bmw m90 questions

bavarian

bavarian

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wondering a couple things about the m90

according to previous threads regarding pre 82 m30 heads have a higher chance of cracking due, does this include the pre 82 m90 heads or were they fixed ?
,head gasket part number in the usa? will a s38b35 head gasket work ?
can motronic 1.3 out of a b35 run an m90 even though compression is a bit higher? i do know about the hardware involved in converting just wondering if that stock tube would work well with the higher comp

what wheel horsepower numbers could one expect from a m90 port matched with short tube ie headers, lightweight flywheel, and mega squirt using a csi intake is 210whp doable
 
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Bert Poliakoff

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M90 was rated at 210HP. I modified my M90 and as soon as it is reasonably broken in I will get a dyno pull on it Modified with a little over 10:1 closer to 10.5 pistons, head is ported and port matched( original head, and a 284 cam. I am running Motronic basic and if that ends up not doing it I will go to Motonic 1.3 and use a D'Silva chip When figuring the modifications I was shooting for at least 250hp
 
HB Chris

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Bert Poliakoff said:
M90 was rated at 210HP. I modified my M90 and as soon as it is reasonably broken in I will get a dyno pull on it Modified with a little over 10:1 closer to 10.5 pistons, head is ported and port matched( original head, and a 284 cam. I am running Motronic basic and if that ends up not doing it I will go to Motonic 1.3 and use a D'Silva chip When figuring the modifications I was shooting for at least 250hp
Click to expand...
That’s at the crank, what will be the result at the rear wheels, around 180? I really don’t know, asking for a friend.
 
bavarian

bavarian

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Bert Poliakoff said:
I plan to go on the dyno next month and will post the results
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Bert Poliakoff said:
M90 was rated at 210HP. I modified my M90 and as soon as it is reasonably broken in I will get a dyno pull on it Modified with a little over 10:1 closer to 10.5 pistons, head is ported and port matched( original head, and a 284 cam. I am running Motronic basic and if that ends up not doing it I will go to Motonic 1.3 and use a D'Silva chip When figuring the modifications I was shooting for at least 250hp
Click to expand...
nice sounds like a sweet set up and id really consider the 1.3 if you can find a e34 or e32 at a nearby junkyard, the advantages of the 1.3 is that you can get megasquirt plug and play which is as tunable as it gets , i was wondering do you know which head gasket your using ? if you do have true 250hp at the crank you should see between 205whp- 220whp depending on the rear end and if your transmission is manual, good luck at the dyno
 
lip277

lip277

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I have an M90 set up in progress via SFDon here... I drove the car a few weeks back (for the first time in over 4 years - Wo Hoo!!!) and it was very spunky... VERY much so.
Don can correct me - but I have the stock 9.3:1 comp ratio with a Shrick cam (of moderate sportiness) running off Megasquirt EFI. The ECU program is a 'safe' one till he can get the car to the dyno where it will be tuned to take full advantage of all the power that this set up has availble. Right now, it is limited in revs and power and all (4000 rpm limit? something like that) - pretty tame in general.
Still - even with one hand tied behind its back - That thing was QUICK. Super snappy throttle response. Driving it around Don's shop and out to an open area where I could let is loose (a bit) was just awesome.

I can't wait till that motor has its full potential available.
 
bavarian

bavarian

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lip277 said:
I have an M90 set up in progress via SFDon here... I drove the car a few weeks back (for the first time in over 4 years - Wo Hoo!!!) and it was very spunky... VERY much so.
Don can correct me - but I have the stock 9.3:1 comp ratio with a Shrick cam (of moderate sportiness) running off Megasquirt EFI. The ECU program is a 'safe' one till he can get the car to the dyno where it will be tuned to take full advantage of all the power that this set up has availble. Right now, it is limited in revs and power and all (4000 rpm limit? something like that) - pretty tame in general.
Still - even with one hand tied behind its back - That thing was QUICK. Super snappy throttle response. Driving it around Don's shop and out to an open area where I could let is loose (a bit) was just awesome.

I can't wait till that motor has its full potential available.
Click to expand...
Sounds very nice exactly what I want a mild streetable m90, wonder what intake manifold your running ? M90 is a horsepower m30, the shorter stroke and higher compression allows it to be more of a top end excited engine while keeping its torque !! Your gonna love the extra 2000+ Rpm’s when it’s tuned bc that where the m90 really shineS
 
lip277

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I have a 'period' CSi look to my motor. See pic. The intake runners are from an E21 (a bit longer to give some extra torque).
From there - Don can chime in on what I have and what he expects to get out of it once it gets to the dyno....
 

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sfdon

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We tune for drivability. You push the pedal and instant response.
Instant nice big smooth response. A well tuned M90 with a moderate street cam feels like a turbo engine- give it a little gas and it responds. Give it a lot of gas and it really takes off. We aim for max torque at minimum rpm.
Torque is king for us.
 
bavarian

bavarian

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nice looks like a very clean build very curious on one thing , I've seen you kept the rod driven throttle body in there ... what throttle position sensor did you go with is it out of an m50 and does it bolt in? this would be a big help
 
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