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Yoshimura Comp or ProCircuit T4 exahust on 400E???

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Hey DRZers. 

     I have a question for those with the experience and knowledge.  I have two DRZ400Es('01 and '02). Both have full aftermarket exhausts with spark arrestors. The 2001 is street legal and the '02 is not, as of yet(fingers crossed), I'm in CA.  On the '01 it has a full Yoshimura Comp exhaust and I am wondering which set up better or the differences in performance characteristics.  I can't just jump on each bike to do testing as the '02 is not registered yet because I am attempting to get it street legal.  So I was wondering if anyone on here has first hand experience and knowledge of these two systems on these bikes. I want to take the best off both bikes and then sell off the other once the '02 is street legal.

    I will note that the Yoshimura system was probably put on the bike back in 2001-02 as the bike was fully set up for desert runs with ProCircuit Suspension tuning, Tokyo Mods Carb work(which was crap) and a Baja Kit light set up. I state this because the Yoshi system is old and must be straight from the designs they made for Mike Kiedrowski and Suzuki's eduro team.  Also, the header on the Yoshi is about 3cm larger on the OD than the T4.  Here are two photos of the Yoshi system.  The T4 muffler is significantly smaller in diameter and rides higher up next to the fender.

    I'm planning to make sure one of the bikes if fully buttoned up tight for a first time entry into the Barstow to Vegas race in November. weight is of some concern.

  Thanks guys!!! 

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Well the header is the major restriction in the exhaust system on these bikes, so I'd probably recommend the Yosh since it has the larger header. Do you have a stock E header to compare header diameters? From the factory, the E header is slightly larger than the S and SM headers, and most aftermarket exhaust headers are roughly the same size as the factory E. My guess is the T4 is smaller than the factory E header and would stifle performance.

Can you post pictures of the Pro Circuit setup?

Also, whats with that rear bracket on the Yosh muffler?

Edited by ptgarcia
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9 hours ago, cgreenbush said:

. weight is of some concern.

  Thanks guys!!!

DRZE is lighter than most 4t enduros. :D

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Had an "E"model with aftermarket slip-on, changed it to the  yoshi with the  really big header and the difference was much,much more bottom and mid-range.

   Was pretty loud too without the spark arrester, but was a good sound echo-ing off the hills!

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10 hours ago, ptgarcia said:

Well the header is the major restriction in the exhaust system on these bikes, so I'd probably recommend the Yosh since it has the larger header. Do you have a stock E header to compare header diameters? From the factory, the E header is slightly larger than the S and SM headers, and most aftermarket exhaust headers are roughly the same size as the factory E. My guess is the T4 is smaller than the factory E header and would stifle performance.

Can you post pictures of the Pro Circuit setup?

Also, whats with that rear bracket on the Yosh muffler?

I will try to get a shot of the other bike with the ProCircuit system.  The bracket on the Yoshi muffler is to lend strength to the other fender, a Baja Kit fender with turn sigs and tail light. I swapped that fender out and put in a very small LED tail system.  This fender has thinner of a side rib and does not reach the bracket.  Working out what I will do with that if I keep the Yoshi system.

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53 minutes ago, sbmon said:

E subframe? How does that rs2 midpipe mount?

 

same as the ProCircuit, except the Yoshi header reaches all the way back to the subframe where the muffler mounts after with two heavy springs to it.  The T4 header just mounts at the cylinder with the muffler section sliding over it next to the carb area.

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Here is a low quality shot of the '01 just after I bought it and brought her back to life, being the stock FCR Pilot circuit was having issues and not run off of choke.

The issue with this Yoshi is that it seems that the bike took a spill and on the right and something hit the header hard enough that it bent the front of it that it pushed the sub frame mount past the sub frame mount bracket. So the sub frame bracket was cut open to be a reversed "C", a slot if you will, and an over sized(3/4") flat allen head bolt just pinches enough of it to hold well. Haven't had any issues with it.  If you zoom in on the photo you can just make it out.  Also note the Baja Kit fender where that mystery bracket on the Yoshi muffler mounts to it.

  I will say that this bike has shit loads of bottom end. but I think it needs a little more mid to top, but it gets up and goes as is. 

FullSizeRender 2.jpg

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That isn't the Yoshimura TRC. There is nothing special about either, pick the one you like best.


Sent from my XT1650 using ThumperTalk mobile app



Not sure what the TRC model you refer to is. This bike was set up with this exhaust back in 2001 so it would be an early Yoshi/Suzuki developed system, correct? The header's OD is about 3cm fatter than the ProCircuit T4 header. Figuring this out makes me think about double checking the jetting in this carb that was swapped over from the '02 ProCircuit set up, although it seems fine, maybe just lift the needle one click.

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The TRC was Yoshimura's top of the line titanium race exhaust, probably the best exhaust ever made for the DRZ. The TRC set the benchmark in performance for the DRZ and is what Dave Harryman and Eddie Sisneros were trying to equal and/or surpass when developing the MRD/SSW (now called Z-Pro) exhaust. It's been out of production for many years now.

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33 minutes ago, ptgarcia said:

The TRC was Yoshimura's top of the line titanium race exhaust, probably the best exhaust ever made for the DRZ. The TRC set the benchmark in performance for the DRZ and is what Dave Harryman and Eddie Sisneros were trying to equal and/or surpass when developing the MRD/SSW (now called Z-Pro) exhaust. It's been out of production for many years now.

Thanks for the great info.  Are you able to ID which Yoshi model mine is?  The system is three sections.  There is no defining marks or label that I can find with any model but the Spark Arrestor insert model. The header and mid pipe pretty sure are Titanium. The header and mid pipe union right at the front of the exhaust heat shield.  How can I ID this set up aside from one of you guys telling me, not that I do not trust, just that I would like the know how as well.

Thanks guys.

 

 

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The exhaust in the pictures you posted above looks like the RS2 to me. I don't recall the TRC having a heat shield and I believe the header and mid-pipe were heald together with springs. The can cross section was triangular, also, not oval.

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It's an rs2 can. I'm pretty sure that can was not developed for many years after 2001. It also looks like the mid pipe mount was bent (could be the pic angle) possibly to fit the E model subframe, this would likely explain why the can mount was also cut to a C shape to fit.

 

 

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It's an rs2 can. I'm pretty sure that can was not developed for many years after 2001. It also looks like the mid pipe mount was bent (could be the pic angle) possibly to fit the E model subframe, this would likely explain why the can mount was also cut to a C shape to fit.
 
 

Thanks guys. I'm assuming you are indicating that an E model subframe is different than S & SM subframe. I guess it would make sense if the set up was for the street legal versions and a person mounted it on an E and had to alter the mount to accommodate the different locations. I thought it was due to the dent in the front of the header that bent the system and forced it back a bit. Here are more photos.
IMG_2813.JPGIMG_2814.JPGIMG_2825.JPGIMG_2823.JPGIMG_2824.JPG

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