R33 + Nismo Exhaust Bumping Tailshaft

[SargeRX8]

Ive got a little issue. Ive noticed a strange ting ting ting sound from underneath the vehicle when taking a turn with more than usual speed(not speeding just a fast turn). The exhaust is moving just 2mm, enough to ting and touch the tailshaft. It took a while to pinpoint the issue. First it sounded like some shit hanging down from the car being dragged behind me, like a sheet of metal scraping on concrete. Then it changed to a hollow sound of a screw driver tapping the exhaust. I looked for anything loose, I looked for contact anywhere and nothing. Finally I pulled off the exhaust and threw on my HKS and took the same turns with the same speed and there is no contact. The noise is gone.

Does anyone else have this kind of issue? I am using all hangers for the exhaust bar one because its a f**king pain in the ass to get back in and I'm lazy but if need be I'll do it. Would it be stupid to bash the resonator/muffler where it makes contact with the tailshaft? My HKS was having a similar issue where it would ting and bump the diff housing. I fixed this by wrapping rubber around the exhaust to dampen the sound and impact. I can't do that here because the tailshaft is spinning and it will probably just tear off what ever I put on the muffler. Its not the exhaust piping bumping, rather the big muffler in the middle of the Nismo exhaust.

Any ideas on how to proceed with this?

[CLNSKY]

Maybe get an exhaust stop to reweld the hanger. I had a similar issue before

[Victory]

From my experience it is important to have all of the hangers connected as it then stops the exhaust from rotating along its axis and rubbing on things - the tail shaft normally.

In my case this is compounded by the pipe being 100mm dia when it goes past the diff and there is very little clearance.

[mystery_kid]

just take it to an exhaust shop and tell them the problem, they will fabricate a new mount somewhere to fix the problem

[StevenCJR31]

From my experience it is important to have all of the hangers connected as it then stops the exhaust from rotating along its axis and rubbing on things - the tail shaft normally.

In my case this is compounded by the pipe being 100mm dia when it goes past the diff and there is very little clearance.

one of the (VERY) few drawbacks of IRS

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[SargeRX8]

Sorry for the bump but just to update. I have refitted the exhaust with all hangers mounted. It really feels like the whole exhaust is pulling to the right side of the car, you can see the hangers aren't hanging, they're being pulled. Since Ive recently fitted tighter suspension on the car, now moderate bumps are causing contact. There is about half a cm of clearance between the top of the muffler and the tailshaft. I can go to an exhaust shop but at the same time I don't think its meant to be sitting like that.

Where can I take the car to check if the whole engine is aligned correctly? I did the clutch on my car and to remove the gearbox I had to loosen the engine mounts so if there is even 1 or 2 mm of difference at the front, it will really show at the back. I don't think its meant to pull against the rubber mounts as it is. Its an aftermarket turbo, didn't require a spacer with a 3" dump and a 5" body venom cat. I think the problem can be fixed if I can get the angle of the exhaust inlet and cat outlet changed but this might be a bandaid fix.

Are there symptoms to a misaligned engine/gearbox? The car doesn't vibrate at all, but I don't feel I should have to apply force to the exhaust tip to have it sit straighter.

[GTR-N1]

On a former car where the hanger rubbers were aging, Repco allowed me to go through a whole assortment of boxes of rubber mounts until I found one that suited; and pulled the exhaust away from the tailshaft.

[StevenCJR31]

if the driveline is not vibrating from any possible misalignment then simply get the exhaust pipe rebent (!) ever so slightly to get the clearence you need

[Ben C34]

No way could it be misaligned.

[SargeRX8]

Yeah pretty silly thinking its the engine. Symptoms of a misaligned engine are pretty severe.

I'm gonna try the local exhaust shop, but they like to talk alot of shit. I go there say xyz they tell me abcdefghijklmnopqrstuvw and miss everything I say. Then the other local exhaust shop will tell me to come back in two weeks coz he is too busy.

Maybe I'll get a higher flowing mid muffler and have it welded in a shifted location. This exhaust does feel like abit of a restriction compared to the hks piece. I was suggested by someone to wrap the muffler with a rubber tape just to dampen the sound.

[StevenCJR31]

^^ not silly thinking at all, i broke BOTH the engine mounts on my datsun , i didnt (not even vibrating!)know it until the exhaust pipe was touching the body of the car (the engine/drivetrain moved to one side) NO other symptoms and it took me awhile to work out where the problem was

Edited August 11, 2013 by StevenCJR31

[StevenCJR31]

Yeah pretty silly thinking its the engine. Symptoms of a misaligned engine are pretty severe.

I'm gonna try the local exhaust shop, but they like to talk alot of shit. I go there say xyz they tell me abcdefghijklmnopqrstuvw and miss everything I say. Then the other local exhaust shop will tell me to come back in two weeks coz he is too busy.

Maybe I'll get a higher flowing mid muffler and have it welded in a shifted location. This exhaust does feel like abit of a restriction compared to the hks piece. I was suggested by someone to wrap the muffler with a rubber tape just to dampen the sound.

wrap the muffler with rubber tape? hope you have a fire extinguisher handy

[SargeRX8]

How do you check something like alignment is there a method of measuring in the engine bay? My hks has massive clearance and the stock exhaust clears fine its just this fat nismo. Wish I could hear how it would sound with the mid muffler removed and a straight pipe welded in place. That would sort the rattling issue. Its been almost 3 years since the clutch was done if the engine was misaligned something should have broken. I feel the reason for contact is the extra vibration passed through the chassis by the coilovers. I also dont know if the lowered height of the car could be affecting it.

[SargeRX8]

If anyone else has a Nismo exhaust on their R33 can you check if this is how your clearances look? I'm trying to determine if its the exhaust moving and hitting the tailshaft or if its the tailshaft hitting the exhaust and honestly I don't know now. The exhaust has very little up and down movement but has side to side. The tailshaft, around the middle support thing what ever its called, has some play in it, in all directions. If I give the exhaust a really good shake I can make it hit the tail shaft but I really can't see that type of force applied by bumps on the road.

In the third pic you can see the point of contact that dark patch is a clean patch where the tailshaft is hitting the muffler.

Does anyone know where I can buy the HKS hi power exhaust mid muffler section? Ive checked online and most are in the UK.

Edited August 20, 2013 by SargeRX8