2.2PR is 18psi. A PR of 1 is 15psi (100kpa).
The edge of the compressor map is the far right edge which represents the maximum flow rate.
Low 60% is the percentage efficiency of the compressor. Its in the efficiency island thats far from the center (peak efficiency). When you are in the lower efficiency range for the compressor you will be generating more heat (higher inlet temps).
Thank you all!
Might seem dumb, but how do you know you are flowing 55lb of air? I see how that indicates 60% at 2.2PR.
Last edited by BadBoostedBmwM3; 11-27-2016 at 11:22 PM.
This is my signature....
Unless you have a turbine speed sensor, you are really just guessing where you are on the map. If you have a mass airflow sensor you can get a rough estimate at the PR you are running where you are on the map. In truth few people in the hobby field have the ability to map it correctly.
Yeah, that works too. From power level you can work back to determine airflow.
Long time no post!
So, at a recent dyno night, I set my closed loop boost control to run 22psi - ramping up. It topped out at 19psi and went no higher.
My intake temps hit over 50degC on a night where the ambient was about 5degC. My AIT was nearly double what my buddy with a 6262 hanging off an M50B25 hit and he ran around 25psi.
Two things, or maybe three....
Are those 450x300x76 ebay FMICS all the same?
Is my S256 compressor just pegged out and falling off the RHS of the map?
Is the 9psi spring in my Turbosmart WG just too light for 22psi?
Something needs fixing here, and the FMIC would be a good start, but the boost....what tha?
1989 E30 - M50B28 Turbo - ZF 8 Speed
Just a note my s52 made 463whp at 13 psi and didn't make any more at 20 psi with a s256sx. Poor guy was out of air.
We have essentially the same FMIC i think? size anyway. Mine was listed as bar & plate however; i never even looked/verified. Definitely interesting the difference in our IATs though.
I also thought about it more. Im not 100% convinced you might be out of spring. I have 11psi of spring in my and can get over 30 out of them, the creeping RSI manifold probably accounts for some of that too though. Your WG placement is far more prevalent/ideal though so it could be possible.
That's what I fear...the compressor is outta puff! It holds 18psi all day but the IAT is hot.
GTX3582 Gen 2, perhaps? Got a spare $3K Or maybe S363SX-E with a 1.00AR TS exhaust housing?
- - - Updated - - -
We do have the same FMIC as far as origin and size goes, but who knows about the innards of it. 10 years or so between their purchase date as well.
I'll chuck a different spring into the WG and see how it goes, but I suspect Rajicase is correct in that the compressor is done! Then again, if that cheesy ass FMIC is sticking a cork up the compressors bum, that aint gunna help the cause.
1989 E30 - M50B28 Turbo - ZF 8 Speed
I stepped up to a s366sxe on my s52 and absolutely love it. I am unbelievably happy with it, especially for the ridiculous price.
I think I paid $708 shipped from thmotorsports.
Woah! What? $708?? That's theft!
Price check on SXE363 please, Mr Thayer!
Your S52 will have a bit more huff'n'puff on the turbine than my lowly M50B28 stock motor though. As it is, I have a turbo setup that really comes alive at 3000rpm and tapers as it approaches 6500. I'm worried that an SXE36- unit will give me a sad face if it sucks balls around town. We aint all freeways n shxt over here.
Check it....ramping bewst!
dyno.jpg
1989 E30 - M50B28 Turbo - ZF 8 Speed
Get urself a good ole Bob Wagner in there
328i Sedan Twin s366's, 6.0LS, TH400, MS3 Ultimate
9.20 at 150 on 22psi
All intercoolers are not created equal. If you look around you will find some back to back tests of eBay intercooler cores vs good ones and the difference can be staggering. Turbo is definitely about maxed out
Yeah, sadly, I think it is. I figured when I saw the HP figures at 18psi, combined with the IAT's, that it had virtually nothing left in it. That hunch was right I guess.
Picking the right intercooler for this thing is a PITA! Measured up, a 450x450x76 core would work out well, but just try and find this size! The closest I can can get HDI GT2440 tube and fin.
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Fixed it weeks ago ;-) And it was only rich in the last 1000rpm, not the entire map.
1989 E30 - M50B28 Turbo - ZF 8 Speed
Well, it was bound to happen eventually.....I broke something in the LHS drive shaft!
After a lazy 1st and 2nd gear, I went to 3rd and about 60% throttle. At about 4000rpm, the RS-RRs crossed over a road defect which had about a 1" bump upwards forming approx a 4 meter 'table top' section. Of course, it zapped straight into total traction loss and hit the limiter. At the other side of the 'table top', it dropped into a depression which was followed up by a rise up again. The RS-RRs gripped, and BANG! No drive.
I pulled off the road and carefully sussed it out, but the car wouldn't move and only returned a light grumble noise from the rear end. I'm surprised that the LSD wouldn't budge the car, but I dunno.
The LHS DS turns, but the wheel does not. The CV outer cage is intact, so I'm thinking either DS spline or stub axle spine has let go, or the stub axle has snapped. If it was a CV I'd guess the noise would be horrific.
Oh well, this failure was well overdue, so now it's time to install the Z3M rear end gathering dust in my shed.
1989 E30 - M50B28 Turbo - ZF 8 Speed
Yep, there's the problem.....
26971853_10155162809048091_1405341109_o.jpg
1989 E30 - M50B28 Turbo - ZF 8 Speed
That looks nasty!
Out of interest on the intake temps, where did you say the sensor was located, close to IC outlet or closer to TB or in the mani? When I was running the sensor in the mani I was seeing temps of over 50C on pulls, once I moved it to just post the IC, so pre throttle body, my intake temps dropped dramatically so I was seeing in the region of 20C on pulls. Maybe the sensor in its current location is getting heat soaked?
Yeah, it went crunch! But being realistic about it, it was only a matter of time before a CV broke, and I'm surprised I've not busted several of them already. Poor little things started out life having to cope with the 'savage' power of an M40B18 auto, then along comes M50B28T!
The temp sensor is threaded into the plastic intake plenum and is an Autronic 'grain of rice' type - very quick reacting. With sensors that are poorly located - such as an uninsulated intake pipe - they can be reading the hot pipe. In that case, you'll likely see the temp drop under boost, but I'm seeing the temp rise dramatically.
I'm pretty sure that the turbo is topped out, and these temps (combined with a shitty FMIC) are the reason for the temps.
I've been checking out MATCHBOT
An S300SX-E ought to be sweet! But I'll need a TS mani or it'll most likely suck. Or, maybe an auto with a high stall!
1989 E30 - M50B28 Turbo - ZF 8 Speed
Dudes! Long time no post from me, but the e30 is finally on the road again!
Since breaking some sh*t, it has got a few upgrades:
Hub adapters with e36/46 bearing hubs
Custom Nutzy design caliper bracket
Wilwood 4 pot calipers
325mm e46 front rotors
E32 25mm MC
Z3M rear end
315mm rear Z3M rotors
Rear camber/toe eccentrics
BMW Style 68 rims
The brakes were a fun project that required quite a bit of the old grey matter injected into it. Working out the various different OEM brake bias figures for the e30 (and a couple of other e models) I arrived upon a Wilwood caliper that gave me what I wanted. Then there was the caliper adapter to work out. I fabbed this in 12mm MDF at first to see if I was ballpark, and then tried making the things with more accuracy. It was sh*t! I decided to buy a 3D printer so that I could proto them. That in itself was a fun exercise as I had to learn how to make the printer behave properly, and then learn how to code the design in OpenSCAD. The adapter was printed, thread tapped, and tested. All good, so I sent the CAD to a machinist to make them in 12mm steel for me.
The eccentrics were a PITA...I should have just left the KMAC eccentric bushes in it! I ended up finding an ARP 14mm 12 point nut for the adjusters and this makes accessing the outermost lock nuts MUCH easier.
The wheels...OMG...I sweated over that. I pretty much resigned to getting custom wheels made, but I was very uncertain on the offsets and sizes. A friend of mine lent me the wheels off his e36; OEM BMW Style 68. The ones he had were 17x7.5" ET41, and 17x8.5" ET25. I fitted the rear onto the car and dropped it down...BAM! They fit SO damned well! With 15mm of spacer in the front, the ET41 wheels also fit up beautifully! If only BMW made these in an ET25 huh...
Days later, while surfing the web for places to buy the Style 68 from, I saw an OEM PN for the 68's that didn't ring true. WTF is that PN? As it turns out, the 68's were also available in an ET25 7.5" which was on the rear of the USA e40 M3! Whoohoo! So I ordered a new set of those from Pelican parts!
The car now runs RS-RR 215 in front, and RS-RR 235 in the rear. The rears must still be scrubbing in because the car is TOTALLY hosing them off when boost comes on.
While I was in the engine bay fitting the e32 MC, I removed the post IC boost pipe and found a 20mm long tear in one of the silicone couplers! Well, I guess that might explain a few things then:
1. Why won't it run more than 18psi?
2. Why are the intake temps so high?
3. Why did the AFR drop to 11:1 past 5000rpm when it had been running a solid 12:1? (hint; a VE drop)
The car is now coming on boost much harder than before, so that rip had a significant effect.
Great to have it back on the road, and it got a 3rd place (in it's class) in the Shannons German Auto Day last weekend.
Oh, and an S55 M3 7sp DCT box has been purchased for it ;-)
DSC01791_2.JPGDSC01800_2.JPGDSC01801.JPG
Last edited by Nutzy; 10-02-2019 at 12:46 AM.
1989 E30 - M50B28 Turbo - ZF 8 Speed
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