Stroker M20 exhaust

[digger]

Do you still have the pictures from this thread since photobucket caught the lame?

i updated the ones i had

[vehicular]

Do you still have the pictures from this thread since photobucket caught the lame?

[SNEAK413]

Any word on the dyno with your new exhaust?

[digger]

Hey digger any updates on this?

getting a tune next week ( fingers crossed) so should see final gains in a week or so. just had so many issues to deal with because of incompetent people working on my car stuffing things up.....

[Bimmer_man]

Hey digger any updates on this?

[digger]

i have moved the X-pipe from 4th to 3rd harmonic and it seems a positive move.

The AFR or timing has not been adjusted at all and you can see that the engine runs alot leaner in parts now and make alot more power in midrange as i was hoping and no loss of topend hp.

i will get it properly tuned in the next couple of weeks and will update as i imagine there will be some additional gains from a tune



im not sure why the operator ran it from such a low rpm but 100km/h is 3400rpm so the peak torque is 220twq 4200rpm give or take and hp 224whp 6100rpm.

[digger]

two vibrant bottle style resonators which are similar to what i have now and my current muffler which was a custom one made by walker

[MaxBell]

Any progress on this? Have you decided what you're doing for resonator/muffler in the center?

I just ordered all mine and went Borla ProXS in the middle, Stromung at the back.

[digger]

Agreed ^^^ i have bav auto headers straight through to the muffler. It's pretty raspy. I'm waiting to see what digger does before i change anything :)

I've decided to just move the X-pipe (a better X-pipe will be used though) and retain twin system but ill be redoing some of the hacked piping etc. i wanted to retain my custom rear muffler as i liked the sound of a twin system.

i do believe a single 3" or even slightly smaller 2.75" (hard to find cats, mufflers) would be better for absolute best for performance, and simplicity, weight, cost etc if starting from scratch but maybe another day.....

[tinkerputzer]

Agreed ^^^ i have bav auto headers straight through to the muffler. It's pretty raspy. I'm waiting to see what digger does before i change anything :)

[LJ851]

Would there be any negative effects if the pipes aren't crossed?

My car is currently like this, it does not sound good in my opinion.

[digger]

Would there be any negative effects if the pipes aren't crossed?

I can’t say if having no merge at all is an issue as I have not done any tests. I have seen it done and from memory Stuck did this with his M20 and it seemed to work out well. Unless you do a test with a merge and another without a merge you won’t really know the effect of this alone.

Personally I would put a cross over or merge of some sort such as an X-pipe, Y-pipe or H-pipe. BMW usually does this about midway down just behind the gearbox on the 6cyl engines which is seems to give a good allround power curve.

If you were significantly different from stock it might respond to something different but You would need to do a test if you want to better this.

[AWDBOB]

the vibrant bullet style resonators are quite cheap, the ultra quiet are large OD so clearance is an issue on a lowered car.

Would there be any negative effects if the pipes aren't crossed?

[digger]

the vibrant bullet style resonators are quite cheap, the ultra quiet are large OD so clearance is an issue on a lowered car.

[Bullhead]

I have heard of a lot of people using the dynomax ultra bullet muffler for resonators. I am either going this route or using an old school resonator like a glasspack but this is just to save funds. The vibrant resonators aren't cheap but if you have the $ it's a great setup.