Carbed M30B35 + new exhaust = :)

sreams

sreams

Well-Known Member
Messages
402
Reaction score
27
Location
Sacramento, CA
So... a while back I installed a low-mileage M30B35 into the 3.0cs. I removed the fuel injection system and kept my downdraft Webers and old distributor. In order to keep things simple and inexpensive initially, I kept my old exhaust manifolds in order to mate directly to my existing downpipes.

The old M30 manifolds have (about) 1.5" ID outlets. From there, my exhaust system went from dual 1.5" pipes to a single 1.875" pipe. After that there was a long, thin muffler, more 1.875" pipe, a resonator, and finally 2.125" pipe.

Here's the old system out of the car:

http://www.roadrec.com/oldexhaust.jpg


I pulled the whole system out a few days ago, and installed the stock M30B35 manifolds and downpipes. The manifold outlets and pipes are about 1.875" ID, which means a whole lot more volume than the old 1.5" system. I then went to the local Marco Muffler and went over what I wanted in detail with the guy there. They installed a 2.5" system with three Magna Flow cylindrical mufflers and did an -amazing- job.

Here are pictures, from front to back:

http://www.roadrec.com/e9exhaust1.jpg

http://www.roadrec.com/e9exhaust2.jpg

http://www.roadrec.com/e9exhaust3.jpg

http://www.roadrec.com/e9exhaust4.jpg

The car sounds great... but more importantly, I honestly feel like I've got 40 more hp. It is a night and day difference in power delivery, especially above 3k rpm.

I had read here and elsewhere that M30 engines really like to breathe on the exhaust side, and my experience supports that.

Here's the system in action:

http://youtu.be/VgX6Lc2CmdE

For those who may have followed my previous threads about Weber DGV jetting, here's the current setup with the new exhaust. I'm using a wideband O2 sensor and gauge to assist in getting it really right:

Primary
60 idle
140 main
160 air

Secondary
55 idle
110 main
160 air

This gives me a solid 12-13:1 at WOT throughout the rpm range. I'm surprised that others on this forum are using much larger secondary main jets than I am. I wonder what is different about my setup, if anything.

-Scott
 
Last edited:
Nice!

I built a similar system some years ago. I used an ANSA front resonator with 2x1.75 tubes and a single 2.5" tube with a free flowing muffler after that - sounds great! :-)
 
Last edited:
Looks nice Scott. I am not surprised that you gained some power. The old system from the end of the downpipes back doesn't appear to be stock for the 3.0. In fact, it is smaller than stock. Normally the 1-5/8" (1-1/2" ID) downpipes would both run into the center resonator and then from there it would have gone up in size to a single 2-3/8" (2-1/4 ID) pipe the rest of the way.

A video clip of the new sound?
 
Nice work Scott, cost?

It's nice that you were able to get a workable solution from a commodity supplier. And, I'm hoping it was more cost effective than a system from an E9 specialist. I may end up going down the M30B35 + carbs route myself and information about your successes is very helpful.

John
 
As for cost...

They were very nice guys and seemed genuinely excited to work on the car. They charged for 2 hours of labor ($170). The rest was parts. The mufflers were $80-$90 each. Then there was the pipe, the Y-pipe, the hangars, the chrome tip, and an O2 sensor bung. The total was $600-something.

-Scott
 
Sven said:
Looks nice Scott. I am not surprised that you gained some power. The old system from the end of the downpipes back doesn't appear to be stock for the 3.0. In fact, it is smaller than stock. Normally the 1-5/8" (1-1/2" ID) downpipes would both run into the center resonator and then from there it would have gone up in size to a single 2-3/8" (2-1/4 ID) pipe the rest of the way.
?
Click to expand...

+1
congrats on the new system
and a good price too
 
You must log in or register to reply here.
Back
Top