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

[betz]

Ireland Engineering exhaust?

Kinda, it's actually this cheap eBay shit which is virtually identical except maybe some slightly shoddier welds. Sounds almost stock, incredibly nice for the money.

[mr.]

Kinda, it's actually this cheap eBay shit which is virtually identical except maybe some slightly shoddier welds. Sounds almost stock, incredibly nice for the money.

Well damn, just bought an IE Exhaust not too long ago

[2mAn]

I hope this means you will leave the 986 at home and get some mileage on the E30... Im eager to see the dyno. I am still up in the air about what powerplant I want. I think Im going to be less anxious once the car is a 5speed. It seems like when its over 4k rpms it really wakes up

[betz]

I hope this means you will leave the 986 at home and get some mileage on the E30... Im eager to see the dyno. I am still up in the air about what powerplant I want. I think Im going to be less anxious once the car is a 5speed. It seems like when its over 4k rpms it really wakes up

I have been driving it a bit, but I haven't been dailying it. Truth is, I have one more issue I've been trying to sort before I daily.

Fortunately, the dyno might be part of the solution.

Basically I discovered that this subtle -coins in a tin can- type sound I am hearing when the engine is under high load is a mild ping. You'll hear the noise when you lug the engine or if you're just revving it out. Revving it out, you'll hear it for a second at low RPMs and then it will come back for a split second at mid/high-ish RPMs.

However, it'll barely ever ping under normal daily driving, which is good. It's also incredibly mild. I had to make the noise a few times for my mechanic to even hear it. I plan on taking the E30 to work tomorrow.

I have already tried putting in lower temp plugs: the NGK BPR6ES that digger recommended, but it did next to nothing. I think the best solution will be a new tune to back off timing a bit.

I called the dyno place and they do dyno pulls in the morning and are only open weekdays. I think I'll have to set it up and come in work late one of these mornings. Only issue is I'm not sure if should do my dyno pulls without an O2 sensor so I can have their wideband plugged in, or if I should put in a second bung in the exhaust to put their WB into (for AFR readings). Once I figure that out, I'll be setting the appointment.

In other news, I've finally got around to clear coating my Garagistic strut bar and have it installed. Looks nice. Steel = real.



As for you, if you have a healthy M20B25 I would run that, at least for a while. No need to tear it apart unless you are motivated to build a motor. The 5 speed is a much more important addition to your car than better HP or more torque, IMO. Like I said, this build was never for chasing numbers!

[wworm]

next to your boxter?\

cant WAIT to hear this thing with itbs and long tubes.

[betz]

next to your boxter?\

cant WAIT to hear this thing with itbs and long tubes.

Yup that's next to my Boxster. It's been tremendously reliable. Only mod so far is taking out the intake silencer for dat induction noise. Only future mod is a short throw shifter that's waiting to be installed.

I wouldn't hold your breath for the ITBs, but the long tubes will be installed in probably a month or so. In the meantime- I will try and get you a sound clip of it as it sits. I even got an external mic just for the occasion :)

[2mAn]

As for you, if you have a healthy M20B25 I would run that, at least for a while. No need to tear it apart unless you are motivated to build a motor. The 5 speed is a much more important addition to your car than better HP or more torque, IMO. Like I said, this build was never for chasing numbers!

It’s got solid compression numbers but there’s a nasty dip in 2 consecutive cylinders, which I suspect to be a head gasket issue. My “stage 2” plan for the stock motor is the head gasket, which I’ll probably add a cam at the same time. If a cammed 2.5 M20 still isn’t enough then I have like 5 different ideas, and a 2.8L M20 is one of the plans.

I really hope this gets close to 200whp though I know the numbers weren’t your goal. I just feel like M20s haven’t gotten a fair chance to showcase their potential

[betz]

It’s got solid compression numbers but there’s a nasty dip in 2 consecutive cylinders, which I suspect to be a head gasket issue. My “stage 2” plan for the stock motor is the head gasket, which I’ll probably add a cam at the same time. If a cammed 2.5 M20 still isn’t enough then I have like 5 different ideas, and a 2.8L M20 is one of the plans.

I really hope this gets close to 200whp though I know the numbers weren’t your goal. I just feel like M20s haven’t gotten a fair chance to showcase their potential

I see. Well I hope you're getting the jist from my thread here that it wasn't an entirely straightforward process, for tuning at least. When I'm done I'm planning to compile a list of necessary parts for the build and such, hopefully to make it easier for anyone else attempting the build.

It is very doubtful the first dyno will be anywhere close to 200whp. We're talking a motor with far from the ideal tune, on stock intake manifold, throttle body, exhaust, a pretty mild cam, stock valves, with no porting. But as time goes on and I decide to change some of those things.. who knows :D

[2mAn]

I see. Well I hope you're getting the jist from my thread here that it wasn't an entirely straightforward process, for tuning at least. When I'm done I'm planning to compile a list of necessary parts for the build and such, hopefully to make it easier for anyone else attempting the build.

It is very doubtful the first dyno will be anywhere close to 200whp. We're talking a motor with far from the ideal tune, on stock intake manifold, throttle body, exhaust, a pretty mild cam, stock valves, with no porting. But as time goes on and I decide to change some of those things.. who knows :D

Oh yea, I know its not likely to happen without a lot more work... luckily Im well over a year away from any kind of motor swap... you have plenty of time to deal with the headaches ;)

[wworm]

Yup that's next to my Boxster. It's been tremendously reliable. Only mod so far is taking out the intake silencer for dat induction noise. Only future mod is a short throw shifter that's waiting to be installed.

I wouldn't hold your breath for the ITBs, but the long tubes will be installed in probably a month or so. In the meantime- I will try and get you a sound clip of it as it sits. I even got an external mic just for the occasion :)

When I worked at Eason Autoworks in Oakland, it was the only porsche I was allowed to drive, haha. Super fun cars for sure. And man that porsche reliability....kind of amazing. Recently tore down an 84 carrera 3.2 block that had nearly 200k on the clock, most of which was hard canyon/track driving (previous two owners raced motorcycles) and the thing was impeccable.

Either way, this will definitely sound damn good. Looking forward to sound.

and a 2.8L M20 is one of the plans.

I'll be pulling out my 2.7 soon :devil: ;D

[betz]

And man that porsche reliability....kind of amazing.

Right? Subarus had so many issues with their motors, with some of them being absolute dogs. Porsche is just sitting here with higher compression, higher revving, 6 cylinder motors that aren't even meant to be daily driven, but never a head gasket issue.

Anyways. As for my E30, I've decided to try to install a wideband O2. I'm going with an Innovate LC-2. It will let me monitor AFR and simultaneously send corrections to the ECU and I figure I will probably install one eventually so might as well do it now, before the dyno.

[Digitalwave]

The dyno wideband will clip into the tip of the exhaust. It's doubtful they would install one in your mid-pipe in place of the stock O2 sensor.

You will benefit a lot from a proper tune, even on Motronic. But you'll really feel a difference switching to Megasquirt, deleting the AFM, and having a fully proper tune done.

[2mAn]

Did the M30 AFM fit mount directly to the OEM airbox?

[betz]

Did the M30 AFM fit mount directly to the OEM airbox?

Yes, but you can only put 2 screws in without modification. I did two screws on bottom and gasket maker up top, worked just fine. I wedged some silicon plugs between the bottom of the AFM amd the airbox to press it into the top of the airbox where the screws are missing. I plan on modifying the airbox later so I can mount all 4 screws and so no plastic is in the way of the AFM.

Other news- looks like my fuel pressure is all f'd up. I'm going to try a new FPR first and if that doesn't do anything, I'll start looking at the fuel pump.

I teed in a gauge to the fuel supply line. Here's what I saw:
Video

Does this look like a bad FPR? Low pressure, not increasing pressure with RPMs. With vacuum line disconnected it reads almost 3 bar. But with revs it doesn't seem to increase that much.

Better vid of revving pressure

[digger]

Looks almost like a 2.5b reg