05pearl Posted November 25, 2007 Share Posted November 25, 2007 Boooo Butt dyno feels a definite loss of power. I don't think it's in my mind and I am going to get it back on the dyno later to confirm. I would guess 20-30 HP loss, not 5-10. I do not feel the push back into the seat like before. Car used to run through the rpms in 2nd so fast and I can see the tach straining now to reach redline. Currently 20G + meth, perrin up, cobb turbo back except for stock cans. I love the quiet and would kill to have the power before I put the stock cans on with the current lack of noise. However, I put too much into the car only to lose what feel like a significant amount of power. It could be in my mind, "butt" I don't think so. Link to comment Share on other sites More sharing options...
Deer Killer Posted November 25, 2007 Share Posted November 25, 2007 Considering the results PDX got with the stock turbo were really 0hp at ~254whp, 30hp loss with about 50-80 more whp doesn't seem feasable at all. You could just datalog a WOT run over the same area. Or something like 40-80mph accel in 3rd in seconds. Link to comment Share on other sites More sharing options...
05pearl Posted November 26, 2007 Share Posted November 26, 2007 It's not just me because others who have driven with me before and after also feel that it is not the same. to me. I may be back on the dyno in a week or two anyway. If I do, I will see how the numbers compare. Link to comment Share on other sites More sharing options...
Deer Killer Posted November 26, 2007 Share Posted November 26, 2007 It's not just me because others who have driven with me before and after also feel that it is not the same. to me. I may be back on the dyno in a week or two anyway. If I do, I will see how the numbers compare. Feel = subjective, anyhow maybe the tune. PDX retuned for every combo, which is much different than just changing the part. Link to comment Share on other sites More sharing options...
05pearl Posted November 26, 2007 Share Posted November 26, 2007 Yep, that is why I asked earlier in the thread if a new tune was needed for putting stock cans back on. As soon as I get her on the dyno, we will see how close we come to the earlier tuned numbers. For sure, I will try to re-tune for the stock cans. As I said, I love the quiet. If the numbers look good, the stock cans stay. If not, I better learn to love that boxer rumble that so many others hold in such high regard;) Link to comment Share on other sites More sharing options...
Deer Killer Posted November 26, 2007 Share Posted November 26, 2007 How many seconds does it take exhaust to flow from piston to tailpipe at max flow? Coincidentally I found a rough estimate (good reading anyway): http://myfwc.com/boating/airboat/Section3.pdf It's measured in hundreds of feet per second. So the time is in the milliseconds. How much does it really cool off? Link to comment Share on other sites More sharing options...
Legacy_GT_Pilot Posted November 26, 2007 Share Posted November 26, 2007 I've got a similar set-up to you (20G, meth and TMIC), and last weekend took my mufflers off and replaced them with the stock mufflers. I've noticed no loss in power, just a significant decline in noise (thankfully). I've even logged both set-ups, and have seen no change in the boost I hit, the boost curve, and my MAF volts. I'd be surprised if it cost me 5 or 10hp at peak. I'm definitely staying with the stock mufflers. Dave Boooo Butt dyno feels a definite loss of power. I don't think it's in my mind and I am going to get it back on the dyno later to confirm. I would guess 20-30 HP loss, not 5-10. I do not feel the push back into the seat like before. Car used to run through the rpms in 2nd so fast and I can see the tach straining now to reach redline. Currently 20G + meth, perrin up, cobb turbo back except for stock cans. I love the quiet and would kill to have the power before I put the stock cans on with the current lack of noise. However, I put too much into the car only to lose what feel like a significant amount of power. It could be in my mind, "butt" I don't think so. ________ FRIEND ADVICE FORUM Link to comment Share on other sites More sharing options...
05pearl Posted November 26, 2007 Share Posted November 26, 2007 That is good news. I'm going to keep the stock cans on and try to veryify by dyno as I needed to button up a few loose ends at the shop anyway . I have no logging capabilities and can simply compare my last tune numbers to the dyno w/ stock cans. Hopefully it's all in my mind as the butt dyno is not a very good tool. Link to comment Share on other sites More sharing options...
tommypenguin Posted November 26, 2007 Share Posted November 26, 2007 I'm picking up stock cans tonight before my ice hockey game, hopefully wednesday I will mount them after i pick up some ramps. I will give my opinion on the difference. I've been really hesitant to put on stock cans but after 4 of us stage 2 guys here in colorado got speeding tickets this month and 3/4 of us have an exhaust and got picked off keeping up with traffic. I will have to try the stock cans to see if I go dark on the radar for the police again. http://legacygt.com/forums/images/icons/icon10.gif Link to comment Share on other sites More sharing options...
Deer Killer Posted November 26, 2007 Share Posted November 26, 2007 I've got a similar set-up to you (20G, meth and TMIC), and last weekend took my mufflers off and replaced them with the stock mufflers. I've noticed no loss in power, just a significant decline in noise (thankfully). I've even logged both set-ups, and have seen no change in the boost I hit, the boost curve, and my MAF volts. I'd be surprised if it cost me 5 or 10hp at peak. I'm definitely staying with the stock mufflers. Dave What midpipe/y do you have? Link to comment Share on other sites More sharing options...
Legacy_GT_Pilot Posted November 27, 2007 Share Posted November 27, 2007 I've got the X02 mid and Y-pipes mated to an Invidia catted DP. What midpipe/y do you have? ________ FORD FAIRMONT SPECIFICATIONS Link to comment Share on other sites More sharing options...
caramall2 Posted November 27, 2007 Share Posted November 27, 2007 I started a thread on posting 50-80 mph times (3rd gear pulls). It's actually a great way to cheaply check your "butt dyno" as long as outdoor temps, etc, are similar. There's no shifting gears or "driver induced changes" so it can be moderatly accurate. Logging the time vs someone clicking a stop watch is more accurate, which it sounds you can't do (log). That is good news. I'm going to keep the stock cans on and try to veryify by dyno as I needed to button up a few loose ends at the shop anyway . I have no logging capabilities and can simply compare my last tune numbers to the dyno w/ stock cans. Hopefully it's all in my mind as the butt dyno is not a very good tool. Link to comment Share on other sites More sharing options...
tommypenguin Posted November 27, 2007 Share Posted November 27, 2007 So for you guys with aftermarket mid/y/stock mufflers, how did you mate your stock mufflers to the y pipe without having and exhasut leak since there is a difference in size in piping. The holes for the bolts to go through on my perrin flange are .25" further apart for both holes on the perrin flange than stock. Should I just dremmel the stock holes a .25" further apart on the stock muffler? Then get a stock gasket, drill the holes to match the modfified stock flange and liquid gasket to seal it? I also have two new perrin gaskets that connect between the y and mufflers. Any suggestions on how to do this right would be appreciated. Link to comment Share on other sites More sharing options...
Legacy_GT_Pilot Posted November 27, 2007 Share Posted November 27, 2007 The X02 Y-Pipe lined up fine to the stock mufflers. I did not have any issues with the bolt holes at all. The inside diameter of the pipes are different and I'm sure this creates some turbulence, but I've had no issues with exhaust leaks. So for you guys with aftermarket mid/y/stock mufflers, how did you mate your stock mufflers to the y pipe without having and exhasut leak since there is a difference in size in piping. The holes for the bolts to go through on my perrin flange are .25" further apart for both holes on the perrin flange than stock. Should I just dremmel the stock holes a .25" further apart on the stock muffler? Then get a stock gasket, drill the holes to match the modfified stock flange and liquid gasket to seal it? I also have two new perrin gaskets that connect between the y and mufflers. Any suggestions on how to do this right would be appreciated. ________ Hemp marijuana Link to comment Share on other sites More sharing options...
tommypenguin Posted November 27, 2007 Share Posted November 27, 2007 Do you know, what size piping the Xo2 bottle necks to on the y connection? The perrin pipe is 2.5" connection to the muffler from the y. I was sitting my new perrin gasket on top of the stock muffler flange and there is no way the bolt holes will line up w/o mod for me, unless I'm missing something. Link to comment Share on other sites More sharing options...
Legacy_GT_Pilot Posted November 27, 2007 Share Posted November 27, 2007 If I'm not mistaken, the X02 system is a 3" midpipe splitting into two 2.5" pipes at the Y. The Perrin system you have may be designed to bolt to their mufflers only, whereas the X02 will bolt to thier mufflers as well as the stockers. ________ DC MARIJUANA DISPENSARY Link to comment Share on other sites More sharing options...
nekdut Posted November 27, 2007 Share Posted November 27, 2007 The Perrin system is desgined to bolt to stock as well as their mufflers, since the Perrin mufflers bolt up to the stock Y pipe no problem. Link to comment Share on other sites More sharing options...
BDII Posted November 27, 2007 Share Posted November 27, 2007 people are making lots of power through the stock cans. Like me Need forum help? Private Message legGTLT Link to comment Share on other sites More sharing options...
05pearl Posted November 27, 2007 Share Posted November 27, 2007 So for you guys with aftermarket mid/y/stock mufflers, how did you mate your stock mufflers to the y pipe without having and exhasut leak since there is a difference in size in piping. The holes for the bolts to go through on my perrin flange are .25" further apart for both holes on the perrin flange than stock. Should I just dremmel the stock holes a .25" further apart on the stock muffler? Then get a stock gasket, drill the holes to match the modfified stock flange and liquid gasket to seal it? I also have two new perrin gaskets that connect between the y and mufflers. Any suggestions on how to do this right would be appreciated. Stock mufflers bolted right up to the Cobb Y-pipe with no bolt alignment issues or leaks. I would guess the gaskets took care of any leaks even if there were a difference in pipe sizes. Link to comment Share on other sites More sharing options...
05pearl Posted November 30, 2007 Share Posted November 30, 2007 It's not just me because others who have driven with me before and after also feel that it is not the same. to me. I may be back on the dyno in a week or two anyway. If I do, I will see how the numbers compare. Ok, this ought to be fun. I dyno'd today with the stock cans - No retune, same dyno, different day so obviously different temp, atmos. press.... I have a DB 20G LGT fit running with meth (-20 deg washer fluid) to about 20psi at 5500 ft, EcuTek tune by Ben himself, perrin up, cobb turbo back to mufflers. Everything else the same: With Cobb mufflers: 309whp/340wtq With Stock mufflers: 288whp/294wtq EDIT - see 1/18/08 post for new dyno. Today I tuned in at 307whp/320wtq with stock cans. I guess the low numbers from the Nov dyno was due to the temp, press... of the day. Link to comment Share on other sites More sharing options...
Zed 2.0 Posted November 30, 2007 Share Posted November 30, 2007 Ok, this ought to be fun. I dyno'd today with the stock cans - No retune, same dyno, different day so obviously different temp, atmos. press.... I have a DB 20G LGT fit running with meth (-20 deg washer fluid) to about 20psi at 5500 ft, EcuTek tune by Ben himself, perrin up, cobb turbo back to mufflers. Everything else the same: With Cobb mufflers: 309whp/340wtq With Stock mufflers: 288whp/294wtq Wow, what a difference. Very interesting. Link to comment Share on other sites More sharing options...
tommypenguin Posted November 30, 2007 Share Posted November 30, 2007 Ok, this ought to be fun. I dyno'd today with the stock cans - No retune, same dyno, different day so obviously different temp, atmos. press.... I have a DB 20G LGT fit running with meth (-20 deg washer fluid) to about 20psi at 5500 ft, EcuTek tune by Ben himself, perrin up, cobb turbo back to mufflers. Everything else the same: With Cobb mufflers: 309whp/340wtq With Stock mufflers: 288whp/294wtq Are you f***ing kidding me! damn! that is a huge power loss brotha! I just picked up stock cans too, damn it! There is no way I'm going to want to put them on now. I could sacrifice 10hp, but not gains like that. Or perhaps a retune is needed when you swap out the mufflers? By the way where you live, I have to take a ride in your rocket. I'm getting ready to put my vf40-18g w/ upgraded actuator and I realize from this stock mufflers will hurt performance big time. Thanks for sharing your reseach doctor. Link to comment Share on other sites More sharing options...
05pearl Posted November 30, 2007 Share Posted November 30, 2007 Are you f***ing kidding me! damn! that is a huge power loss brotha! I just picked up stock cans too, damn it! There is no way I'm going to want to put them on now. I could sacrifice 10hp, but not gains like that. Or perhaps a retune is needed when you swap out the mufflers? By the way where you live, I have to take a ride in your rocket. I'm getting ready to put my vf40-18g w/ upgraded actuator and I realize from this stock mufflers will hurt performance big time. Thanks for sharing your reseach doctor. The tuner was surprised too and said that day to day temp fluctuations could have also contributed to the lower numbers. But, I swear I could feel a power loss right after driving with the stock cans. I don't think I could feel only a 5-10 HP loss. It is interesting to say the least. Good news is that I can pop the cobbs back on whenever I want. You may still try your stockers as others claim not to notice much of a difference. I'm in Ft. Collins. If you ever head north, let me know. Link to comment Share on other sites More sharing options...
VTGT Posted November 30, 2007 Share Posted November 30, 2007 I am pretty sure a lot of the difference is accounted for in the day to day fluctuations like you said. To get to the bottom of this you need to dyno all of the setups on the same day . Stock CBE, Stock Mid and Y with Cobb mufflers, Cobb mid and Y into stock muffers, and finally Cobb CBE. That will give us great results to the T, hehe I bet the difference between the Cobb Mid and Y matched to the stock mufflers would be within 10 whp and 15 wtq of the Cobb CBE. Albeit that may be worth it to some, but I prefer to fly under the radar From observing other threads modding the stock mufflers with an aftermarket mid and y would probably close the gap even more Link to comment Share on other sites More sharing options...
Deer Killer Posted November 30, 2007 Share Posted November 30, 2007 If I can get 50% of that back through tuning, I'll be OK. That's really unclear without actually doing it. Link to comment Share on other sites More sharing options...
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