Has anyone on here had any experience tuning the Evo to run up Pikes Peak, info like does the ecu/maf cope with the elevation change, AFRs and boost control.
Any info would be much appreciated.

 

Direct PSI would be beneficial in this situation. MAF....no problem...at least I would think, especially after hearing about elevation woes with the current SD. Maybe eve n run full time open loop for something like this. Just some ideas, I could be wrong.

 

Not much closed loop going on at pikes peak.

I would tune with the highest elevation in the back of your mind, and for the mid elevation to meet in the middle.

It's going to go rich up there. If you have a way of messing with compensation to work to your advantage, then do it.

- Bryan

 

thanks guys, yes I was thinking of messing with the baro compensation, and the cranking IPW.
This will be for an Evo8 running E85, probably 1000cc injectors but the choice of units has not been made yet.

 

I'm jealous PPIHC looks so awesome, but I don't have the ***** for that type of thing (well, the pocketbook at least).

I would think you would want to stick with load based boost, otherwise your boost targets might go crazy, and your map will be all over the load areas as you climb the mountain. MAF might be a good idea just to make sure you don't stall or something if you need to clutch in off the gas, but I don't have much experience with crazy elevation changes like that. I would think that without baro SD is going to be out of the question.

I wonder if ACP or that other couple that runs it would give you any tips? I can't see why not if you are not competing against them. If not, it might not hurt to contact AMS since they tune for both of them.

 

^agree with you there fosty on sticking with MAF and load based boost control.
The car already has aftermarket boost control, but I will work-up a a fallback strategy using the ECU with temp and baro corrected boost control. Hopefully that should work ok but will require adjustment on the early practice days. Along with everything else I suppose.

 

I have tuned a couple cars for Pikes Peak.

They were speed density cars all of them on stand alones. It took a little time but once you get a solid baro comp chart setup its not too bad. High temps is trickier with larger turbos and no air lol.

Mitch

 

What about setting a trigger point and coding the ECU to allow live map switching? For example...You start the climb in one map....as altitude starts to increase and power starts to diminish you can flip a switch and instantly get that power back for the rest of the climb because of the tune.

I agree that a MAF based system with load based boost control....this will be much easier to compensate for the change in altitude.

Possibly throw in a rheostat to control the fuel pressure....as the climb continues and the air gets thin you can dial back the fuel by lowering fuel pressure? This might be able to be done with the current fuel pressure solenoid with proper code.

Just a couple ideas.

I grew up in Colorado. Drag racing was an art back in the day with V8 and Carbs. You had to keep multiple sets of jets on hand to compensate for any given day.

Paul

 

I have only done testing with the MAF to 5800' but I can tell you that cruising at sea level I normally see something like 101-102 kpa, under light load climbing it will drop 3 or 4 kpa. At 4k feet this was down an additional 10% as registered by the MAF. At 5800 it was another 3-5% depending on how you want to interpret the logs.

I also vote for a stock MAF with a pulled WG line probably.

I like power though

 

Thanks guys, certainly something to think about.
JB, did you AFRs change much ? Also, what do you mean by "pulled WG line"?

 

I think he means free wheeling (aka no boost control and lots of good fuel )

 

On my drive out from WA to FL, I hit some pretty decent elevation changes, however I wasn't logging anything. I can tell you that the car was reacting dfferently at higher elevations with regards to boost control, and relative pressure, It was defnitely harder for me to "cruise" without getting BOV flutter.

Pulled wastegate line means no boost control...

 

At those elevations the AFRs were consistent with sea level. Still half the height your starting point is on Pikes Peak I think.

As was pointed out, pulled wastegate line is the same as freeboosting.

 

I have logged AFR's and barometric pressure going from around 6-9k feet and AFR's remained consistent. This was on my car which is still MAF based.

 

I had very wonky AFR going from 2,000' to 9,000' running SD on my car. AFR went a point and a half richer all over the fueling map. For Pikes Peak, you'd be starting at 9,300' and finishing at 14,000'. Talk about thin air.