Experts Help - CSL Airbox - Violent Jerkiness and Bucking Under 2k RPM Under Load

[Cubieman]

I used Pin 16 yes for the ground. 7 for power, 18 for signal.

Ok, so that sounds good, I used the same pins for MAP. There was one member, jbfrancis3 who used pin 16 as IAT ground and had some erratic readings if I recall correctly but I think the consensus was pin 16 is a suitable ground for MAP/IAT.

You can use testo and see the Kassel MAP adapter voltage going up/down up/down etc. during idle as it's positioned in a TB whereas the the voltage of a MAP sensor adapter that ties into the brake boost line is smooth steady line at idle.
But once you press the gas and get the car up to ~1200RPM the Kassel MAP location's voltage smooths out so I don't think that is the issue, just food for thought. You might try the MAP adapter from member COVID-19 is all else fails.
What I just types might not be very coherent as I'm a few drinks in but I made a thread a while back in regards to this, which is likely a non-issue.

[BMWahba]

Ok, so that sounds good, I used the same pins for MAP. There was one member, jbfrancis3 who used pin 16 as IAT ground and had some erratic readings if I recall correctly but I think the consensus was pin 16 is a suitable ground for MAP/IAT.

You can use testo and see the Kassel MAP adapter voltage going up/down up/down etc. during idle as it's positioned in a TB whereas the the voltage of a MAP sensor adapter that ties into the brake boost line is smooth steady line at idle.
But once you press the gas and get the car up to ~1200RPM the Kassel MAP location's voltage smooths out so I don't think that is the issue, just food for thought. You might try the MAP adapter from member COVID-19 is all else fails.
What I just types might not be very coherent as I'm a few drinks in but I made a thread a while back in regards to this, which is likely a non-issue.

Right, but I disconnected the map for some of the testing when I swapped to the stock DME and the same behavior, so I have ruled out the MAP entirely at this point. At least for now.

I need to get the car back to when it was running normally. All of which was before the intake. That’s what I’m failing to understand. If it was vanos related, why is it all of a sudden so much worse with the CSL intake installed, even when back on the stock DME and stock Tune?

[Cubieman]

Right, but I disconnected the map for some of the testing when I swapped to the stock DME and the same behavior, so I have ruled out the MAP entirely at this point. At least for now.

I need to get the car back to when it was running normally. All of which was before the intake. That’s what I’m failing to understand. If it was vanos related, why is it all of a sudden so much worse with the CSL intake installed, even when back on the stock DME and stock Tune?

Those are good questions. I may be misunderstanding but you tried stock dme/tune with the CSL box or with the stock airbox and it STILL bucks?
Another thing I must say if you had Kassel give you their CSL "tune" on a DME you bought from them, it will likely have CSL spec camshaft offsets, these must be changed to US offsets, this is of course assumed you have stock cams. My DME I bought from kassel had US offsets and when I sent my partial off to have someone else look at it they said it was 99% stock CSL fwiw.
I had to use Tunerpro to change the offsets from CSL to US. I wouldn't always throw a code, but it would sometimes, I think it was the intake cam would show an adaption value of 0 in Martyn's software.

Also, which location is your IAT in, stock CSL airbox or elsewhere? If you used the "US" IAT that can be relocated a bit easier it does use different scaling.

[heinzboehmer]

I'm not sure disconnecting the MAP rules it out. If anything, that makes me think that it's not working, as the car is behaving the same with and without it present.

[sc_tr0jan_m3]

Mine did that w the stock csl BIN and two tuners could get rid of it. It wasn’t until I went w Randy from epic that all is fixed now.

Granted at the track I’m hardly ever at 2k rpm.


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[usdmej]

This is the exact hesitation I was always talking about when I used to mention the finnickyness of this mod. Others on the older forum had also literally described it as a bucking bronco like you just did. It wasn't till later on that I realized some people's hesitation issues were a very subtle lag in acceleration

Definitely try to source a section 1 without a crossover.
My hesitation issues were briefly solved by switching from an aftermarket sec2 with no crossover back to stock

[jet_dogg]

Mine did that w the stock csl BIN and two tuners could get rid of it. It wasn’t until I went w Randy from epic that all is fixed now.

Granted at the track I’m hardly ever at 2k rpm.


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Who were those two tuners?

[Onefastsicilian]

I just had my airbox installed with the Kassel dme conversion and a Kassel base map.

the car fuel cut very hard under 3k in any gear especially under load. When I went to Kassel to get a dyno tune, he said the car was super lean and needed a lot of fuel down low that’s why it kept happening.

id recommend getting a tune ASAP! Don’t drive anymoe, just to get tuned that’s it.

[BMWahba]

Those are good questions. I may be misunderstanding but you tried stock dme/tune with the CSL box or with the stock airbox and it STILL bucks?
Another thing I must say if you had Kassel give you their CSL "tune" on a DME you bought from them, it will likely have CSL spec camshaft offsets, these must be changed to US offsets, this is of course assumed you have stock cams. My DME I bought from kassel had US offsets and when I sent my partial off to have someone else look at it they said it was 99% stock CSL fwiw.
I had to use Tunerpro to change the offsets from CSL to US. I wouldn't always throw a code, but it would sometimes, I think it was the intake cam would show an adaption value of 0 in Martyn's software.

Also, which location is your IAT in, stock CSL airbox or elsewhere? If you used the "US" IAT that can be relocated a bit easier it does use different scaling.

I tried the stock DME/Tune with the CSL box still installed. Same behavior. I have not yet pulled the airbox off and gone back to the stock intake, I was hoping to avoid it but I will if I can’t figure this out.

The Kassel tune I did specify to them to let them know I'm running US Spec cams, and again, when Hassan tuned it, I let him know I was running stock cams.

The IAT is located in the little brake duct tube coming from the fog light duct. I drilled a hole into the piping and installed it there right before the snorkel.

[BMWahba]

I'm not sure disconnecting the MAP rules it out. If anything, that makes me think that it's not working, as the car is behaving the same with and without it present.

Good point and something to consider, but even with the stock DME which has no MAP at all? Hassan was informing me how the car runs in pseudo alpha N when there is no MAF or MAP present.

[BMWahba]

Mine did that w the stock csl BIN and two tuners could get rid of it. It wasn’t until I went w Randy from epic that all is fixed now.

Granted at the track I’m hardly ever at 2k rpm.


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Yeah. I would need to get it on a dyno or with an AFR for Hassan to see what is going on and smoothen it out, but part of me wants to make sure there isn't a mechanical failure somewhere, or like others said, something with the section 1 pipe I'm running.

This is the exact hesitation I was always talking about when I used to mention the finnickyness of this mod. Others on the older forum had also literally described it as a bucking bronco like you just did. It wasn't till later on that I realized some people's hesitation issues were a very subtle lag in acceleration

Definitely try to source a section 1 without a crossover.
My hesitation issues were briefly solved by switching from an aftermarket sec2 with no crossover back to stock

Glad I wasn't the only one - the stock section 1 is my next test, I just need to find one locally.

I just had my airbox installed with the Kassel dme conversion and a Kassel base map.

the car fuel cut very hard under 3k in any gear especially under load. When I went to Kassel to get a dyno tune, he said the car was super lean and needed a lot of fuel down low that’s why it kept happening.

id recommend getting a tune ASAP! Don’t drive anymoe, just to get tuned that’s it.

Did you have the same type of bucking when it was lean? I'm tending to think it is way too rich when it's happening. What was your car's setup when it was doing it?

Hassan did mention that he had experience with another S54 swapped e36 which had the same problem, had the section 1 pipe with a crossover, and was able to basically smoothen out the fueling and tune it to fix the bucking that it was causing. I'm not sure if that has any pros/cons versus just swapping to a different midpipe if that is indeed the problem.

[Ragincajun5220]

Sorry to hear about your issues and unfortunately I don’t have much to add, but I do have one question

if the CPI section 1 wasn’t causing issues prior to the airbox install, why would it be causing them now?

[BMWahba]

Sorry to hear about your issues and unfortunately I don’t have much to add, but I do have one question

if the CPI section 1 wasn’t causing issues prior to the airbox install, why would it be causing them now?

My guess is as good as anyone else's.... but.... in theory, the MAF which was on the previous setup would make the adjustments on the fly to account for if the CPI section 1 was causing it to run too rich or lean. Now that there is no MAF, it's running off the stock maps for fueling in that RPM range, despite the various tunes we tested, and the only way to correct it would be via a AFR Gauge to see what is happening in that rpm range.

This is just a theory Hassan suggested and it could very well not be the situation. But, will need to rule it out. I'd rather it be that, than some hard to chase vanos issue or fuel pressure issue.

[sc_tr0jan_m3]

Sooo you “tuned” it without having access to afr data?

I’d start there instead of changing too many variables then you’ll be really chasing your tail.


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[BMWahba]

Sooo you “tuned” it without having access to afr data?

I’d start there instead of changing too many variables then you’ll be really chasing your tail.


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Ha, I laugh as I read this while on the way to the dyno…lol
Let’s see how this goes and will keep you guys updated.