Subject	How effective are larger TB's?
Posted by	Evan(CA) on October 02, 2012 at 1:44 PM
	This message has been viewed 704 times.
Message	Sometime in the future I will be doing a plenum pull and finally changing out the old style injectors for the new style ones. While the plenum is off I'm considering adding larger TB's but I'm not sure if it's worth it especially since Z1's are really the only game in town and I'd rather not give them my business. I know of a 3076 turbo car with over 500whp that switched from 58mm to 62mm and the gains were negligible. Less than 5hp gain IIRC. For reference: My car and mods Stock motor/turbos/manifolds/TB's 555cc Nismo Injectors Selin Dual POP w/ JWT POP Chargers Ashspec Massives v3 + 2.5" Inlet/IC Piping SZ 3"DP/TP SZ 2.5" Catback UD Pulley RPS Lightweight Flywheel MWS 1-piece Steel DS This is Evan Wright's car with almost the same mods as me except he had exhaust manifolds and SZ accordion replacement intake pipes but stock oem inlets directly off the turbo. This is Adam's car with essentially the same mods as Evan Wright except for Tomei exhaust cams and some mild port and polishing of the upper intake plenum. I imagine Evan did something similar to his plenum when installing the Z1's TB and just didn't both to list it in his profile. It hard to see since the pulls were started at 2k rpm on my car and 2500 rpm on theirs but it appears my car makes a smidge more tq down low and by 3k rpm we are all at 300tq. After that their cars start to pull away a bit and hold the power longer. Anyways my question is how much of their gains are from the larger TB's and how much are from the manifolds? I know it's doubtful but has anyone done back to back testing just changing the TB's, or manifolds, or inlet piping but I'm trying to see where the gains are coming from. I'm no expert but it seems like the inlet piping is huge for gains down low and the manifolds for gains up higher in the power band. I'm not quite sure where the TB's fit in. It's also be curious to see if Rob'z bored out stock TB's make any difference. Perhaps there is a point of diminishing returns on TB size. Thoughts?
Follow Ups	How effective are larger TB's? - Evan(CA) 13:44:32 10/02/12 This is a great question, and I look forward to the answer - Haasz32 14:45:27 10/02/12 you will get someone telling you that it'll be a bottleneck - fuzzymonkey 15:09:45 10/02/12 Sounds like you've changed your tune :) - Evan(CA) 16:31:59 10/02/12 wow, nice find! for a site i'm NEVER on... - fuzzymonkey 17:14:54 10/02/12 I only remembered it because I was the OP of the thread. - Evan(CA) 17:42:59 10/02/12 Difinately not worth the gains considering the head aches - Evan_Wright (Ca) 15:20:28 10/02/12 I'm thinking manifolds - LJZTT 15:32:08 10/02/12 Having held both OEM and MSP manifolds in my hands - Evan(CA) 15:48:44 10/02/12 It is as easy as you say. I used a die grinder. (n/m) - Evan_Wright (Ca) 16:01:00 10/02/12 Well like I said, my situation is likely different.... - LJZTT 16:52:09 10/02/12 all you need to do is enlarge the plenum intake - vorpalZ 17:20:05 10/02/12 Its soft aluminum. not even that hard to do with a dremel. (n/m) - Antihero 11:29:57 10/03/12 if you have all afternoon... :) (n/m) - vorpalZ 14:38:03 10/03/12 Id be surprised if it took me more than an hour. - Antihero 10:45:37 10/04/12 you mean for stanza or for z1? - Antihero 15:54:13 10/02/12 Die grinder with Al cutting/grinding tip, 10 min/side - vorpalZ 15:58:51 10/02/12 bing - fucking - DOE! .... dremel tool works wonders (n/m) - genic 15:40:51 10/04/12 Did you do Stanza TBs or RobZ/Z1? - BlackholeZ 17:04:58 10/03/12 Check out what Rob'Z did. - TheMarlin (MidTN) 17:22:50 10/02/12 The low end gain is not correct . - ArubaDave 18:09:03 10/02/12 Sure enough. - TheMarlin (MidTN) 21:57:26 10/02/12 Not entirely true - Rob'Z 23:30:31 10/02/12 I see - ArubaDave 08:16:15 10/03/12 Re: How effective are larger TB's? - KA8 04:16:45 10/03/12 An important point to remember when going to larger TBs - BlackholeZ 17:19:13 10/03/12 there is a solution to opening resolution by changing the - Dane (Houston) 23:05:16 10/03/12 very nice...thanks for that (n/m) - aliaZ 06:58:55 10/04/12 Exactly, that's what I meant by throttle pulley. - BlackholeZ 15:15:50 10/04/12 Throttle modulation didn't seem to be much of an issue after - maglito 20:46:16 10/05/12
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