I Have a Problem
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Long time no update
This thing has been a struggle.Things that were happening; engine was stumbling around 3200-3500rpm and sometimes wouldn't push past it, light throttle would allow those revs. Would hit some form of limiter far before what the hard limit is set to.
I thought it may be due to 92 octane (10% ethanol) vs the tune being for 91 no ethanol. I tracked down some 92 no ethanol (technically not legal in WA) and tried that. No dice
Hooked up a wideband to see what it was doing in that range and noticed that it would lean out on light accel and was running right on the edge of what seems comfortable for being too lean.Took the fuel pump out while I was trying to further investigate my lack of fuel gauge and was reminded of the time when the pump in this car was being changed and I noted you couldn't dangle a fuel pump with a piece of wire cable tied to the fuel pump bracket. I dropped the pump back down and verified the pickup of the pump was sitting on the bottom of the fuel tank.
Drove again and the AFR's came back nicely, but still struggling a bit in that 3k and rev limit range, though I noted a strong increase in midrange torque.I had been monitoring spark plugs and cylinder tops and had noted that each time cylinder 6 was wet on top, and so was the half of cyl 5 that is near 6. Tried blowing them off to see if it was fuel from a leaky injector or something of the like and nothing happened. Cylinder 5 and 6 were the lowest in a compression test, so the head came off assuming the HG didn't manage to hold through the lean abuse.
Off came the head, the old gasket did have faint notes of failure.
I decided to go with another MLS as my last cut ring experience was not good, and I was unsure if the stock HG would allow for the 87mm bore pistons. When removing the old gasket it seemed thicker than it should be (.08" was the previous order) and I verified that this engine has been using a .100" thick gasket this whole time. A rough ratio shows that it brought the compression back to just about stock.
I ordered stock thickness so we will see a hair above 11.5:1 compression now.Started reassembling the engine and got everything timed up and assembled, went to install the primary chain tensioner and it never got tight. Surprise no more threads in the tensioner hole.
Called around to see who had an M26 helicoil with no success. Tried a local E36 shop who said on the phone they had them and could fix it, drove an hour there to drop it off, waited for 2.5 hours, then got a call saying they couldn't fix it and they didn't think they even made helicoils that big. That was a colossal waste of time and made me super happy.
i ended up ordering a kit to helicoil it as I'm not super keen on welding in that hole and would still need to pay someone to bore it back out and tap it again.In good news I finally took it from the original (adorable) early 318i front brakes to the late model brakes with all new parts.
Hoping to have the head back on by Saturday before I leave for another month work trip......This was supposed to be fun to drive and just small projects
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Got the engine back together and was still getting breakup issues around the 3500rpm mark, but wouldn't stumble if I was spinning tire at that point, and got worse as the engine warmed up. Being unsure of the quality of the chip tune, and long time desire to see this dyno tuned, it was finally time to take it in and see if the tune was to blame.
After some wood and time to get it up the dyno ramps (it's not high off the ground...) it was nestled in and the tuning commenced. Yes the door was open for tuning.
The first pull on the chip tune yielded a very lackluster 236hp and 231lbft of torque, and the breakup around 3500rpm really reared its head.
I would be lying if I told you that I was happy with that amount of power, but rolled into it knowing that may happen.
The tuner then took the existing tune out and tossed on one that he had from a roughly similar motor to see how it liked that. The pull was smooth and didn't break up with the new tune, and it sounded much better. I glanced at the screen and saw 296hp flash across it, and I looked at the tuner to verify what I had just seen. He hadn't looked at the number yet, so we went over and looked. Sure shit, first pull with a different tune and we gained 60hp. We were all quite impressed, as that was nearing the highest HP S5x they have ever seen NA, and its a specific E36 shop that builds many a motor.
More tuning commenced and the motor responded really well to any changes and kept improving in powerband and peak numbers, though as the engine would heat-soak the breakup around 3500rpm would return no matter how much fuel or timing was added/removed. That one boils down to a hardware issue somewhere that I am working on tracking down.
After a few hours of playing he finally determined that it was doing the best it could, and put down some serious numbers that everyone was happy with.
We managed to pick up 75hp and 45ftlbs more torque on an NA engine which is simply astounding. The car is now making more TQ across the entire range than it made in horsepower on the chip tune. The rev limit is at 6600rpm right now and once I find that breakup issue when warm (affects rev limit also) I will be going back and having the limit moved up a fair bit as peak horsepower is at redline right now so I will likely continue to make more power.
The car is an absolute machine now, it pulls hard and smooth throughout the whole range and I keep hitting rev limiter because at no point does it feel like I need to shift.
Absolutely stoked with the whole tune, and the guys at the shop were great to work with.
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Great results.
i know you’re OBD1, but was he able to log any IATs or anything during the runs? Heat soak that quickly sounds not fun
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Great results.
i know you’re OBD1, but was he able to log any IATs or anything during the runs? Heat soak that quickly sounds not fun
It's not an intake thing ( I don't think at this point) as the intake tube was cool the whole time. I'm thinking there is a sensor on the fritz or something like that and is affected by temperature. It didn't have the breakup issue in WI but started happening shortly after bringing it out here.
I tried (5) different coils today and that didn't change anything, so will shuffle them around and try again. I had tried a new crank sensor but the new one was DOA. Not entirely sure what else to start chasing down.There's just something about an early model with euro bumpers, it looks so good. Amazing numbers! I bet it's an absolute riot to drive.
It's a classy look for sure, but doesn't sound or drive classy!
Drove it around a bit today, and realized how much I hate the clutch. It was put in when he thought he was going to do boost, so its a stage 39485958 6 puck unsprung on a single mass flywheel. It blows, that's pretty high on the list of things to replace because it simply isn't enjoyable.
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Update time!
I was driving the car around for a day or two after tuning, tearing up the streets and such. Went to a guys house who does E36 racecars and was working on s54 itb adapters for m5x/s5x engines which I wanted to pick his brain about for reasons. Right before I got to his house the temp gauge started climbing above half, figured it was just air so wasn't worried. Before I left his house I opened the expansion tank and worked the hoses a bit. Started my 30 min drive home and made it about 10 before it started overheating. I parked in a gas station and tried for 40 or so minutes to burp the cooling system and add coolant but it was no success. Luckily I was about 5 miles from a friends house who just so happened to not be working that night. I started driving to his place and as I got off the highway I nearly stalled it changing gears as the clutch engagement point was suddenly on the floor... I pumped the pedal once or twice to find out something in the clutch blew out and I could barely get anything.
I continued driving my overheating e30 without using the clutch and trying to time traffic lights correctly. I made it into his apartment complex and parked it, got a ride home, and rented a uhaul trailer (again) to pick the car up.Slave cylinder hydraulic seal blew out, so brake fluid was dumping out of the bellhousing. I bought a new master and slave cyl to accompany the new clutch and not have to worry about it for many years again.
I dropped the trans with the engine in the car which I haven't done before. Not as bad as everyone says it is!
I swapped to a E36 flywheel with 240mm clutch vs the E30 flywheel that was in it at 228mm. The old six puck clutch was indeed required to hold the NA power that this engine is producing which is amusing, but sucks to drive. Swapped to a full face organic disk.
Old clutch/PP/Flywheel weight: 31.4 Lbs.
New clutch/PP/Flywheel weight: 28.4 Lbs.
Three pounds lighter for a better clutch? I'm game! Photo of old clutch so I can remember the abuse it caused.
After using the wrong throw-out bearing the first time which required me to take the trans back out, I was finally at the point where everything was back together and ready for coolant. I poured coolant in and started hearing a trickle, and found a pinhole in my radiator that had 3 hours or so of runtime on it. I must've caught it on something while taking it out. My attempt to solder it was unsuccessful so I ordered another one, thankfully the CSF OE replacement is cheap!
So everything is back together now, and RockAuto sent me the correct crank sensor after they sent me the wrong one (the must've had a mislabeled box or something odd) and it seems the crank sensor was the cause of my breakup and stumbling issues, as the car now pulls smoothly to 7?00 RPM. I would like to get back on the dyno to make sure that top rev range is tuned and to see where the power starts to taper.
The new clutch is so damn nice to drive with, frankly it should've been the first thing I did to the car when I got it. The ability to slip the clutch and not have the car lurching is lovely, and as resulted in me driving this thing a lot more than it ever has been since I've known it.It does still have the issue of losing traction in 3rd gear on moist pavement at 65mph though. I need to work on that one yet!
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It does still have the issue of losing traction in 3rd gear on moist pavement at 65mph though. I need to work on that one yet!
I think you should post a video of this. You know, for scientific purposes.
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I think you should post a video of this. You know, for scientific purposes.
Ahhh man an excuse to go beat on the car... I hate those!
Note my overzealous let-off that had me pointing toward another car in oncoming traffic, and the other side being a ditch lol
I hope @B C appreciates the audio, the timing was unintentional.The highway was actually dry enough to let 3rd gear stretch its legs, I always debate going back to a 3.73 in this car, but the 3.25 feels like it takes great advantage of the torque on hand.
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S52 to the moon.
Where it should be 🤩
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Started making an airbox, ended up going down a rabbit hole, will update more later once parts arrive.
I believe I'm going for the highest power NA S52 -
Started making an airbox, ended up going down a rabbit hole, will update more later once parts arrive.
I believe I'm going for the highest power NA S52I like this, interested to see!
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Alright I'm going to start thinking out loud here.
So what I was looking at while working on an airbox is the tight radius elbow that leads into the throttle body on my car. The bimmerworld elbow is used to adapt to the 3.5" MAF but seems to have a tighter radius than stock.
Bends are bad for airflow, and I currently have a tight radius 90 before the throttle body, then a 90 after the filter. Total of 180° of bends.
The E36 chassis needs this bend due to the strut tower location and them being close together, but the strut towers are further back and apart in an E30, and the throttle body is almost entirely forward of it. Random google pic instead of going to my car.
Step 1: New throttle body. I recently stumbled upon someone who put an M60 throttle body (80mm) on an S52. Turns out many years ago Treehouse racing actually made a kit to do this, but I have never seen this or heard about it, and it looks like not many were ever made. The throttle body uses the same TPS, but everything else is different. I picked up one on ebay for $60 shipped. This is the same engine that my MAF is from.
I will be making an adapter that will allow me to bolt this up to my engine, and I will be opening up the hole in the manifold to capitalize on the swap. I will need to make a bracket for the throttle cable as well.
Step 2: Remove 90° bend at throttle body. If I move my coolant expansion tank to the passenger side of the car (plenty of space) I can get away with running (1) 45° elbow at the throttle body, and keep the rest straight with maybe a small bend to accommodate the filter. Taking 135° of bends out of my intake tubing should help, especially with eliminating the tight radius bend before the throttle body.
What I'd like to do is swap this stuff while it's on the dyno and see actual results.
The biggest downside is going to be drivability; currently I barely have to breathe on the throttle pedal to cruise, and this swap will amplify that issue. I will make a different throttle arm if I have enough pedal travel to do so.I don't think this swap ever caught on because it is likely very pointless on a relatively stock engine, but we're far from that in this thread!
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