Advice on TB -> 52 vs. 58 Please
Thread Starter
Drifting
Joined: Feb 2003
Posts: 1,292
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From: Beavercreek OR
Advice on TB -> 52 vs. 58 Please
Ok 383, SR, 74219, 30lb SVO, AFR 195's,Holley AFPR, 9.8:1 comp, CompCams Promag 1.6, Hooker 2151's, true duals, R/T metal matrix bullets, x-pipe, Borla stainless catback [edit] rebuilt upgraded 700R4, 2500 stall lock up, D44 3.33 gears. Walbro fuel pump, camber brace, and harness bar not yet installed.
I currently have a 58 mm malfunctioning, rebuild for $190 or replace, hopefully from a member with a 52 or 58mm is the question. I'd like to know first, if I should really be in a 52, and secondly if the 58 is OK is it worth rebuilding. It's got an SLP plate. Thanks in advance for your assistance :yesnod:
[Modified by 86Moon, 6:35 PM 2/9/2004]
[Modified by 86Moon, 2:09 PM 2/12/2004]
[Modified by 86Moon, 11:51 PM 2/12/2004]
I currently have a 58 mm malfunctioning, rebuild for $190 or replace, hopefully from a member with a 52 or 58mm is the question. I'd like to know first, if I should really be in a 52, and secondly if the 58 is OK is it worth rebuilding. It's got an SLP plate. Thanks in advance for your assistance :yesnod:
[Modified by 86Moon, 6:35 PM 2/9/2004]
[Modified by 86Moon, 2:09 PM 2/12/2004]
[Modified by 86Moon, 11:51 PM 2/12/2004]
Team Owner
Joined: Dec 2000
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From: SE NY
Cruise-In II Veteran
Re: Advice on TB -> 52 vs. 58 Please (86Moon)
I'm currently running a 52mm TB with my stock heads, cam and headers and only a 350cib engine and it works very well.
I think you would do well with a 58mm TB.
Since you are getting a used TB try to get a AS&M unit. I've seen them at the plant and they are very high quality, whereas the BBKs don't even come close in quality.
I think you would do well with a 58mm TB.
Since you are getting a used TB try to get a AS&M unit. I've seen them at the plant and they are very high quality, whereas the BBKs don't even come close in quality.
Pro
Joined: Dec 1999
Posts: 559
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From: Coppell TX
Re: Advice on TB -> 52 vs. 58 Please (86Moon)
might as well stick with the 58mm. You cant really go "too big". About the only thing you will hurt is tipin, but on your setup I think its moving enough air.
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: Advice on TB -> 52 vs. 58 Please (86Moon)
I dont see why you would need a 58, but with a 383 it wouldnt hurt.
The MAF only flows 700cfm or so with all the fins and screens removed, and the 52mm flows 750.
The MAF only flows 700cfm or so with all the fins and screens removed, and the 52mm flows 750.
Team Owner
Joined: Sep 2001
Posts: 62,160
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: Advice on TB -> 52 vs. 58 Please (JordonMusser)
remember that "700cfm" is at a pressure drop across the test subject. anytime you can minimize losses, it is an advantage.
Pro
Joined: Dec 1999
Posts: 559
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From: Coppell TX
Re: Advice on TB -> 52 vs. 58 Please (Corvette0096)
Right, but the test pressures you are refering to are probably not the same.
Will he pick up with the 58 over a 52? if any.. it will be little.. but it certainly wouldnt hurt.
fyi, i ran a 58mm on my 383, it ran 11.2s @ 124mph in a 3700lb car. (6spd)
I later stepped up to a monoblade for my 401ci motor, but it probably wasn't needed, but I was trying to eliminate any potential restrictions. The 401 was MUCH faster than my 383, but most of it was cylinder heads.
Will he pick up with the 58 over a 52? if any.. it will be little.. but it certainly wouldnt hurt.
fyi, i ran a 58mm on my 383, it ran 11.2s @ 124mph in a 3700lb car. (6spd)
I later stepped up to a monoblade for my 401ci motor, but it probably wasn't needed, but I was trying to eliminate any potential restrictions. The 401 was MUCH faster than my 383, but most of it was cylinder heads.
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Re: Advice on TB -> 52 vs. 58 Please (JordonMusser)
remember that "700cfm" is at a pressure drop across the test subject. anytime you can minimize losses, it is an advantage.
Opening up the airlfow at the intake system and TB always helps when trying to change the pressure or volume of air,but for many engines,it doesnt do much except lighten your wallet.Im sure a 383 can maybe benefit from a 52MM TB but using a 58MM with 1000CFm of flow,how can the engine inhale that if it isnt forced fed?Even if your trying to change pressure up front?
Im not saying it doesnt work,but I dont see how it can possibly net the $$ to gain ratio any good over the smaller sizes.
Just wondering what the others thoughts on the subject would be.
:)
Thread Starter
Drifting
Joined: Feb 2003
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From: Beavercreek OR
Re: Advice on TB -> 52 vs. 58 Please (Bill's86Coupe)
Interesting discussion and I'm paying attention believe me. I'm sure this has been discussed before.
I forgot to mention that I have the P&P runners and Tpis Bigmouth intake with the SR, not that it makes a difference. I understand that the chokepoint is the MAF apparently at this point.
I'm not particularly concerned since I already have a 58 that I can have rebuilt. The general consesus seems to be that it's probably overkill but it wouldn't be detrimental to the prformance the way going to a 58 from a 48 in a stock setup is.
It would seem that the only decision I really need to make here is weather to drop the $190 on the rebuild or if someone shows up with a great deal on something that is better than what I've got, such as the AS&M suggested by 65ZO1. I'm gonna try to put the stock TB on over the next couple days and see what if anything turns up. Otherwise I'll probably send this one out for some boring and sealed bearings.
But I'd be interested to see the conversation continue if there is interest. Thanks to all :cheers:
I forgot to mention that I have the P&P runners and Tpis Bigmouth intake with the SR, not that it makes a difference. I understand that the chokepoint is the MAF apparently at this point.
I'm not particularly concerned since I already have a 58 that I can have rebuilt. The general consesus seems to be that it's probably overkill but it wouldn't be detrimental to the prformance the way going to a 58 from a 48 in a stock setup is.
It would seem that the only decision I really need to make here is weather to drop the $190 on the rebuild or if someone shows up with a great deal on something that is better than what I've got, such as the AS&M suggested by 65ZO1. I'm gonna try to put the stock TB on over the next couple days and see what if anything turns up. Otherwise I'll probably send this one out for some boring and sealed bearings.
But I'd be interested to see the conversation continue if there is interest. Thanks to all :cheers:
Drifting
Joined: Aug 2000
Posts: 1,614
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From: Colleyville Texas
Re: Advice on TB -> 52 vs. 58 Please (86Moon)
Running good with with 52MM TB on my 396 LT1. 28LBS LT4 injectors. Took a year to get the car tuned right so not ready to change anything at this point. 58MM might squeeze out a few more HP though.
Thread Starter
Drifting
Joined: Feb 2003
Posts: 1,292
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From: Beavercreek OR
Re: Advice on TB -> 52 vs. 58 Please (Red Rocket)
YaBut, What about this :confused:
http://forums.corvetteforum.com/zerothread?id=749939
I wish BluByYou would have posted here as well. Quite interesting :crazy:
[Modified by 86Moon, 7:35 PM 2/10/2004]
http://forums.corvetteforum.com/zerothread?id=749939
I wish BluByYou would have posted here as well. Quite interesting :crazy:
[Modified by 86Moon, 7:35 PM 2/10/2004]
Racer
Joined: Sep 2002
Posts: 270
Likes: 1
From: Portland OR
Re: Advice on TB -> 52 vs. 58 Please (86Moon)
Forgive my ignorance, but what is "tip in"? I read in a car magazine once that when they were rebuilding an engine, they with 58 over a 52 because "it can't hurt, and they cost the same."
Thread Starter
Drifting
Joined: Feb 2003
Posts: 1,292
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From: Beavercreek OR
Re: Advice on TB -> 52 vs. 58 Please (JADVette94)
Not sure what you're "tip in" is reffering to maybe a typo?. But e-mail me let's talk on the phone. Always good to meet another brother :yesnod:
Pro
Joined: Dec 1999
Posts: 559
Likes: 17
From: Coppell TX
Re: Advice on TB -> 52 vs. 58 Please (86Moon)
Tipin in the most basic terms is how responsive the throttle is right off idle. with a really large TB, you can flow a lot of air even at 5% throttle (for example) so the motor tends to be jumpy right off idle.
If, if the motor flows 600cfm max, and your TB can flow 600cfm @ 15% blade opening...
get the idea?
If, if the motor flows 600cfm max, and your TB can flow 600cfm @ 15% blade opening...
get the idea?
Le Mans Master
Joined: Feb 2000
Posts: 9,715
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From: Kempner Texas
Re: Advice on TB -> 52 vs. 58 Please (JordonMusser)
Tipin in the most basic terms is how responsive the throttle is right off idle. with a really large TB, you can flow a lot of air even at 5% throttle (for example) so the motor tends to be jumpy right off idle.
If, if the motor flows 600cfm max, and your TB can flow 600cfm @ 15% blade opening...
get the idea?
If, if the motor flows 600cfm max, and your TB can flow 600cfm @ 15% blade opening...
get the idea?
Based on the prices I've seen, the 58 is more expensive too.
One of the mags, I believe it was Corvette Fever, just ran an article on the power differences among different size carbs. I know this is wet flow Vs dry flow, so it's not apples to apples, but was interesting reading. Also, the results were computer simulation data, not dyno results.
As the carb size was increased power continued to climb.
Jake
Race Director
Joined: Nov 2000
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From: stop the fun suckers
Re: Advice on TB -> 52 vs. 58 Please (86Moon)
YaBut, What about this :confused:
http://forums.corvetteforum.com/zerothread?id=749939
I wish BluByYou would have posted here as well. Quite interesting :crazy:
[Modified by 86Moon, 7:35 PM 2/10/2004]
http://forums.corvetteforum.com/zerothread?id=749939
I wish BluByYou would have posted here as well. Quite interesting :crazy:
[Modified by 86Moon, 7:35 PM 2/10/2004]
Thread Starter
Drifting
Joined: Feb 2003
Posts: 1,292
Likes: 0
From: Beavercreek OR
Re: Advice on TB -> 52 vs. 58 Please (BluByU)
BluByU thanks for coming in! Sorry I trashed your name above :yesnod: but at my age the memory is a little suspect :jester I read all the info you provided in the other posts and as a result was not expecting what I experienced today.
I changed out my 58 for the stock 48 and my ayss told a different story. Now my MAF screen is gone, but I haven't even hogged out the heat sinks yet. I noticed a HUGE difference in the response of the motor (how quickly it revved) both in neutral and under power. I know that this is subjective info but there is no doubt in my mind. On the neurtal part the mechanic in the shop where I changed it out noticed and commented immediately.
The LPE is getting a rebuild :yesnod: If I can stand the wait I'm gonna get dyno #'s for both when TJ does my final tune. I'll start with the 48 and then put the 58 on if I can talk him into it. It'll only take about 30 min. to change it out.
I changed out my 58 for the stock 48 and my ayss told a different story. Now my MAF screen is gone, but I haven't even hogged out the heat sinks yet. I noticed a HUGE difference in the response of the motor (how quickly it revved) both in neutral and under power. I know that this is subjective info but there is no doubt in my mind. On the neurtal part the mechanic in the shop where I changed it out noticed and commented immediately.
The LPE is getting a rebuild :yesnod: If I can stand the wait I'm gonna get dyno #'s for both when TJ does my final tune. I'll start with the 48 and then put the 58 on if I can talk him into it. It'll only take about 30 min. to change it out.
Thread Starter
Drifting
Joined: Feb 2003
Posts: 1,292
Likes: 0
From: Beavercreek OR
Re: Advice on TB -> 52 vs. 58 Please (JordonMusser)
I saw that :eek: It would seem to me that that will get you a better 60' thusly a better 1/4 mi if you can hook, and I will :cheers:
[Modified by 86Moon, 7:52 PM 2/11/2004]
[Modified by 86Moon, 7:52 PM 2/11/2004]