Header problem

[Ed]

You know after reading your original post again I find that my original answer was a bit off. Sorry, I miss understood you. I had my exhaust custom made from the header back.

[Fun_in_my_z]

Those glass packs will sound real nice.....untill you get them hot then run through some water. Hot glass and cold water dont mix.

[240ZMan]

Originally posted by Ed

You know after reading your original post again I find that my original answer was a bit off. Sorry, I miss understood you. I had my exhaust custom made from the header back.

No worries, Ed. If I were to do this again, I'd go the route you did. I just don't think it's likely that a bolt-on exhaust system is going to fit a 30+ year old car. Probably would have been easier to do a custom from the header back from the start.

[Sean240Z]

I just installed my MSA 6 into 1 header and had the same transmission mount interference problem. Did Ken ever post a picture of his fix (i.e. cutting and welding the pipe just behind the collector)? If not, Ken, could you please send me / post a pic of your solution?

I'm a little ticked off at MSA :mad: . This problem was identified by 240ZMan at least six months ago, and MSA is still selling the defective headers. I have a call into MSA right now. When I get a response / resolution, I'll post the results.

Cheers,

[dhoneycutt]

I called them and they said it was not a problem with the header but my car.

Go figure. Another member here on the site was told that the vendor making the header had a defective jig (or something close to that) and got a new header sent to him. When I told MSA that, they just said that they sold hundreds of them and never had a problem. I will make neccessary modifications and be done with it. To MSA's credit however, I did mess up one of the pipes and they sent me a new one at no expense to me.

[Sean240Z]

To give you a final update on my situation, I spoke with Kurt at Motorsport and he told me the same thing as reported by 240ZMan (i.e. a problem with the manufacturer's jig). At first he wanted me to pull the entire exhaust off my car and Motorsport would pay to ship it back to California. They would then send me a properly configured exhaust system. As this car is my daily driver, this would not work for me. So I proposed that I take my 240Z to a muffler shop and get an estimate to fix the problem, and that Motorsport would pay.

Yesterday, I got the quote (~$80) and Motorsport agreed to reimburse my credit card. I'll be taking my car in on Saturday to get the section of pipe after the collector replaced. I'm still a little ticked that Motorsport sold me a "bolt on exhaust system" that didn't fit properly especially when this issue was previously identified to Motorsport, but overall, I'm satisfied with their customer service to "make it right".

If I had to do this again, I would buy the header from Motorsport and get a good local muffler shop to build a custom exhaust for me. My problem is, that being in the military, I move so often that it is difficult to find a "good" muffler shop or garage. Ironically, I finally found what appears to be a very good muffler shop after I had already purchased and installed my Motorsport exhaust system (Majic Muffler in Fort Walton Beach - specializes in custom exhaust for drag cars and often dynos a number of systems before coming up with his final design for a race application. The owner kept stressing to me the importance of quality work and how his business was built upon his reputation).

In summary, the final system I'll have in place after Saturday's tweaks will be:

Motorsport 6-into-1 coated header

- 2.5" mandrel bent alluminized steel exhaust

- Dynomax Ultraflow SS muffler (WLK-17283) http://store.summitracing.com/

http://www.dynomax.com/ultrafloss.stm

- Dynomax Bullet Race Muffler (WLK-24236) http://store.summitracing.com/

- Dynomax Stainless Steel band clamp (slip joint) (WLK-33226) http://store.summitracing.com/

- Dynomax Stainless Steel band clamp (butt joint) (WLK-33240) http://store.summitracing.com/

NOTE: I decided not to use the Dynomax "Turbo" muffler (http://www.dynomax.com/superturbo.stm) that came with the Motorsport alluminized exhaust system and go with the straight through Ultraflow (410 CFM vs 1000 CFM).

My current engine config is as follows:

L28 (F-54 block, P-79 head)

Schnieder Stage 2 Cam

no head work

Previous to my exhaust upgrade, I had a Motorsport 3-into-2 header, not coated but wrapped with header tape, a 2.25" shop bent (i.e. not mandrel bent) exhaust system and a "Flo Pro" performance muffler.

NOTE: I would definitely not recommend wrapping your uncoated header. My header was only four years old and it rusted through and had a dime sized hole in one of the pipes. This occured with storing my car in sub-zero temps for probably five months of the year!

With my previous system the car performed very well. I never dyno'd my car or took it to the drag strip but a drag racing friend told my it felt like a low 14 second car and I was able to stay with another friends mostly stock 300ZX TT up to approx 130 mph (don't ask!). (FYI: 5-speed with 3.9 R200)

I've been driving my 240Z for the last week with the new header, 2.5" exhaust (yes, with the pipe contacting the transmission mount) and just the Ultraflow muffler installed (i.e. no race bullet muffler). In this config, my car does not appear to have lost any bottom end grunt and now REALLY pulls hard from 3,500 RPM on up. In its current config, the exhaust has a deep rumble at idle, but gets buzzy (dare I say RICEY) from 2,000 - 2,500 RPM. I'm hoping the bullet race style muffler just aft of the transmission mount will reduce the resonance. Once I have my system in its final config, I'll post a final message.

Finally, this forum is awesome. I like to research any upgrades I make to my car before I spend my hard earned cash. I've got to say that the advice and suggestions of those of you who regularly contribute to this forum is invaluable. Thank you for sharing your knowledge.

Cheers,

[Sean240Z]

Two weeks ago I finally got my reworked exhaust installed with the Dynomax Bullet Race muffler installed. The final configuration sounds awesome. The installation of the bullet muffler really reduced the resonance and significantly quieted down the exhaust. There is still some resonance but it seems to have moved down the rev range to approx. 1600 RPM and narrowed the resonance from a ~500 RPM band to a 100 RPM band.

One additional finding was that even with the ceramic coating, after idling at a drive-thru for 10 minutes, the underhood temperature was enough to cause a vapour lock problem (i.e. a miss with the engine under load). The main problem is that the 6-into-1 header puts one of the header pipes about five inches under the rear float bowl. I ended up re-wrapping the fuel lines with insulation (similar to the OEM insulation) and building an extended heat shield under the rear carb float bowl. It appears that the wrap and heat shield have done the trick and I no longer have the vapour lock problem.

Cheers,

[jmark]

Sean I just got through with a similar fix. The Z sounds alot better now. Sal at MSA did reimburse me the $100 it took to get the system to work. The Dynomax Bullet makes a big difference in the noise/boominess.

[dhoneycutt]

Sean240z...Do you have any pictures of the system installed? I just moved a couple of months ago to Iowa and have to find a good exhaust shop that could do the work for me. I would like to get some pictures of what you guys did to fix the problem so I know what others did vs. what I am thinking about doing. Thanks in advance.

[Sean240Z]

dhoneycutt:

As requested, I have posted images of my final exhaust configuration to My Gallery.

My Gallery

If you have any questions drop me a line.

Cheers,

[jackboxxx]

Sean I just got through with a similar fix. The Z sounds alot better now. Sal at MSA did reimburse me the $100 it took to get the system to work. The Dynomax Bullet makes a big difference in the noise/boominess.

Sal's a good guy , and the couple of problems ive had with defective or damaged parts over the years he has always fixxed the problem promptly.

DISCLAIMER:

(jackboxxx is not affiliated with MSA. just a happy customer.)

[bajcsi]

Has anyone looked at what our cars might have in common? I ask this because I am having this problem right now. There has to be something to cause this that is common to our builds or cars because previously my car's setup was a stock L28 with N42 head and the MSA 6->1 header (round port).

While I have changed many things (read most of) about the car, the things of import that have changed and could have affected dimensions are: the transmission mount is new, the motor mounts are new and I have an E31 head instead of the original N42.

At this point I have tried not one but TWO 6->1 headers (square port). One was ceramic coated header from 2002ish and one was a ceramic coated from after the redesign. Both fit identically; which is to say both cause interference with the transmission mount. As well, I'm trying to bolt up the MSA Premium Exhaust for the 6->1 header.

Now... Are the dimensions for port locations on an E31 head different from an N42? Has anyone changed their heads or have this head? Has anyone replaced their motor mounts and/or transmission mounts? I measured the motor mounts and they appear to be identical. However, I don't have my OLD transmission mount. Is it possible the replacement ones that we get now from MSA and Nissan are taller? If so this would change the angle of both the tranny (and by extension engine and all things attached to it)?

I ask because I'd rather find and possibly fix the root cause of the problem than cut up a perfectly good exhaust and simply work around symptoms.

Thanks guys...

Brett