How far can you take an S38 without pulling the head?

Specific conversations and info for the BMW E28 M5 and M535i.
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Justin in C'ville
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Joined: Feb 12, 2006 12:00 PM

Post by Justin in C'ville »

It looks like my S38 to E12 budget just got a little bigger (If only Al would get back from the desert......) Besides the obvious things, chip (allready got) Exhaust cam gear, 3" straight exhaust.... what else could be done? i'm assuming the head would have to be removed to install hotter cams? I don't know if headers would work because i am dropping this thing into an E12 and they may/may not clear. Can the throttle bodies be upgraded to 3.6 or euro spec? and do i even want to know how much that would cost? Also, does anybody have dyno charts for a modified S38. I have one for my motor that shows 230/225 rwhp/tq.

thanks!
Steve Haygood
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Location: Thomaston Ga
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Post by Steve Haygood »

Head does not need to be removed to replace the cams......nice thing about the M cars ;) Throttle bodies can be rebuilt or replaced, but not cheap( already done on mine when I got it)
Matt
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Location: Fargo

Post by Matt »

I dont think you have to pull the head, because the S38 has a separate "cam box" that rides ontop of the head that the cams sit in. A cam swap might be as simple as pulling the valve cover and a few other exposed things.

One thing you can do is look at the differences between the US and Euro S38s.

- euro had higher comp pistons
- euro had better cams
- euro had equal length headers
- euro had software
- euro had no catalyst

this accounts for the 30hp difference between the S38 USA and S38 Euro. The biggest difference would be the comp ratio, which obviously you cant get.

Many people say a 272/264 cam setup (272 from schrick, 264 from S38B36 (e34 m5)) is a fantastic street setup for the S38. That and a nice set of headers plus conforti software will be about all you'll get out of it without real work. The exhaust cam gear is probably also helpful.
Justin in C'ville
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Joined: Feb 12, 2006 12:00 PM

Post by Justin in C'ville »

[QUOTE="Steve Haygood"]Head does not need to be removed to replace the cams......nice thing about the M cars ;) Throttle bodies can be rebuilt or replaced, but not cheap( already done on mine when I got it)[/QUOTE]

you wouldn't happen to have a source for these cams would you steve??

I found some of the same info by searching the M5 board at roadfly. so i guess i'll have to be satisfied with a meager 270hp or so. good thing i've got the E28 :).
Cacatfish
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Joined: Feb 12, 2006 12:00 PM

Post by Cacatfish »

I think the 272 Schrick cams are readily available for the S38, but the 264 I believe to be very hard to come by as most all of them have the larger base circle for the M88 head and will not fit the S38.

You can still run 272 on both sides or even 282 intake and 272 exhaust. Jon Kofod ran this combo on his race car and made 247whp with straight exhaust. Definitely get a set of Euro headers while you are at it. I have heard from a few sources that the MAF kit is worth abot 15hp and possibly more on a heavily modded motor. The best dyno I have seen was with MAF, stock cams, JC chip and maybe Euro headers. I think that was 252whp or so (maybe it did have cams, dont recall).

Of course, this stuff gets expensive real quick and if you already have 230whp (very strong for a chipped S38) then Im not sure if you want to drop another $3k-$4k for just another 20whp. I guess it is addictive though and it sure does sound fun!
Matt
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Joined: Feb 12, 2006 12:00 PM
Location: Fargo

Post by Matt »

Negative.

The 264 is stock for the S35B36 (E34 M5).

The usa motor is 248 248 i think, while the B36 motor iirc has a 264 in it somewhere. There's an S38 yahoo list that talks about this all the time, you might try asking there.
Cacatfish
Posts: 106
Joined: Feb 12, 2006 12:00 PM

Post by Cacatfish »

Oh yeah that's right! I totally forgot about the E34 M5 cams. I think they are 264 both sides and interchange with the S38B35 cams.
Another note, the throttles are the same size for Euro and US car, though I dont know about the E34 ones.
Duke
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Location: Ormond Beach, FL

Post by Duke »

Don't forget about a stand alone MODERN ECU such as the Electromotive TEC3 system. Guaranteed to squeeze more HP out of any engine.
Steve Haygood
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Location: Thomaston Ga
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Post by Steve Haygood »

yes I do have an e34 M5 cam available that I wouldn't mind selling
fastpat
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Location: Travelers Rest, South Carolina

Post by fastpat »

[QUOTE="Steve Haygood"]yes I do have an e34 M5 cam available that I wouldn't mind selling[/QUOTE]

I was talking with Devinder Grewal about this swap, he said that the euro e28 cams have a different base circle or something like that. He'd like to know that the late M5 cams fit his US-spec engine.
Guest

Post by Guest »

Justin,

If you want cams look for a set of used cams from an E34M5. These are 264 degree cams as others have mentioned and have the correct base circle for use in the S38 version of the ///M engine. For throttle bodies you would need to go to the ones from the same, but you should also procure the plenum, control box for the resonance flap and the wiring harness for the same. The pdf file at the link goes into the technical details of the intake system and also has enough info to allow one to retrofit the system.

http://www.bmw-m.net/techdata/m5engine.htm

HTH

Rich
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