To those who own NISMO motor mounts & a header: Please help!

[jtsarnak]

I recently rebuilt my KA and because the NISMO mounts were the same price as normal OEMs, I opted for those. I also had a Hotshot Header on before I pulled the engine.

Since replacing the motor mounts, the engine sits higher, making the header pipe sit millimeters from the footwell by the pedals. Not only is it melting the rubber mat I have, it's causing awful vibration in the car because the header is either sitting against the footwell or knocking against it when accelerating.

Did anyone have this problem with the Nismo mounts/header combination and find a reasonable resolution to it? I really want to keep the header but if I can't find a way to make it sit a few inches below the footwell, I'll have to go back to a normal manifold. Please help!

[Silvia007]

The awful vibration is mostly from the stiffened NISMO mounts. For you headers, I'd use exhaust wrap to wrap the whole header. Works great at keeping the temps down. I don't think the Nismo mounts make the engine **** higher. If it does, somethings wrong. For the clearance, what headers do you have? I'd worry about it once you hear knocking such as in the case of the headers hitting your foot well.

[jtsarnak]

The headers are hotshot. There is vibration (more of a low hum) from the increased stiffness of the mounts. I expected that. There is also a more knocking vibration (the vibration I want to rid myself of) from the header hitting the footwell.

The mounts are known to make the engine sit a bit higher because they are stiffer and don't compress as much under the weight of the engine. I've heard people claim their strut tower bars don't clear anymore, etc.

So again, if anyone has any remedies to this situation let me know. (header wrap is not really an option because it won't change the fact that the header is so close to the footwell so it will still knock, just might be dampened a little by the wrap itself).

[JNM240]

One of the two Nismo motor mouts is actually 1/2" taller than the OE mount. Therefore, the motor sits 1/2" higher on that side (split the difference, it will sit 1/4" higher in the middle of the motor). IIRC it was the passanger side mount that sat taller on my SOHC, and that made it so where i could not use a strut tower brace. It was NOT because my OE mounts were blown, worn out, deteoriated, ect. I actually have pictures of the OE next to the Nismo. Nismos are taller.

Only thing i can say is go back to OE. Or deal with the rattling noise.

[jtsarnak]

Going back to OE is an option, albeit a very time intensive one (disconnecting the trans, hoses, some accessories then putting everything back together is a lot).

I was wondering if anyone tried bending the header pipe so that it angled down futher before leveling out again to give it more clearance?

Or cutting the pipe and welding a small extension in to make it sit further down?

Any other ideas?

[JNM240]

THAT is time consuming. Just take a BFH (big F#!^$% hammer) and indent the floor board where it is rattling against.

[Silvia007]

Hmm... wonder why nismo mounts sit higher. My Cusco mounts does not affect height at all. Anyway, if going back to stockers is not an option, I'd say the easiest thing to do is like you suggested, cut and weld a extension to the headers.

[Soulja]

While its still connected to the cat, I would loosen the bolts attaching tha manifled to the head. You might be able to shift the header on the head a slight amount, giving you a couple more mm's of clearance. You could bang the floorboard up a little with a hammer, or you could try torching the header and bending it a slight bit for some more clearance. I would still wrap the header in exhaust tape anyway, it will cut down on the heat, and increase the efficiency of the header. Or you could fill your old mounts with urethane or window weld and swap them in after it cures. And you shouldn't need to disconnect everything to swap out the mounts, just unbolt the engine and trans mount, jack the engine up enough to remove it.

[jtsarnak]

As a side note, which exhaust tape/header wrap do you guys find effective and where's a good place to get some? How much would i need to do a hotshot header?

[p00t]

I have stock header and custom exhaust. I had the exhaust done before the nismo mounts and after installing the mounts the exhaust would not pull up properly to the header.

I didnt have clearance issues with the stock header, sounds like jwt was alittle laid back with their clearances.

I had to have the end of the header modified to meet up with the exhaust properly again. It wound up being angled alittle differently and about 1/2-1" longer.

I know you dont want to cut up your nice header but instead of banging out the floorboards you should really have the exhaust fixed, it sounds like it may be too close in other areas as well. The exhaust being too close or touching the floor boards will result in them rusting at a much faster rate then normal, and a potential fire hazard.