Since the first day I went WOT I've heard a low thumping tone from when boost kicks in until I shift. Today I drove the car in 4th gear at 6000 rpms and it wasn't doing it. As soon as I punched it you could hear the thumping.

Any ideas?

Kris

i had this issue with my previous car - moded 180SX, it had turbo upgrade and all bolt-ons you name it, it was cutting boost on me at midrange and couldn`t figure out why. Did all the boost leak test and tuning but still cutting on me. Until I rolled on dyno and could actually see the oem rubber intake elbow collapse when boosting. Got myself a custom intake inlet pipe and fixed the problem.

this time around on the Evo, i bought the Blitz aluminum inlet pipe so this won`t happen.

i had this issue with my previous car - moded 180SX, it had turbo upgrade and all bolt-ons you name it, it was cutting boost on me at midrange and couldn`t figure out why. Did all the boost leak test and tuning but still cutting on me. Until I rolled on dyno and could actually see the oem rubber intake elbow collapse when boosting. Got myself a custom intake inlet pipe and fixed the problem.

this time around on the Evo, i bought the Blitz aluminum inlet pipe so this won`t happen.

Did you ever notice it with the Evo?

I've heard of this with certain intakes on the SRT-4. I'll have to search their for a video.

It seems to only happen at WOT. I'll also download the update for the A/P and see what kind of boost I'm getting when it happens.

Thanks!
Kris

Since the first day I went WOT I've heard a low thumping tone from when boost kicks in until I shift. Today I drove the car in 4th gear at 6000 rpms and it wasn't doing it. As soon as I punched it you could hear the thumping.

Any ideas?

Kris

I am pretty sure this has been covered before and our intakes have carbon steel spiral wound in the rubber to keep it from colapsing. Also when you say a thumping sound is it followed by the car jerking or power cutting out? Is it a consistant thump?

I am pretty sure this has been covered before and our intakes have carbon steel spiral wound in the rubber to keep it from colapsing. Also when you say a thumping sound is it followed by the car jerking or power cutting out? Is it a consistant thump?

I can squeeze it by hand pretty easily

http://www.youtube.com/watch?v=Moai7Y_bl8w

Yes it is consistent at the same RPM's, only at WOT and in all gears.

Kris

And no the car doesn't jerk or studder it just keeps accelerating.

Kris

If it were colapsing your car would experience cut out from the intake sucking shut.
Try something like taking a zip tie, or a couple of them put together around your intake hose. Tighten them around something like a paper clip (or something else small but that has some weight) Make sure to zip it tightly. Once it is zipped up tight take a magic marker and put a small line on each side of the zip tie. Then take the car out for a quick drive to see if you can get the car to do the thumping. Once you do pull over and see if the zip tie and or paper clip has moved. If the paper clip is gone then the intake is colapsing, if the zip tie has moved out side the lines its probably colapsing alot.

DOes this make sense?

I wondered about this for the evo. I had that problem with my AEM intake on the srt, so now I steer clear of any intake that has a 60 or more degree of silicone hose.

If it were colapsing your car would experience cut out from the intake sucking shut.
Try something like taking a zip tie, or a couple of them put together around your intake hose. Tighten them around something like a paper clip (or something else small but that has some weight) Make sure to zip it tightly. Once it is zipped up tight take a magic marker and put a small line on each side of the zip tie. Then take the car out for a quick drive to see if you can get the car to do the thumping. Once you do pull over and see if the zip tie and or paper clip has moved. If the paper clip is gone then the intake is colapsing, if the zip tie has moved out side the lines its probably colapsing alot.

DOes this make sense?

Yeah it does. I'll take it out and try it. I'm boosting 21 psi then dropping to 17 at redline'ish. I'll try that tomorrow.

@boostin20-I have the AEM shortram on my srt-4 and it's always held up. I heard the KnN model does collapse.

It's just too strange...


Kris