I've been reading many threads in the archive about increased power by adding an exhaust to a stock Evo. Many have said that their boost pressure has increased with a free-flowing pipe.

My experience has been just the opposite. After installing a muffler delete pipe on my car the hp has actually decreased by 17% (223hp vs 185 as measured by my G-Tech).

I've since heard by a reputable source that installing such a pipe on a stock vehicle will actually lower the boost levels. The manufacturer of this particular pipe has told me that I should expect a 5-6hp increase on my stock vehicle. What gives?

Can anyone else shed some light on this issue? Thx, Mike.

 

I realize that I probably need to install a MBC. I've got a TurboXS standard laying around. Can someone post a link to a specific thread where it's described how to hook it up? (I have done a search). Thx, Mike.

p.s. I wish the vendor had been forthright about the results on my stock vehicle. They made no mention that I'd have to install a MBC to regain lost performance.

 

I have a Ultimate Racing 2.5 test pipe for sale no performance LOST or CEL. 50 Bux If you are interested contact me
Jinu.sean@verizon.net

The test pipe you are using will trigger CHECK ENGINE LIGHT very soon, the Ultimate Racing is Guarantee no Check engine and performance lost.

 

He didn't say "cat delete" he said "muffler delete".

I don't see how putting a muffler delete would result in lost power. I would look for another cause of the problem.

Easiest way to check is bolt your stock muffler back on and see if your performance goes back to normal. I doubt that is the case, but if it is talk to Dave Buschur about it and knowing him if you are not completely satisfied you will probably get a refund.

Keith

 

He is talking about a muffler delete pipe, not a cat-delete pipe.

He should try to unhook his battery for 10 minutes and then hook it back up so the ECU has to learn again. This will probably help.

 

hmm maybe he made a mistake ? MUFFLER DELETE PIPE ? AXLEBACK ??

 

http://www.machevo.com/buratrrese.html

 

This kind of pisses me off. Using a rice-box-best-guess accelerometer like a Gtech to claim HP, touting it as some sort of proof/truth, and then flaming Buschur's credibility is LAME. Did you make these runs on the same day and on the exact same stretch of road? Was the car at the exact same operating temperature during the runs? Did the outside temperature change at all? Was your electric cooling fan on? Did you run the OEM unit and the BR muffler delete pipe back to back at a dragstrip and/or on a real dyno with equal warm up times to validate your claim? Did you check every one of these variables (and several others that I'm not thinking about off the top of my head)?

Facts:
*The muffler delete pipe is lighter.
*The OEM muffler will provide more HP and torque at lower rpm due to the flapper and smaller diameter path through the muffler itself.
*The BR muffler delete pipe will make more HP from 5000-7000rpm, where it is less restrictive and breathes better, and where you can actually utilize the power in competition.

Boost loss isn't unilateral from car to car. I hit 19psi and tapered to 16 before and after the delete pipe install. Also, I raced a friend's modded WRX before and after the muffler delete pipe and pulled him harder with the new pipe.

Now with that very economical BR pipe, a Pruven test pipe (this piece for offroad only) and an SAFC, I'd still hit 18psi, then fall to 16 at redline. Added an MBC afterward, and with these mods, my car is utterly transformed into a much faster machine than when I bought it for less than $500 of mods invested. Stock, I could barely pull a modded 350Z Track. With these few affordable hop up parts, I completely reeled the same 350Z in with 4 people in my car starting from a 3 car length deficit!

My point is this: Other manufacturers were making independent dyno proven muffler delete pipes for a lot more money, so Buschur Racing makes their own and you claim they aren't being forthright? I'm thankful they actually responded to the request for something economical that makes dyno proven power!

Every car is different. Some guys have held 19psi to redline stock. Sadly, I was not one of those! Maybe your car lost more boost than mine from pulling the muffler, but that's the way the cards fall sometimes. If you truly lost power (unlike myself), you need to use some type of boost controller to get boost back to the stock level. The OEM muffler and cat are the most restrictive parts of the exhaust, so you'll definitely feel a gain once you get your boost issue ironed out- if you've even lost boost. I didn't see what your readings were in your post.

Please don't complain about something that is so affordable when you could use the search function and see real dyno results that will disprove your Gtech that obviously didn't make a repeatable run in the situation you used it. Put the MBC on and be happy or sell the pipe to someone who will utilize it correctly.

[/rant]

Edited because my sentence structure blows.

 

Exactly I had a very nice improvement with mine

 

I recall reading something from one of the aftermarket sites where they mention their low restriction axleback reduces boost levels slightly and thus requires a boost controller to compensate. If anybody can explain or refute this I'd like to hear it. I don't understand how freer exhaust flow could lower boost.

Will a good quality axleback alone increase power on a stock EVO? Or does it only help if you also combine it with other mods?

 

FYI....I just got my car dynoflashed with the Buschur muffler delete pipe and AEM intake installed on the same day. I can tell you that before the pipe I was boosting 19 then tapering to 16-17...Now even AFTER the reflash I am boosting to maybe 18 for a split sec then holding 16-16.5. I still am producing 25 more HP with lower boost. Here's the link to my discussion https://www.evolutionm.net/forums/sh...threadid=46561

 

I'm happy with my Buschur muffler delete pipe. No other mods to the car.

If the car were down 38 HP with the muffler delete pipe, I'd have felt it -- that's a huge power deficit. The day after installing the Buschur pipe, I did plenty of wide-open throttle driving at Summit Point Raceway, at speeds up to 125+ MPH. I had no problem executing passing maneuvers at 100+ MPH; the car was still pulling hard. If it was down on power at all, which I doubt, I certainly couldn't feel it.

 

Well said. I would question the validity of the test instruments and conditions before I would question the mod itself. Considering the well documented restrictions of the stock muffler/exhaust, it would be safe to surmise that the differences are likely due to the test equipment/conditions than anything else.

 

pruvenperformance stated that their axleback exhaust gained hp but dropped a couple of pounds of boost so you need a boost controller to bring it up(http://www.pruvenperformance.com/evoexhaustpics.htm).it might not the same with muffler delete but it seems like the same issue when your not going for the full cat-back package.

 

I'm not going to get into a pissing contest with you. Besides, why are you pissed off? I'm the one who's car is down 17% in hp!

You must not have much experience using the G-Tech accelerometer. I did no less than 5 runs two days ago and they were all extremely close (1%). Do you really believe using a butt-dyno will yield more accurate measurements?

I'm not flaming them - only asking for assistance from some of the folks here. I've already been told by someone that what I'm experiencing is expected. Given this, I'm somewhat puzzled why Buschar didn't mention it to me in my correspondences leading to the purchase of the pipe.

Had I known that I'd have to install a MBC in order to make stock hp with the pipe I would have passed on the purchase. My vehicle is basically stock and that's the way I want to keep it as to not void my extended warranty.

To asnswer some of your questions: No, not the same stretch of road, however both of them were basically both level and at the same elevation. No, the car was not at exactly the same operating temperature. Yes, the outside temp did change by 15 degrees. No, the electric fan was not on for either test (not that it would have mattered). As my post indicated, I used the G-Tech to gauge performance since has proven to be quite consistent.

Sounds like a very scientific test. Was it run on the same day? Was the temp the same? Etc...

Did you read my post? If they knew that the pipe would cause a loss in boost and result in much lower performance than stock, they should have told me. If they didn't know this, then you draw your own conclusions.

Isn't this what I said in my post?

Maybe you're right - I must have just installed it wrong. Thanks for your insights.