Subject	according to effective compression analysis
Posted by	gt300zxtt on November 29, 2007 at 11:26 PM
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In Reply To	Would the acceleration of a TT be the same as an NA posted by robo (sebring1970) on November 29, 2007 at 07:40 AM
Message	a TT engine with 8.5 static compression ratio would need between 3 to 4 psi of boost in order to have an equivalent effective compression of a n/a engine with 10.5 static compression ratio. in order to test this theory/analysis, one could log a torque and horsepower vs vacuum/boost pressure.
Follow Ups	Would the acceleration of a TT be the same as an NA - robo (sebring1970) 07:40:36 11/29/07 TT motors are lower compression - BlackholeZ 07:42:41 11/29/07 That, and the differential wouldn't allow it to accelerate - viper498 08:18:16 11/29/07 He said all else being the same "gearing..." (n/m) - PennStateZ 09:52:19 11/29/07 thank you. my original question sort of sucked. - robo (sebring1970) 09:59:33 11/29/07 Indeed he did. Sorry about that. (n/m) - viper498 11:22:25 11/29/07 I would expect the TT to make more power than the NA - ZEngineer 08:18:20 11/29/07 But don't you have to boost before that makes a difference? (n/m) - viper498 08:20:16 11/29/07 nope, I'm talking about the energy spent to negate vacuum - ZEngineer 08:24:08 11/29/07 But if you lost compression in all of the cylinders in an NA - viper498 08:26:53 11/29/07 what spools the turbos? (n/m) - Guapo 08:50:34 11/29/07 midgets in low RPM, then leprechauns take over above 3k (n/m) - ZEngineer 08:59:36 11/29/07 little rat-basta.... (n/m) - RSR 09:11:57 11/29/07 =) (n/m) - ZEngineer 10:50:25 11/29/07 Leprechauns take over at ~2750 with downpipes :) (n/m) - Slow3z 09:15:00 11/29/07 Residual heat mostly that would otherwise be wasted. (n/m) - ZCulture 10:26:29 11/29/07 but yes, there would be very little of that - ZCulture 10:29:11 11/29/07 residual heat spools the turbos? I thought it was exhaust - Guapo 10:41:13 11/29/07 Yes, it's the exhaust flow but it's the heat energy - ZCulture 11:22:24 11/29/07 Your logic is good... - PennStateZ 11:59:10 11/29/07 fair enough :) (n/m) - Guapo 12:00:33 11/29/07 I would tend to agree as my guess would be that - Audioquest 08:52:19 11/29/07 Negative VE? - Chris-TTZ 09:31:47 11/29/07 Isn't any non-forced induction always less than 100% - Audioquest 09:58:23 11/29/07 less than 100% VE is not negative VE. - Chris-TTZ 11:48:22 11/29/07 Not really =). - Kenny 11:05:02 11/29/07 you suck air, and you're trivial. (n/m) - ZEngineer 11:20:04 11/29/07 No, even at neutral pressure, the Twin Turbo sticker - brahmabull (CT) 08:25:06 11/29/07 LOL! - viper498 08:28:26 11/29/07 Doah! I'm down to 250. I replaced my wing I have no sticker! (n/m) - Audioquest 10:23:50 11/29/07 My thoughts... - Barry'z (NJ) 09:27:37 11/29/07 False. It would actually go to 0. - MixManMash 09:35:33 11/29/07 Isn't the NA (or any non-forced induction engine) - Audioquest 10:31:34 11/29/07 No. At wide open throttle the manifold pressure will show up - MixManMash 11:40:02 11/29/07 I find it hard to believe that our intake tract - Barry'z (NJ) 13:32:39 11/29/07 not quite zero, but pretty close. (n/m) - BlackholeZ 14:13:43 11/29/07 you've got it backwards - ZEngineer 09:37:50 11/29/07 now you're confusing me - robo (sebring1970) 09:41:16 11/29/07 It rotates whenever the engine is running. - MixManMash 09:50:07 11/29/07 to my way of thinking, a TT should run about the same - robo (sebring1970) 09:32:21 11/29/07 that's because it's wasting energy spooling up the turbines - ZEngineer 09:39:52 11/29/07 really? spooling the turbos is that much of a parasitic - robo (sebring1970) 09:42:40 11/29/07 I would think so - ZEngineer 09:54:54 11/29/07 but it's all passive, that's why forced induction with a - robo (sebring1970) 10:02:29 11/29/07 Do you mean more power than without turbos? - TriniTT 10:45:05 11/29/07 That's because you can't WOT it without going into boost - TriniTT 09:47:52 11/29/07 that makes sense, and it's so obvious. no wonder I - robo (sebring1970) 09:49:57 11/29/07 do you not understand compression ratios? (n/m) - Spee 00:04:35 11/30/07 sure I do. my original question was not phrased very well. - robo (sebring1970) 09:33:03 11/30/07 Drugs are bad. (n/m) - Bernie (NoVA) 09:43:08 11/29/07 For better or worse, this is my state of mind au naturale (n/m) - robo (sebring1970) 09:48:47 11/29/07 TT w. blown turbos is slower then a NA. (n/m) - Bernie (NoVA) 09:55:37 11/29/07 All else being equal, the NA would be faster. - PennStateZ 09:55:45 11/29/07 Fact: TT engine outputs more power after 2500RPM - ZCulture 10:25:23 11/29/07 I assure you it isn't. (n/m) - Kenny 11:12:49 11/29/07 Overlay TT and NA dyno charts and see for yourself. (n/m) - ZCulture 11:28:22 11/29/07 Alright man, here ya go. - ZCulture 11:40:29 11/29/07 Re: How do you do the comparison? - IB 12:30:42 11/29/07 That's how the simulator shows them. - ZCulture 14:05:36 11/29/07 Re: That's how the simulator shows them. - IB 18:15:54 11/29/07 If you mean with spooling turbos, you're correct - TriniTT 11:34:45 11/29/07 Yes, I wasn't really answering the question. - ZCulture 11:38:16 11/29/07 "I wasn't really answering the question." - PennStateZ 12:07:34 11/29/07 yes, but with stock turbos you're already in boost (n/m) - Guapo 11:50:10 11/29/07 stop posting (n/m) - Spee 23:59:34 11/29/07 can you force the wastegates open - apudapus 11:09:17 11/29/07 NA would be faster - NytWolf 11:33:17 11/29/07 no offense, but this may be the most retarded thread - fantomZ(OH) 11:57:42 11/29/07 bench racing on the internet rawks - fourZero 12:20:02 11/29/07 Someone answered this question a few years ago. - SpdDemon13 (Japan) 12:53:07 11/29/07 according to effective compression analysis - gt300zxtt 23:26:54 11/29/07
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