Jump to content
SAU Community

Exhaust Banging

Kozeyekan

By Kozeyekan,
in General Maintenance

 Share

Recommended Posts

Kozeyekan Proficient

Kozeyekan

Posted
Posted

Hey everyone

I've installed a 3 inch turbo back HKS silent system, and going downhill, it's all sweet, but uphill it bangs against the chassis just near the B pillar. Just wondering if anyone else has had this issue, I was thinking of getting a brace fabricated somehow, but am not sure where to attach it. I might need to go to a workshop and have them do it, but I was just wondering if anyone else has come across this, or is it just one of those things?

Link to comment
https://www.sau.com.au/forums/topic/132603-exhaust-banging/
Share on other sites
Godzilla32 Veteran

Godzilla32

Posted
Posted
Hey everyone

I've installed a 3 inch turbo back HKS silent system, and going downhill, it's all sweet, but uphill it bangs against the chassis just near the B pillar. Just wondering if anyone else has had this issue, I was thinking of getting a brace fabricated somehow, but am not sure where to attach it. I might need to go to a workshop and have them do it, but I was just wondering if anyone else has come across this, or is it just one of those things?

Why does it make a difference if your going up or down a hill? The exhaust hangers/rubbers should be holding it secure enough that it doesnt move so much to hit any part of the car. Id be checking that you have hooked all them up first and all the rubbers are in good condition before making any mods to the 'bolt on exhaust'...

Deren

Link to comment
https://www.sau.com.au/forums/topic/132603-exhaust-banging/#findComment-2457557
Share on other sites
cowie165 Veteran

cowie165

Posted
Posted

Are you sure the exhaust bolts are still tight? If they weren't torqued correctly perhaps one or two have loosened enough so that there is a little play in the dump->front section? On downhill it rests against itself but uphill it is just hanging and banging around as the car goes over bumps etc.?

I'd doublecheck that everything is tightened, and as Deren said, hangers are on and ok, before coughing up your hard earned for a brace. If it is on right, it shouldn't need an extra brace.

Link to comment
https://www.sau.com.au/forums/topic/132603-exhaust-banging/#findComment-2457602
Share on other sites
RANDY Veteran

RANDY

Posted
Posted

Might want to check that whoever fitted it used the factory hangar for the cat. There is an upside-down U shape that is bolted around the B-pillar. That goes on the outside of the cat, and the bolts that hold the cat to the dump/front pipe run through the holes in this hangar. It takes the weight of the dump/front pipe off the turbo, so if it's swinging around then i'd guess that it's not there, or not done up.

Check it, cause without it you can warp or crack your turbo flange or exhaust manifold. (whichever breaks first I guess)

Link to comment
https://www.sau.com.au/forums/topic/132603-exhaust-banging/#findComment-2457821
Share on other sites
Kozeyekan Proficient

Kozeyekan

Posted
  • Author
Posted

Hey guys, thanks for the advice, but:

The bolts are tight. Damn tight.

All the rubbers are in, the two at the rear, and the one on the side. The brace near the cat is on, and I might be able to adjust it enough to clear the b pillar brace. I'm giving it a go tomorrow.

The problem is that the b pillar area is a fair way from the cat. I was really hoping I'd missed a mounting point somewhere around that area that would bring it down about 2 cm, but apparantly not.

Link to comment
https://www.sau.com.au/forums/topic/132603-exhaust-banging/#findComment-2458008
Share on other sites
Godzilla32 Veteran

Godzilla32

Posted
Posted

I wouldnt be modifying an exhaust that is mean't to fit perfectly without any changes myself. Defeats the whole purpose of buying the bolt on exhaust option in the first place... There has to be another explanation for why its knocking on the cross member or watever its hitting.. It can be hard to see without a hoist and getting under it properly and checking from all angles.

Link to comment
https://www.sau.com.au/forums/topic/132603-exhaust-banging/#findComment-2458543
Share on other sites
Kozeyekan Proficient

Kozeyekan

Posted
  • Author
Posted
I wouldnt be modifying an exhaust that is mean't to fit perfectly without any changes myself. Defeats the whole purpose of buying the bolt on exhaust option in the first place... There has to be another explanation for why its knocking on the cross member or watever its hitting.. It can be hard to see without a hoist and getting under it properly and checking from all angles.

Yeah, I jacked it up and checked it all out.

The cat brace is kosher, the problem seems to be the rubbers.

They are about 2 inches long, and should be about 3. This would allow the exhaust to drop a bit lower, but the solid rubber would prevent the rebound which is causing the knock.

I'll check out some suppliers and see if I can organise these, Has anyone else had anything like this before?

Link to comment
https://www.sau.com.au/forums/topic/132603-exhaust-banging/#findComment-2458826
Share on other sites
Kozeyekan Proficient

Kozeyekan

Posted
  • Author
Posted
i have the problem with the exhaust hitting on the tub when i go around right hand corners. i found it was the front pipe twisting on the dump. also the fact that it is a 3.5".

I've got a solid front/dump pipe in one.

It does seem like it could move to the drivers side though. I'm going to try the rubbers, if that does not work, I'm going to have to cut a wedge out of the pipe and reweld to improve the angle.

Link to comment
https://www.sau.com.au/forums/topic/132603-exhaust-banging/#findComment-2460242
Share on other sites
MANWHORE Grand Master

MANWHORE

Posted
Posted

It's not as simple as you said. Of course the catback is supposed to bolt straight on. Mine did.

But when you start changing things upstream, like the cat, dump/front pipe, they can move the position of the catback slightly.

It moved mine about 1cm. If you think about it, the slightest difference in angle can move the catback quite a bit, since the catback is so long.

That 1cm was enough for it to bang.

In a perfect world, yes, everythign bolt on won't require mods. But, as i'm sure you're aware if you try and install things yourself, nothing ever 'bolts straight on' e.g. take a fmic kit as an example.

Cheers

Link to comment
https://www.sau.com.au/forums/topic/132603-exhaust-banging/#findComment-2460295
Share on other sites
Godzilla32 Veteran

Godzilla32

Posted
Posted
It's not as simple as you said. Of course the catback is supposed to bolt straight on. Mine did.

But when you start changing things upstream, like the cat, dump/front pipe, they can move the position of the catback slightly.

It moved mine about 1cm. If you think about it, the slightest difference in angle can move the catback quite a bit, since the catback is so long.

That 1cm was enough for it to bang.

In a perfect world, yes, everythign bolt on won't require mods. But, as i'm sure you're aware if you try and install things yourself, nothing ever 'bolts straight on' e.g. take a fmic kit as an example.

Cheers

Yeah clearly it comes down to compatibilty of various parts made by different companies.

Deren

Link to comment
https://www.sau.com.au/forums/topic/132603-exhaust-banging/#findComment-2462177
Share on other sites
Kozeyekan Proficient

Kozeyekan

Posted
  • Author
Posted

Well, the cat back is an HKS hipower silent, made specifically for the HNR?HCR-32, but the front/dump and cat were from BOS group buy. It seems all sweet, but I guess it's out by a few mm. Not that I'm complaining, the pipe looks fantastic, and is well made, it just means I'll have to fabricate a bracket, or find some way to make it work.

Link to comment
https://www.sau.com.au/forums/topic/132603-exhaust-banging/#findComment-2465473
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • MBS206
      R34 25GT Engine Light 21

      By MBS206 · Posted

      Take the value it measured as, and pick the closest range available that is above the reading on the screen.   Also, no point just testing the coils. Read what has been said again. You need to test all your wiring, everything.
    • GTSBoy
      R34 Handbrake light saying ON and intermittently flashing

      By GTSBoy · Posted

      Does the scanner do all the CUs in the car, or only the ECU?
    • albyz34gt
      R34 N/a And R34 Turbo (gtt) Transmission.. Uh, Problem.

      By albyz34gt · Posted

      @666DAN sorry to bring you and old thread.     I've got my de+t done and it's all running great other than 1 small issue.    Car has remained auto with the na auto and tcm, I've used a stagea ecu with. NIstune board and everything is great other than my gear selection on the dash. It illuminates park, reverse, neutral, 3rd and 2nd when selected . But nothing when in  drive or what gear your in when you pop it into tiptronic. I'm sure there is maybe 1 wire in the ecu plug I need to move to rectify this. Do ya have any ideas?     Cheers man
    • RB25inside
      R34 Handbrake light saying ON and intermittently flashing

      By RB25inside · Posted

      Well I recently changed my rear axles and was thinking if I bumped anything, I have been driving the car for a while now though... But it has been raining today so everything is wet under the wheel arches. Brakes feel fine and can't hear any of the metal screamers, I had a squeak coming from one of the handbrake drums but that seems to have gone away a while ago. I was going down a hill when it lit up and I did feel the abs bite for a second and question why it did it?
    • GTSBoy
      ECU sees many times the speed than speedo does (R34 swap)

      By GTSBoy · Posted

      Correct. Um. I dunno. I haven't cared enough about the way that the NA cars work to know for sure. But..... The 33/34 turbo manual cars have an electronic speed sensor in the gearbox that outputs a +/- (ie, sawtooth AC) voltage signal. That is connected to the speedo. The speedo then outputs a 0-5v square wave (ie, PWM) signal that the ECU (and any other CU on the bus) sees. The speed sensor is NOT directly connected to the ECU. So here's the problem. Your new ECU expects to see the PWM signal, but must somehow be getting a direct signal from the diff speed sensor. Which would suggest that the wiring of the NA car is not the same as the turbo cars. I think you will need to spend some time with (hopefully the wiring diagram for the car) and a multimeter to see what is connected to what. Then, presuming I am correct**, you would then want to separate the ECU speed signal input from the rest of the car's wiring, and probably either buy a speed signal converter, or build one using an arduino (or similar). That would take in the speed sensor signal and output a scaled (and suitably rearranged) signal for the ECU. ** We shouldn't presume that I am correct here, because there might be something else crazy going on. I don't think you could convert the speedo to be fed from the gearbox sensor, because the pulse rate from that sensor is probably different to the diff sensor and then the speedo would read wrongly. And this also wouldn't fix the ECU's problem either, because the ECU doesn't want to see the gearbox signal direct either (assuming that they are all on the same wiring, for some odd NA related reason, see above caveat!) Does this help? Probably not. Can you make it work? Almost certainly. With the above work. You should buy a handheld oscilloscope from Aliexpress so that you can view these signals directly. Connect up the probes and drive the car. Show photos of the screen when drving at known speeds and connected to different places, and we'll see what we can learn about it.
×
×
  • Create New...