S52 power potential > S50?

[Kilomph]

It seems like all the S52 OBD-Is are running too rich/lean or have expensive custom tuning though. If I get an aftermarket chip, wouldn't it be tuned for an S50? I know nothing about RRFPR, but i'm guessing that's what I should be reading up on...

I'm thinking with an S50 i'd end up with a properly tuned engine for a lot less cabbage.

[Jason89i]

When you convert a s52 to OBD1 you have all the greatness (almost) of a s50 except you have about 30 more hp at the crank..........my engine of choice would be the s50 though

im curious as to why you would want the s50 over the s52? on the street, the s52 gets better low torque (stroked) but at the track i suppose the s50 seems a little happier above 7k rpm. Stu also forgot to mention that the early s50's have the soft valve retainers.....better replace those or kiss it goodbye. regarding power, my e30s52 (stock cams) will run door to door (40-120) with an identical e30s50 (with tms schrick cam kit.) so, how is the s50 superior to the s52?

cheers, jason

[Stu]

Yea the retainers were problematic for 3.0's up to 10/95. Fortunately it's no issue if the engine is being built anyhow.

Alex's 3.2obd-1 (identicle to mine less crank, piston machining, and software pulled 250whp/228, my 3.0 did 234/213. His car pulls much harder 2000-4000, but when we drag raced them, they were even up to 60ish, then my 3liter would start to slowly pull away in the top of third, steadily to 7200. We swapped passengers for ballast and got the same results.
His 3.2 (though we had identicle head work) peaked and dropped after 6600, my 3.0 peaked at around the same but flatlined to 7200.
His 3.2 had more useable power for driving around town though. Plus, at my local track, there are 3-4 corners where I could use the grunt below 4000.

[1990m3]

what happened to your brother Stu? He's been out of the scene for a while now. I'm sure he still has a car, but he hasn't shown himself on a forum in forever

I have nothing to contribute to this thread except that an s50 swap is minimally more simplistic than an s52 swap. I did an s50, it was pretty much a no brainer swap...

[Stu]

He has been out of it since he sold the M3. He's in NYC doing an internship with a finance firm, should be back here in 2 weeks. He has a 318is that pulls 110 compression on 2 cylinders, and that's fine with him. I'm sure he'll have more very fast cars in a couple years but they're not his focus right now.

[1990m3]

is that his m3 that is now painted yellow with a euro motor in it? It looks like the same front bumper

[Stu]

No, the owner of that car just put the same bumper on it from CDOC. They made a batch of about 25 of them I believe.
Alex's car is about the same as before, but with big swaybars and a couple other things.

[aeryk7]

In my experiences the s50 feels stronger from 5500 to 7200 which i love, i could careless about about the feeling from down low as long as i know i can make up for it up top, especially helpful for track driving. Example of this my S50 car would get to 160mph much faster than my s52 ,it just pulled harder from 120 -160 even with the 3.15 compared to the 3.23 on the s52. I also feel the S50 is more simplistic of course being OBD1 but just the setup in general valve cover/coil setup lots of things had been updated in 96 that just clustered everything. Obd1 cars didnt have traction control ,throttle body obviously different boot also etc etc....all these things can be converted on an s52 but why waste the time and money. As far as the softer retainers i have not had an issue with these yet and have been beating the ever loving sh1t out of s50's for almost 5 years.

[Jason89i]

His 3.2 had more useable power for driving around town though. Plus, at my local track, there are 3-4 corners where I could use the grunt below 4000.

agreed, i have noticed that with the s52 im shifting a lot earlier and using the low grunt rather than running it out past 7k. my old e30m50 would rip 3rd gear through turn 5 all the way to track out at 7200, but the s52 doesnt like much over 6900....now, im shifting even before i enter turn 5 at blackhawk.

cheers, jason

[aeryk7]

In every experience i have had E36 M3 with similar mods *almost* always run door from a second gear roll to the end of 4th ,unless cammed or coverted to obd1; what would be interesting is to swap 3.23 in a obd1 car to see if there is a difference. I found this out only because i have a good amount of street time through a local bmw club against other M's modded etc.

[Jason89i]

In every experience i have had E36 M3 with similar mods *almost* always run door from a second gear roll to the end of 4th ,unless cammed or coverted to obd1; .

well, i assumed we were talking about e30s5x's......s50 obd1 vs. s52 obd1. its not really fair to compare an obd2 s52 to an obd1 s50. similarly prepared cars, the s52 will pull on the s50. cheers, jason

[aeryk7]

Yeah ,thats my bad i guess the thread asked which had more potential and its always gonna be an s52 because the fact you can convert to obd1.

I was just saying without converting an s52 an s50 with similar mods will be right there door to door....i have experienced this with many E36 M cars through my local bmw club

[1990m3]

jason - once I get this crap sorted out I think you and I should do a few pulls on the street. I'm really curious to see how different they are...

[Bennetts22@aol.com]

heres my thought.. I have a S52 amd i love it. The S50's are getting harder to find and most of them have over 100k on them. i bought a 99 m3 with 90k on it for 4000. parted it out and had 1200 in the motor and trans.. My 95 i had with the blower was fast but was a turtle untill 4500 rpms. The 98 m3 i had had alot of bottom end. and not as much up top.. In my thoughts the the s52 with the obd 1 and lightwieght flywheel and such is totaly different then when it was in the e36. You are basically bolting all the s50 stuff on to engine to convert it. In fact i think my s52 revs faster then my s14 and pulls like a bitch over 5 to 7500 rpms.. When i got the swap done i left the 4.10 diff in from the IS. I had to shift like a race kart and the car maxed out at 120 mph.. now i have the m coupe 3.15 and love it. had it going 135 today and it pulled all the way. cant wait till i can make a few pulls with 1990m3 as we have the same mods but a s50 and s52..

cheers

[X2theZ3]

heres my thought.. I have a S52 amd i love it. The S50's are getting harder to find and most of them have over 100k on them. i bought a 99 m3 with 90k on it for 4000. parted it out and had 1200 in the motor and trans.. My 95 i had with the blower was fast but was a turtle untill 4500 rpms. The 98 m3 i had had alot of bottom end. and not as much up top.. In my thoughts the the s52 with the obd 1 and lightwieght flywheel and such is totaly different then when it was in the e36. You are basically bolting all the s50 stuff on to engine to convert it. In fact i think my s52 revs faster then my s14 and pulls like a bitch over 5 to 7500 rpms.. When i got the swap done i left the 4.10 diff in from the IS. I had to shift like a race kart and the car maxed out at 120 mph.. now i have the m coupe 3.15 and love it. had it going 135 today and it pulled all the way. cant wait till i can make a few pulls with 1990m3 as we have the same mods but a s50 and s52..

cheers

Cool,

Let me know how the pulls turn out: i'm very interested in the results.