# 3" Exhaust adds 3lb of boost... **URL:** \ **Category:** PittSpeed Automotive\ **Created:** [April 26, 2006, 7:18pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899 "2006-04-26T19:18:43Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![ZEX350Z](https://avatars.discourse-cdn.com/v4/letter/z/87869e/32.png) [@ZEX350Z](https://forums.speedlife.net/u/ZEX350Z)\ **Post date:** [April 26, 2006, 7:18pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/1 "2006-04-26T19:18:43Z")
OK, this is retarded but…I got a full 3" exhaust put on my turbo accord today. The stock exhaust was on there w/ a cat. I went to leave 1st Try and went to feel the car and HOLY SHIT. I go through the gears a few times and it keeps suprising me how fucking fast it was just w/ adding a exhaust. So I’m on 279 and decide to open it up at 70mph, I look up at the boost gauge and its reading 8psi…immediatly I let off the gas. I hti 8 psi like 2 more times on my way home and it was great but can’t be good for the car since it was tuned at 5psi w/ AEM EMS. The vac lines are fine so here goes my questions… 1.)The car is using the garrett internal wastegate. When hybrid tuned it it was at 5 psi on stock exhaust. Do these things go bad?(seems to coincidental) 2.) I never heard of a 5psi wastegat on a garrett T3, so could a clogged up catalytic converter been holding back boost? 3.)How unsafe is it to drive the car like this? 😉 Any other feedback will be greatly appreciated…there are no vacuum line issues at all. It has to be something w/ the exhaust I am thinking, although it is hard to beleive. The stock exhaust was like 1.75" or something. The car runs super rich so I wouldn’t be suprised if the catalytic convertor was clogged…HELP Please ! ---
**Author:** ![ZEX350Z](https://avatars.discourse-cdn.com/v4/letter/z/87869e/32.png) [@ZEX350Z](https://forums.speedlife.net/u/ZEX350Z)\ **Post date:** [April 26, 2006, 7:21pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/2 "2006-04-26T19:21:26Z")
also there is no boost controller on the car yet, and I remeber hybid dynamics being somewhat suprised that the internal wastegate was only 5 psi. We didn’t even pop the hood once while I was ther getting the exhaust on, so NOTHING was touched under there. ---
**Author:** ![neonmike22](https://avatars.discourse-cdn.com/v4/letter/n/ba8739/32.png) [@neonmike22](https://forums.speedlife.net/u/neonmike22)\ **Post date:** [April 26, 2006, 7:34pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/3 "2006-04-26T19:34:09Z")
With less flow resriction from the big exhaust, the turbine can flow as much as it can, vs before where it was limited by how much the small exhaust could flow. You’re seeing more boost with the same wastegate setting becuase it can flow more. ---
**Author:** ![ZEX350Z](https://avatars.discourse-cdn.com/v4/letter/z/87869e/32.png) [@ZEX350Z](https://forums.speedlife.net/u/ZEX350Z)\ **Post date:** [April 26, 2006, 7:42pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/4 "2006-04-26T19:42:20Z")
so will the stock FPR boost fuel pressure w/ the increase in boost? Does the car need to be re-tuned? ---
**Author:** ![T70\_Tsi](https://avatars.discourse-cdn.com/v4/letter/t/898d66/32.png) [@T70\_Tsi](https://forums.speedlife.net/u/T70_Tsi)\ **Post date:** [April 26, 2006, 7:45pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/5 "2006-04-26T19:45:13Z")
well, when you tune for the amount of fuel per particle of air theoretically should require very little changes as boost inscreases within the limits of detonation. at 5psi i’m still scratching my head why you bothered spending tons of money on ems ---
**Author:** ![ZEX350Z](https://avatars.discourse-cdn.com/v4/letter/z/87869e/32.png) [@ZEX350Z](https://forums.speedlife.net/u/ZEX350Z)\ **Post date:** [April 26, 2006, 7:48pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/6 "2006-04-26T19:48:24Z")
I could only go to 5PSI temporarily b/c of a small intercooler…thats fixed now. The 3" exhaust went on so I could take it to get tuned next week for 9 psi, butI might throw the wideband in tmrw and leave it as is. ---
**Author:** ![T70\_Tsi](https://avatars.discourse-cdn.com/v4/letter/t/898d66/32.png) [@T70\_Tsi](https://forums.speedlife.net/u/T70_Tsi)\ **Post date:** [April 26, 2006, 7:49pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/7 "2006-04-26T19:49:17Z")
i still dont’ get it, i guess you can’t go fast without ems ---
**Author:** ![flyinglow57](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/flyinglow57/32/5978_2.png) [@flyinglow57](https://forums.speedlife.net/u/flyinglow57)\ **Post date:** [April 26, 2006, 7:50pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/8 "2006-04-26T19:50:29Z")
my srt would pick up 2-3 lbs when i would uncap the cutout. so its normal. now the main problem is can the motor take 8 lbs of boost? ask hybrid they can tell you more info on your car and tune. glad to see it is runnin way better ---
**Author:** ![bgblockelcamino](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/bgblockelcamino/32/5997_2.png) [@bgblockelcamino](https://forums.speedlife.net/u/bgblockelcamino)\ **Post date:** [April 26, 2006, 7:51pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/9 "2006-04-26T19:51:52Z")
awesome, pretty happy with the way it turned out too. ---
**Author:** ![ZEX350Z](https://avatars.discourse-cdn.com/v4/letter/z/87869e/32.png) [@ZEX350Z](https://forums.speedlife.net/u/ZEX350Z)\ **Post date:** [April 26, 2006, 7:52pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/10 "2006-04-26T19:52:41Z")
can the motor take it? who cares…the exhaust costs more than the motor on shifts…Its getting a compression test tmrw ---
**Author:** ![ZEX350Z](https://avatars.discourse-cdn.com/v4/letter/z/87869e/32.png) [@ZEX350Z](https://forums.speedlife.net/u/ZEX350Z)\ **Post date:** [April 26, 2006, 8:00pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/11 "2006-04-26T20:00:54Z")
T70…whats a good AFR at WOT? I’ll hook up the wideband and see where i’m at, and see if the knock sensor is getting any voltage ---
**Author:** ![T70\_Tsi](https://avatars.discourse-cdn.com/v4/letter/t/898d66/32.png) [@T70\_Tsi](https://forums.speedlife.net/u/T70_Tsi)\ **Post date:** [April 26, 2006, 8:29pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/12 "2006-04-26T20:29:55Z")
11.5 ---
**Author:** ![1320](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/1320/32/5949_2.png) [@1320](https://forums.speedlife.net/u/1320)\ **Post date:** [April 26, 2006, 8:50pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/13 "2006-04-26T20:50:41Z")
> [@T70\_Tsi](#): > > i still dont’ get it, i guess you can’t go fast without ems I think he bought it because he found a killer deal on one used. ---
**Author:** ![ZEX350Z](https://avatars.discourse-cdn.com/v4/letter/z/87869e/32.png) [@ZEX350Z](https://forums.speedlife.net/u/ZEX350Z)\ **Post date:** [April 26, 2006, 8:59pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/14 "2006-04-26T20:59:31Z")
650 used…about the going rate…got a AFC first, but sold that crap the day after i installed it ---
**Author:** ![Pewter](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/pewter/32/5936_2.png) [@Pewter](https://forums.speedlife.net/u/Pewter)\ **Post date:** [April 27, 2006, 4:32am UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/15 "2006-04-27T04:32:06Z")
nice good luck ---
**Author:** ![BlkP42E](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/blkp42e/32/5938_2.png) [@BlkP42E](https://forums.speedlife.net/u/BlkP42E)\ **Post date:** [April 27, 2006, 5:40am UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/16 "2006-04-27T05:40:40Z")
> [@ZEXaccord](#): > > 650 used…about the going rate…got a AFC first, but sold that crap the day after i installed it find me one for 650 then ---
**Author:** ![ZEX350Z](https://avatars.discourse-cdn.com/v4/letter/z/87869e/32.png) [@ZEX350Z](https://forums.speedlife.net/u/ZEX350Z)\ **Post date:** [April 27, 2006, 6:35am UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/17 "2006-04-27T06:35:16Z")
> [@BlkP42E](#): > > find me one for 650 then I tried. There are not nearly as many used ones for the stangs as there are for the hondas. I actually lucked out and seen an ebay auction that was listed in coraopolis(sp). The guy had a 98 accord w/ 440 WHP. He wants to sell me his built motor(car is going back to stock) for 1,500 built by Passin(again sp.) Motorsports in Ohio. He said it could have gone higher but the ignition broke up. I may need it soon. It is the next best thing I ever bought for the car next to the exhaust by Jeff at 1st Try. Just drove it again this morning to my final and it screamed. The tone is great, mellow deep and crisp. I am going to datalog today and make sure there isn’t a knock or lean mixture at WOT. I have probably almost doubled the HP of this car now on stock internals. A compression test is being done today to make sure everything is straight. ❌ ---
**Author:** ![ZEX350Z](https://avatars.discourse-cdn.com/v4/letter/z/87869e/32.png) [@ZEX350Z](https://forums.speedlife.net/u/ZEX350Z)\ **Post date:** [April 27, 2006, 5:27pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/18 "2006-04-27T17:27:40Z")
did a compression test today…200 PSI across all 4. Plugs looked good, and replaced them. I’m a happy guy right now. ---
**Author:** ![fmfkid250](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fmfkid250/32/5973_2.png) [@fmfkid250](https://forums.speedlife.net/u/fmfkid250)\ **Post date:** [April 27, 2006, 6:13pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/19 "2006-04-27T18:13:47Z")
that motor should be good for 9psi easy esp on that turbo ---
**Author:** ![SmokinDiesel](https://avatars.discourse-cdn.com/v4/letter/s/57b2e6/32.png) [@SmokinDiesel](https://forums.speedlife.net/u/SmokinDiesel)\ **Post date:** [April 27, 2006, 6:44pm UTC](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899/20 "2006-04-27T18:44:31Z")
> [@pewterss](#): > > nice good luck [Next page](https://forums.speedlife.net/t/3-exhaust-adds-3lb-of-boost/181899.md?page=2)