Bisimoto Pulse Chamber fit ?

[trond]

I received my Bisimoto Pulse chamber 'muffler' some time ago, then deciding I wanted to run it with a cat I had to wait until last week to fit the new setup on my 80SC. Much to my disappointment I can not find any way to fit it to my car without cutting&welding. Either I need to cut and re-angle the exhaust or I need to modify the bodywork. Same issue with both stock cat and with the cat bypass pipe. I tried loosening and re-angling all connections but no luck. As a comparison I had 4 different mufflers on the car over the years with tailpipe always dead centered in the cutout so nothing wrong with the car geometry. What is the fix ? I hesitate to cut in the cars bodywork

Thankful for any advice

[shoooo32]

Have you tried reaching out to Bisi? They stand behind their products and should be able to solve this issue without you having to bust out the welder...

[douglas bray]

Any chance you own a cab and had your engine propped up on a jack? I stood over Bisi watching the blood drain from his face when we first test-fit my pulse chamber. We had lifted the car up to make installing it a little easier and had the same issue..... forgetting that the engine moves a bit more on a cabriolet than on a coupe.

[Bisimoto]

Trond, I can take care of you, if there is some misalignment. Kindly write to me at Bisi@bisimoto.com, or pm me you email address. Cheers.

[Bisimoto]

Rich, you purchased a pre production prototype, which is not the same as the OP. You and I also had conversations about the pros and cons of the setup, and came to amends.
My offer to you still stands.

[Rich Gas]

Easiest way around this production "anomaly" would be a 2" thick exhaust spacer (2.5-3" ID).

[Rich Gas]

[trond]

Rich; such a spacer might make it fit on my car. How did you make that ? I wonder what happened in the fabrication process....

[Rich Gas]

Trond, I used a Corvette heat riser valve to control noise, but it happened to be the perfect spacer width also. It's a chunk of metal so I made a rudimentary heat sink out of it as well. You need to bore the mounting holes a little, otherwise the valve will bind.
Amazon also sells a blank spacer for this valve, which is probably what you want if you're satisfied with the sound.

[trond]

bisimoto; I did send you my e-mail yesterday. Awaiting your response

[trond]

Shows pulsechamber interferes with bodywork both rear of cutout and also front of cutout. In the pictures it is about 1 inch low (will not fit in the cutout any higher up) and held onto the exhaust flange with vicegrips
Seems to me a 2" spacer will not do the job

[Rich Gas]

The Corvette heat riser works... The sound is awesome once installed.

With heat riser...


Without....

[Rich Gas]

Mock up a spacer starting at 2" with cardboard or pvc pipe, see how the angles change etc...move to 2.5"-4" etc. Remember, I did cut my lower valance, but a proper spacer should do the trick.

Cut without heat riser....very tight fit...

[trond]

the geometry seem to be different on my item. On the pictures from my car the upper one) the pulse chamber is firmly contacting the bodywork BOTH sides of the cutout! As if the angle out is not right AND it is too short. If I add a 2" spacer it will clear the front piece (front of cutout) but I would need to remove a lot from the bumper valence. weird

As mentioned any other muffler fits perfect, with tailpipe dead center of cutout so nothing strange with geometry of the car.

[Rich Gas]

Weird is right. I probably got yours, and you got mine. Carrera and SC difference. I'm running a FabSpeed sport Cat also. My stock muffler was dead center.

The Pulse Chamber does have awesome sound if you can get it working.

[trond]

I was not aware of any carrera vs SC difference ? To me the SC is cooler obviously but apart from that the geometry of all related parts identical. I found no difference with original cat vs cat bypass and if yours and mine stock mufflers fit perfect then this argument on possible differences in geometry/lenghts is clearly BS. The only conclusion is their QC must be questionable. Unfortunately they seem to be reluctant to relate to that. No response since I raised the issue with them on Sept 2nd. I am starting to get seriously annoyed

[Elombard]

Trond I think the problem might be that I think you are running an aftermarket cat delete that is not stock length or something.

[trond]

no, definitely not the problem. The cat delete is EXACTLY same length as stock cat. I get the same result with stock cat. And with either the stock muffler hits spot on dead center of cutout.

Anyway I got some good advice from Rich gas and now I just need to decide if I want to cut rear valence or not. Hurts me to do so

[Rich Gas]

Thanks trond. I was/still a little upset that I had to cut my car, but I was so excited I couldn't help myself. My wife was going WTF are you doing to your pristine car. Ah, nothing. Anyway, lower valances are cheap...mothers and young children will faint, grown men will cry, and the ladies will want a ride when you drive by with the Pulse Chamber! Guaranteed.

[Rawknees'Turbo]

^^^

You girly men that fret about cutting on the cars need to grow some pairs - jeebuz, you'd think these things were mermaids, unicorns or the cure to cancer !!!