2.8L M20 9.8:1 stroker build: my 323i reincarnated

[2mAn]

so did the M30 AFM help you pass smog, but isnt helping you make power? Seems backwards, but what do I know.

[betz]

I'm almost certain it's a CPS, CPS wiring, or toothed wheel issue.

This was my thought as well, BUT... it turns out it's not the case.

It's the M30 AFM.

Mr. Squid of the SSSsssssssquid apparently did not note the AFM change although I definitely did tell him. I don't fault him for it, he seems to be kinda overloaded, and plus he's been very helpful and amazing to work with thus far. I would still highly recommend him.

I swapped the AFM's with my friend's 325i and now it's like this. Perfect...

Another retune and I should be good to go. Hopefully the longevity of my engine was not affected...

[Digitalwave]

I'm almost certain it's a CPS, CPS wiring, or toothed wheel issue.

[dadsbmw]

Gonna have to take my probe to this dyno!

[betz]

aw maaaaaan... It's not the ECU, I knew it. At least not a bad ECU...

Here's the issue

Just another quick soul searching montage and I'll have it figured out.

[betz]

That's way too rich as well as what ever ignition / cps issue is killing it

Also the numbers are going to be lower than you probably think but you can't compare to a dynojet anyway as they will be 5-10% lower from what I have seen

The subsequent runs were even richer actually... about .72 Lambda. I have an adjustable FPR now.. not sure if that has anything to do with it (probably not, it's probably the injectors) but I can dial it down a little if need be. Ultimately it will have to be sorted out through tuning though.

Sorry to disappoint 2man but it's just another 173 ECU. I really want to do a full standalone... I've been looking into some other PNP options but nobody seems to be doing it anymore. Might have to sink it all into a MSPNP. Problem is, if I get one, I know the $800 isn't going to be the end of it. It will be more live tuning and dyno time.. which means emptying my wallet yet again :(

[digger]

Here's a better screencap of the best dyno run, since I just received the PDFs. Swapping out ECU and hopefully that will solve the issue.

That's way too rich as well as what ever ignition / cps issue is killing it

Also the numbers are going to be lower than you probably think but you can't compare to a dynojet anyway as they will be 5-10% lower from what I have seen

[2mAn]

Here's a better screencap of the best dyno run, since I just received the PDFs. Swapping out ECU and hopefully that will solve the issue.

What ECU are you swapping in?

[betz]

Here's a better screencap of the best dyno run, since I just received the PDFs. Swapping out ECU and hopefully that will solve the issue.

[sert57]

man seems like deja-vu to my build! Hope your issue is an easier fix though. Torque curve looks really promising, I bet this thing will make a lot of power when you get it sorted out!

[Digitalwave]

Especially with your tach dropping out, I would wager that you're having a CPS signal issue. Check the resistance, check the air gap between the toothed wheel, and pray that it is not a problem in the wiring somewhere. A new metal body CPS is about $140. I've heard a lot of bad things about the cheaper plastic body ones.

[Vic]

Wow! Read the first 5 pages and can’t wait to finish the other 19 tomo on my lunch. Most of the language n parts is gibberish to me right now but you’ve got me wanting to learn what all of this does for the block. Sorry about the 323 but know, it all happens for a reason!


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I've owned 4 xt's (currently own 2) I think the banjo bolt screen issue is due to pure negligence on the owner. I work at a Subaru Dealership, and anytime I've seen a turbo issue it was due to using conventional oil and almost certainly going over the 3750 mileage interval, and not topping off when needed. THESE CARS USE OIL! Check every fill up.

Otherwise I agree with awdbob in every way. OEM parts only for timing belt job... Leave water pump alone as they rarely ever leak! Rear struts are known for blowing out at 100k. kyb Gr2 from an '04 outback work great! Beefier rear swaybar and rear rallitek springs worked well for me too. Cool subie and cool BMW! I'm currently building a stroker for my e30. This thread got me excited!

Btw If you ever want more power in the XT I have a Cobb access port and a catless up pipe that I'm looking to get rid of. Best of luck!

[betz]

Yes, and ... its time to pay the piper.

Lets see the plot

Welp I got good news and bad news.

Good news is nothing blew up and I got a plot.

Bad news, seems like this issue I thought went away has definitely not. I get what kind of seems like a fuel cut at 4700 RPM, the tach shoots down then back up. The motor will continue going but the dyno thinks it's backing off so I didn't get to measure it all the way to 6500+. Since I rarely experienced this on the road, we thought it had to do with the load, which it didn't since the last pull he put it at basically nothing. Will try and sort it out, shouldn't be *too* hard.

Super nice dyno, it seems to measure or estimate crank hp actually. Looks like I'm getting 182 ft*lbs at 3825 RPM and 162 hp where the tach cuts at 4660 RPM. We estimated that peak HP is at least about 200. Edit: see post below for graph

[2mAn]

I marked my calendar



I will share the news with my cousin though I doubt he will give a sh!t

lol like a true forum dad

Yes, and ... its time to pay the piper.

Lets see the plot

[wworm]

lol like a true forum dad