there?

any other suggestions?

[PL]

I can hack something together for you if you like.

Does the pulsing airflow through the blower upset the AFM at all? I would have thought it'd be capable of causing all sorts of problems at idle/low load? I guess as long as you keep the AFM far enough from the blower then it'd help...

PL

[datsunboy]

that'd be great if you could set something up as a base for me!

yeah, this is the second s/c CA18 we've done.....but the other one was done on a DET block, so had lower compression.
the first time at the dyno on the last car, we had a lot of problems with the MAF voltages going up and down all over the place because of the s/c.
We had to abandon that session, and go and move the MAF further away from the s/c and come back to try again (helped a lot). we had to mount the MAF in the inner gaurd to get it far enough away (small engine bay of a Datsun 1200).

I cant remember how this one is set up, but I guess well see as soon as I chuck the logger on it.

[PL]

Yeah, I'd imagine it could be a right pain. May even need to put some sort of reservior between blower and AFM to help smooth the airflow.

I suspect the std AFM (or SR20 AFM) would probably handle it better than the R32/R33/Z32 types as they are designed to handle reversion better.

I'll do some playing with a CA18 map tonight...

PL

[PL]

I had a bit of a play with some CA maps last night. Decided to start with a DET map. I'm assuming you'll be using 370cc inj from the DET, so K constant from DET is the go.

I've adjusted fuel and IGN maps to roughly where I think a good starting point would be. I have no idea how close this would be, but if I was tuning a DE with a blower on it this is what I'd start with.

PL

[datsunboy]

excellent thanks!

I will have a look over it, and then give it a go and see how close it is, probably next weekend.
was hoping to do it this weekend, but I have to head up to Auckland to crew for a mates "modified" in the NZ modified champs.