TD04 Hard Pipe and/or FMIC Surge Issue Thread

**CoopKill** · 03-07-2012, 10:38 PM

If you have any input, or fixes, PLEASE post up!

As the title suggests this is an issue when adding hard pipes to a TD04 turbo. Some people will tell you that this is a FMIC issue, but that is only a piece of the story, as the FMIC have hard pipes as well.

This started when I installed DNP hard pipe kit on my BPU VR4. Was not real bad, and I thought at the time it was an issue with my HKS BOV. Well I was wrong. I switched to a Greddy BOV with no change.

I bought and installed the ETS FMIC, and the problem got somewhat worse, as in the length of load area increased when it surges.

I have been researching this for about a year, asking question, and annoying anyone that would stand still to listen. I got a lot of "Install a balance tube, and be done with it" from many people. The problem is the balance tube fix rarely works from what I have found in my quest. Not to mention quite a task to get it installed.

About 6 months ago I was chatting with Chris (ABM) and he told me basically I had 3 options.

1) Install larger turbos so the power band is higher up in the rpm range.
2) Install a balance tube, which is a 50/50 shot of any effect.
3) Install a separator in the merge pipe just before the fmic.
3.5) Quite being a puss and drive around it!

Well 3.5 got old quick, and another gentleman on the other site installed the separator in the merge pipe, and reported it helped a bunch.

This got me off my ass to actually do something.'Sooooo...

I was going to take the merge pipe to ETS to do this, but I was off my ass anyway.

So I decided to do this on my own instead of having ETS tackle it. I will give you the bottom line first, then show you what I did.

Bottom Line:

It did not rid me of the surging. It did however shorten the load, and length of load area that it surges. This does help the ability to drive around the issue a lot. Not sure if it has anything to do with what I did, but the car is pulling more consistently from 4000-6500 rpm.

I will be traveling about 3hrs Saturday to go AutoX, so I will get a real chance to see the results on the freeway. One last thing before I get to the pics of what I did. I only surge after the car warms up. It does not do it at all while cool...

I decided to not cut it in half, as I thought it not necessary, and a lot more welding work to do so I used cardboard to template the inside of the merge pipe.

Used a decent size piece of steel.

Ground the powder coat off, drilled holes, spot welded, ground smooth, and painted.

Was this worth the effort? At this point I believe it is. I will know more after this weekend with the 6hrs of driving, and day of AutoX...

**CoreyB** · 03-07-2012, 10:49 PM

All that work and all it is, is a faulty engine temp sensor.

**CoopKill** · 03-07-2012, 11:34 PM

Temp sensor is fine, this is a known issue on most that run similar.

**CoopKill** · 03-07-2012, 11:34 PM

A reply about this:

Posted by SnakeSkinner:

I think It really needs to be Extended out past the end of the pipe and into the intercooler to be fully effective. To the point were it goes from being a 3" pipe to expanding out to a end tank.