E34 M5 Plenum?

**Knight F Mohawk** · 07-04-2013, 07:29 PM

Does anybody have some images of the plenum or a diagram of the DME design?

I have an idea that I would like to try for a nitrous setup, but I need to know how the plenum is designed.

Thanks,

-Will

**Binjammin** · 07-04-2013, 08:29 PM

let me google that for you?

**Knight F Mohawk** · 07-04-2013, 09:44 PM

Originally Posted by Binjammin

let me google that for you?

I did google it, and I didn't quite find what I was looking for.

-Will

**NikosX** · 07-04-2013, 10:06 PM

You're ready to tear that thing down for a rebuild aren't you?

**5mall5nail5** · 07-04-2013, 11:03 PM

Knight what do you want to know? Don't be afraid of nitrous. People think nitrous blows engines up. Stupidity blows engines up. Nitrous makes them faster.

**NikosX** · 07-05-2013, 12:24 AM

Originally Posted by 5mall5nail5

Knight what do you want to know? Don't be afraid of nitrous. People think nitrous blows engines up. Stupidity blows engines up. Nitrous makes them faster.

Stupidity is running nitrous on a 22 year old never opened s38 with high miles without being absolutely sure the motor is solid and the HG has all of its integrity. Nothing against you Will. Just be sure it's all good first.

Thanks for the kick in the nuts Jon. Always appreciated.

**Knight F Mohawk** · 07-05-2013, 01:09 AM

I've sprayed a few vehicles with great results. I'm sure it will happen eventually, but so far I have never killed an engine with nitrous. Getting lazy or greedy is when nitrous usually breaks things. I'm not afraid of nitrous at all. I'm currently discussing an interesting nitrous setup for an S38 that I know for a fact has worked very well on LSx vehicles for awhile. It's not the cheapest route, but it is much more safe and "neat" if nothing else.To address the other question that was asked, I'll rebuild it if I have to. It wouldn't be my first engine build, and I doubt it's my last. If nitrous killed it, I can say that it would be the first engine I ever had to rebuild due to nitrous. It has been well maintained, the compression test looked good, and I'm comfortable starting out with a small shot. You are correct, it is a high miles engine. If it blows, I just get to build a better one

-Will

- - - Updated - - -

Niko, your PM box is full

-Will

**5mall5nail5** · 07-05-2013, 08:00 AM

Originally Posted by NikosX

Stupidity is running nitrous on a 22 year old never opened s38 with high miles without being absolutely sure the motor is solid and the HG has all of its integrity. Nothing against you Will. Just be sure it's all good first.

Thanks for the kick in the nuts Jon. Always appreciated.

Ran 16 psi from a 76mm t4 in a buddies E30 M3 w/ S38 on a 22 year old never opened S38 with high miles and did like 600 rwhp without issue!

Stop being so scared!

**NikosX** · 07-05-2013, 11:35 AM

Originally Posted by 5mall5nail5

Ran 16 psi from a 76mm t4 in a buddies E30 M3 w/ S38 on a 22 year old never opened S38 with high miles and did like 600 rwhp without issue!

Stop being so scared!

I've personally seen 5 blown S38 headgaskets on well cared for cars. Sound like a coincidence?

**richinvan** · 07-05-2013, 12:56 PM

**Binjammin** · 07-05-2013, 02:40 PM

it's not a coincidence that 5 s38 head gaskets have failed, they're old engines and who knows what kind of life all of them lived. at the same time, they are long heads and susceptible to gasket failure and warpage. installing nitrous won't necesarily kill ANY engine if a decent setup is installed. the good old days of "spray and pray" are gone (assuming the proper money is spent) and there should be no fear of nitrous as a power adder.

**Knight F Mohawk** · 07-09-2013, 09:39 PM

Bump for anybody with a good plenum/intake pic

-Will

**93FIM5** · 07-10-2013, 12:37 AM

What type of pic are you looking for I have a spare plenum apart and some CAD let me know.

-Greg

**5mall5nail5** · 07-10-2013, 08:19 AM

Originally Posted by NikosX

I've personally seen 5 blown S38 headgaskets on well cared for cars. Sound like a coincidence?

Welp. That's that.

**Knight F Mohawk** · 07-11-2013, 09:59 PM

Originally Posted by 93FIM5

What type of pic are you looking for I have a spare plenum apart and some CAD let me know.

-Greg

Any images of the inside or design images of the design. Specifically any baffles that may exist and the location of the DME flaps.

-Will

**93FIM5** · 07-15-2013, 03:43 PM

Originally Posted by Knight F Mohawk

Any images of the inside or design images of the design. Specifically any baffles that may exist and the location of the DME flaps.

-Will

Here is a stock photo from the net, funny it shows a groove that would hold a gasket but none of the plenums I've had apart have this or a gasket. So its most likely a pre-production design/part.

Here is my spare plenum apart.

The first pic shows the variable resonance plate and wall. You can also see the effort in the construction BMW put into feed/resonance tube which actually has a velocity stack on the tube ends. Let me know what else you need, like I mentioned I have some CAD files and lots of measurements but they have more to do with the composite plenum I'm building for a few guys.

-Greg

**Knight F Mohawk** · 07-17-2013, 09:32 PM

Many thanks

**93FIM5** · 07-19-2013, 10:09 AM

No problem, let me know if you need help with anything else.

**Layne** · 07-19-2013, 10:17 AM

What's the cannister hanging off the bottom? Just an oil trap?

**93FIM5** · 07-19-2013, 10:22 AM

Originally Posted by Layne

What's the cannister hanging off the bottom? Just an oil trap?

Yea a crank case ventilation setup. A breather hose from the valve cover hooks to it and there is a port in the bottom of the plenum where the air from the airbox passes over it and then a drain at the bottom that hooks to the dipstick.