m30b35 performance

[mewherman]

So I have a deal pending on an E12 parts car which will substantially help my project parts issues. So in the mean time I've put the car back together and been driving it and working on the mechanical issues and fixing all the issues with the poorly done previous work.

So I've cleaned up a lot of the bad wiring, and I've installed an o2 sensor and bung because it didn't have one at all. I've also set up the engine light to illuminate the "reactor service" lamp on the dash information center for the original engine. I also installed a new fan clutch and blade because both parts were somehow missing.

I noted this in my other thread but I was hoping for more input but the car is a total slug, It feels torquey and all on the grid roads but once you're trying to beat on it it's pretty disappointing. My issue is that I have no idea what the performance should be in an e12 with this 3.5 engine. But I would imagine that since it's apparently more powerful than the 2.8 engine then it should at least be faster than a stock 528i but it is in fact slower than a stock 528i. Best 0-60 time we got out of it was 12 seconds which is slow as fuck and I didn't get it much over 100mph. The specs on the m535i which admittedly did have about 10 more hp than this car were something like 7 seconds to 60 and a top end in the 140s. That would be blistering in comparison.

The car doesn't throw any trouble codes and seems to run fine, under part throttle acceleration it does sort of feel like it's got a slight hesitation a bit of an undulation in the power delivery. One thing I did try was cleaning the fuel injectors with one of those OTC tools you hook up in place of the fuel system and run the car on injector cleaner, this made no difference.

Here are some ideas I have as to why it's so slow.

Restrictive exhaust: the person who put the engine in has welded the double downpipes into the stock single exhaust essentially reducing it by 50%.

Hot air intake: the original intake is missing and there is a crappy cone filter directly above the exhaust manifolds.

Larger than stock wheels and tires: The original turbines are missing and the car wears some 15 inch style 5s which are probably off the e34 the engine is from this has caused a 10kmh/hr speedo error.

Rear axel ratio: This started life as a sierrabeige 528i so perhaps the rear end on this car has highway gears in it, not sure how to check the rear axel ratio to be honest, it's not an LSD I can tell you that!

Or perhaps it is a combination of all these things.

[Theotherotter]

My E12 has a B35 with a chip and MAF conversion, dead stock for an '89 (California legal) and it's not fast by modern standards, where plug-in cute-utes have 300hp and sub-six-second 0-60 times, but it certainly isn't slow and has torque for days. It'll pull cleanly from 30mph in 5th. I don't have any reference in other E12/E28 drivetrains, though. Mine is the only one I've driven. Feels like it could be a seven-second car if you beat on it.

Keep in mind that magazine 0-60 times require beating on the car.

The diff housing should have a pair of numbers cast or painted (I don't remember which) on the outside - I think it's on the right side. Divide the larger by the smaller and you have the ratio.

[mewherman]

My E12 has a B35 with a chip and MAF conversion, dead stock for an '89 (California legal) and it's not fast by modern standards, where plug-in cute-utes have 300hp and sub-six-second 0-60 times, but it certainly isn't slow and has torque for days. It'll pull cleanly from 30mph in 5th. I don't have any reference in other E12/E28 drivetrains, though. Mine is the only one I've driven. Feels like it could be a seven-second car if you beat on it.

Keep in mind that magazine 0-60 times require beating on the car.

The diff housing should have a pair of numbers cast or painted (I don't remember which) on the outside - I think it's on the right side. Divide the larger by the smaller and you have the ratio.

This car feels slow, there is no way it's going to go faster than 10 seconds to 60, and it is never getting to 125mph, which is something it would have been able to do with the stock engine.

It doesn't feel like 200hp it feels like 140hp or something. We have an old v6 Malibu at work as a courtesy car and the Malibu would blow the doors off this thing in the 1/4

[Theotherotter]

Have you checked the basic things like ignition timing? What do the plugs look like?

[mewherman]

Have you checked the basic things like ignition timing? What do the plugs look like?

This is on Motronic I.3, so the ignition timing isn't adjustable. It has all new plugs since 1000km ago along with a cap and rotor. I also checked the valve clearances at that time, which were in spec. I didn't do the wires, but it doesn't miss or anything, it's just down on power.

The car has all kinds of vacuum lines missing, and I have gone around plugging the ports off, I assume this was for some EVAP stuff but the person who did the swap didn't include these items and had done quite the hack job of "deleting" them.

[Chimi-Changa]

If you jack up the rear in neutral, and pull rear cover off you can count how many revolutions needed for one whole turn of the big rear gear. If it has a 2.93- it will take that many turns of the drive wheel to turn the gear one full spin. Marking the tire with something like a grease pencil makes it easier.

[Theotherotter]

Have you checked the basic things like ignition timing? What do the plugs look like?

This is on Motronic I.3, so the ignition timing isn't adjustable. It has all new plugs since 1000km ago along with a cap and rotor. I also checked the valve clearances at that time, which were in spec. I didn't do the wires, but it doesn't miss or anything, it's just down on power.

The car has all kinds of vacuum lines missing, and I have gone around plugging the ports off, I assume this was for some EVAP stuff but the person who did the swap didn't include these items and had done quite the hack job of "deleting" them.

Even the base timing isn’t adjustable? That doesn’t sound right. Mine is also Motronic 1.3 and I havent had to touch a thing on it. My only real point of reference is the stock system on my Sentra SE-R, which is of similar vintage.

Hav you done compression and leak-down tests?

[mewherman]

This is on Motronic I.3, so the ignition timing isn't adjustable. It has all new plugs since 1000km ago along with a cap and rotor. I also checked the valve clearances at that time, which were in spec. I didn't do the wires, but it doesn't miss or anything, it's just down on power.

The car has all kinds of vacuum lines missing, and I have gone around plugging the ports off, I assume this was for some EVAP stuff but the person who did the swap didn't include these items and had done quite the hack job of "deleting" them.

Even the base timing isn’t adjustable? That doesn’t sound right. Mine is also Motronic 1.3 and I havent had to touch a thing on it. My only real point of reference is the stock system on my Sentra SE-R, which is of similar vintage.

Hav you done compression and leak-down tests?

No I don't think so, it doesn't have any mechanical means of advancing or retarding the timing, the rotor is bolted to the end of the camshaft. From what I've read, it's all a function of the ECU. I haven't done a compression test, I will if it comes down to it, but the engine runs fine with no smoke or blowby and doesn't sound unhealthy, so it would have to be low on compression across all six.

If I have time today I'm going to check for intake vacuum leaks, I think that could be an issue based on its behaviour.

[Mike W.]

No I don't think so, it doesn't have any mechanical means of advancing or retarding the timing, the rotor is bolted to the end of the camshaft. From what I've read, it's all a function of the ECU.

Correct, timing on Motronic cars is not adjustable, except by a different chip in the ECU. The only sort of exception to that is some, but I think only 1.0, not 1.1 or 1.3, there is a switch inside the ECU that can change fuel trim a little bit and retard the ignition slightly. It's called a fuel quality switch to allow operation on really crappy low octane gas, not to adjust or enhance performance.

But stock, 2.8, E12s are quick. Not 300 HP quick, but around 8 seconds 0-60 and low 16's in the quarter mile. Top speed was around 120.

My last E12 was a dog, even with a fresh euro 3.5 engine. I estimated around 140HP. Tried a different exhaust/cat and exact same. Until finally I put a third cat on and holy shit! Wow, it was a muscle car. With absolutely ancient tires on it, I could floor it at any speed in first gear and spin the tires. Not drop the clutch, just push down. Two semi plugged cats with essentially identical performance. What are the odds.

Back to yours, it should be plenty quick. Different diff ratios were available for E12 sideloader diffs, but very few other than 3.45 and 3.64. Do a compression check, but I can't imagine it would even start if it was so low that a B35 was down on power as far as you are experiencing. Run yes, but not start off the starter. Drop the exhaust at some point, I don't recall if it has a cat or not, but just for testing to make sure somethings not plugged. Unless it's got a dead cylinder or two or crossed spark plug cables, but I suspect idle would be pretty crappy if that was the case.

[mewherman]

No I don't think so, it doesn't have any mechanical means of advancing or retarding the timing, the rotor is bolted to the end of the camshaft. From what I've read, it's all a function of the ECU.

Correct, timing on Motronic cars is not adjustable, except by a different chip in the ECU. The only sort of exception to that is some, but I think only 1.0, not 1.1 or 1.3, there is a switch inside the ECU that can change fuel trim a little bit and retard the ignition slightly. It's called a fuel quality switch to allow operation on really crappy low octane gas, not to adjust or enhance performance.

But stock, 2.8, E12s are quick. Not 300 HP quick, but around 8 seconds 0-60 and low 16's in the quarter mile. Top speed was around 120.

My last E12 was a dog, even with a fresh euro 3.5 engine. I estimated around 140HP. Tried a different exhaust/cat and exact same. Until finally I put a third cat on and holy shit! Wow, it was a muscle car. With absolutely ancient tires on it, I could floor it at any speed in first gear and spin the tires. Not drop the clutch, just push down. Two semi plugged cats with essentially identical performance. What are the odds.

Back to yours, it should be plenty quick. Different diff ratios were available for E12 sideloader diffs, but very few other than 3.45 and 3.64. Do a compression check, but I can't imagine it would even start if it was so low that a B35 was down on power as far as you are experiencing. Run yes, but not start off the starter. Drop the exhaust at some point, I don't recall if it has a cat or not, but just for testing to make sure something's not plugged. Unless it's got a dead cylinder or two or crossed spark plug cables, but I suspect idle would be pretty crappy if that was the case.

I've been suspecting an exhaust issue because the previous owner has as I say taken the two downpipes off the split manifolds and spliced them into a single exhaust system with a basic muffler at the back, no cats or anything are on the car at all. I've been temped to cut the exhaust off at the downpipes just to see if it makes any difference, but then I'm stuck with a car with a hacked off exhaust.

Yes, the engine idles and starts up totally fine and accelerates smoothly with no vibration or smoke or anything, it's just slow as dog shit.

[mewherman]

No I don't think so, it doesn't have any mechanical means of advancing or retarding the timing, the rotor is bolted to the end of the camshaft. From what I've read, it's all a function of the ECU.

Correct, timing on Motronic cars is not adjustable, except by a different chip in the ECU. The only sort of exception to that is some, but I think only 1.0, not 1.1 or 1.3, there is a switch inside the ECU that can change fuel trim a little bit and retard the ignition slightly. It's called a fuel quality switch to allow operation on really crappy low octane gas, not to adjust or enhance performance.

But stock, 2.8, E12s are quick. Not 300 HP quick, but around 8 seconds 0-60 and low 16's in the quarter mile. Top speed was around 120.

My last E12 was a dog, even with a fresh euro 3.5 engine. I estimated around 140HP. Tried a different exhaust/cat and exact same. Until finally I put a third cat on and holy shit! Wow, it was a muscle car. With absolutely ancient tires on it, I could floor it at any speed in first gear and spin the tires. Not drop the clutch, just push down. Two semi plugged cats with essentially identical performance. What are the odds.

Back to yours, it should be plenty quick. Different diff ratios were available for E12 sideloader diffs, but very few other than 3.45 and 3.64. Do a compression check, but I can't imagine it would even start if it was so low that a B35 was down on power as far as you are experiencing. Run yes, but not start off the starter. Drop the exhaust at some point, I don't recall if it has a cat or not, but just for testing to make sure somethings not plugged. Unless it's got a dead cylinder or two or crossed spark plug cables, but I suspect idle would be pretty crappy if that was the case.

Alright, so I unbolted the exhaust from the manifold and drove it around, It was a little bit better maybe? But mostly it was just noisy, and I was worried it would catch fire. I wouldn't say that the exhaust is the issue. It didn't make a very significant difference.

[mewherman]

Is it possible the timing chain is stretched? Or it's been assembled one tooth out? Or would it not run at all in that situation?

[Mike W.]

Alright, so I unbolted the exhaust from the manifold and drove it around, It was a little bit better maybe? But mostly it was just noisy, and I was worried it would catch fire. I wouldn't say that the exhaust is the issue. It didn't make a very significant difference.

OK, from your description of things, it's not the problem. Maybe not 300HP fast, but it should feel quick, put you back in the seat quick.

Is it possible the timing chain is stretched? Or it's been assembled one tooth out? Or would it not run at all in that situation?

Stretched, no. But out of time... who knows? You'll probably have to pull the upper timing cover to really check, and it's kind of odd the way it's set up, but it is, but certainly at this point it's worth a shot. If you don't have a manual on how to time it PM me with an email and I can send you the pages from the manual in pdf.

[mewherman]

Alright, so I unbolted the exhaust from the manifold and drove it around, It was a little bit better maybe? But mostly it was just noisy, and I was worried it would catch fire. I wouldn't say that the exhaust is the issue. It didn't make a very significant difference.

OK, from your description of things, it's not the problem. Maybe not 300HP fast, but it should feel quick, put you back in the seat quick.

Is it possible the timing chain is stretched? Or it's been assembled one tooth out? Or would it not run at all in that situation?

Stretched, no. But out of time... who knows? You'll probably have to pull the upper timing cover to really check, and it's kind of odd the way it's set up, but it is, but certainly at this point it's worth a shot. If you don't have a manual on how to time it PM me with an email and I can send you the pages from the manual in pdf.

I might go to the u pull it and try to find one of these engines and steal the AFM and TPS and sand ECU everything out of it and try swapping stuff around. Thing is, I know nothing about this engine's history or what car it came out of or how many miles are on it. It may well be that there is some sensor or something missing that I don't even know about, there are certainly a plethora of connectors not hooked up to anything. But I would have thought that the engine light would be on if there were anything important disconnected.

[mewherman]

Well, I took the timing cover off this afternoon, and it appears to be in time based on what I've read about this engine, seems very straight forward as far as these things go. The engine is very clean inside, as I previously noted when I checked the valve clearances. The chain wasn't loose or anything. Doesn't hurt my feelings to take this apart, as the cover was leaking oil everywhere and needed to be resealed anyway. I'll replace all the gaskets.

One thing I did find was that the intake boot between the AFM and the throttle body, the clamp for this was completely loose at the throttle body, I had sprayed for vacuum leaks with brake clean yesterday with no results but maybe this is an issue at higher loads. I'm going to replace every vacuum hose anyway. I also found out the thermostat is broken on one side so that will be replaced as well.