52mm or 58mm
Thread Starter
Registered User
Joined: May 2002
Posts: 4,579
From: Cincinnati, OH
52mm or 58mm
I'm thinking 52mm with what I have. But taking in consideration to the 58mm, since its not that much more. But no forced induction, so I'm not sure. Here's my mods:
Elliott Heads
306 cam
Longtubes
off-road y
SLP Loudmouth
SLP/GMPP CAI
1.6rr's
Which TBs do you guys recommend?
Elliott Heads
306 cam
Longtubes
off-road y
SLP Loudmouth
SLP/GMPP CAI
1.6rr's
Which TBs do you guys recommend?
Registered User
Joined: Jul 2001
Posts: 752
From: Double Oak TX
Tell ya what I recommend.
Get your intake ported for a 58mm TB so either the 58 or 52mm TB will work. Go to a shop whom has both TB's and a dyno. Dyno the car with both and see which one works the best.
You would be doing everyone a favor as this string has gone on forever with no one actually dynoing the difference. Instead someone pull out a bunch of mathmatical formula's and tells ya which one should work the best.
If ya want to wait a couple of months or so, I doing the exact same thing myself so there are some more objective answers regarding TB efficiency.
I'm redoing my 383 and have a 52 mm TB. I going to borrow an 58 mm TB and see after LT1.edit tuning which works the best.
Maybe then someone will have a real answer.
Get your intake ported for a 58mm TB so either the 58 or 52mm TB will work. Go to a shop whom has both TB's and a dyno. Dyno the car with both and see which one works the best.
You would be doing everyone a favor as this string has gone on forever with no one actually dynoing the difference. Instead someone pull out a bunch of mathmatical formula's and tells ya which one should work the best.
If ya want to wait a couple of months or so, I doing the exact same thing myself so there are some more objective answers regarding TB efficiency.
I'm redoing my 383 and have a 52 mm TB. I going to borrow an 58 mm TB and see after LT1.edit tuning which works the best.
Maybe then someone will have a real answer.
Registered User
Joined: Jul 2001
Posts: 752
From: Double Oak TX
This is my exact point!
No one has any objective information as to which one works the best for mid to higher mid level performance. It's all.... "according to the cfm you need X".
Don't mean to be a doubting Thomas....... but until someone knows for sure...... they don't know for sure. And..... the only way your going to know for sure is to test the actual results and post it to everyone.
No one has any objective information as to which one works the best for mid to higher mid level performance. It's all.... "according to the cfm you need X".
Don't mean to be a doubting Thomas....... but until someone knows for sure...... they don't know for sure. And..... the only way your going to know for sure is to test the actual results and post it to everyone.
Registered User
Joined: Nov 2003
Posts: 195
From: Walla Walla, WA
Denny kind of hit the nail on the head. Getting an accurate "will this help" is tough to do. I'm going with a 52mm, but I have stock heads and will be installing a baby cam (Frank95z has inspired me). Obviously this is a lot different from your setup. I think the dyno test is a super idea. But the results will really only be applicable to your configuration.
With several users performing the same kind of test (HP/TQ with 52mm vs. 58mm TB) some meaningful trends might be identified. For example, big cam and high flowing heads might see big gains from a bigger TB. While stock heads with baby cam might see very little difference. One concern I have heard with bigger TB (58mm or even monoblade) is the loss of air flow velocity if your not pulling/forcing in enough air. Again, speculation but seems reasonable to me.
I generally agree with some folks on this board that without FI, big cubes, ported heads (generally a high flow setup) the bigger TB may not help much at all. I am mostly using the 52mm because that's the bigged TB my stock intake will really support and it was a really good deal.
EDIT: FYI 52mm have demonstrated the ability to support 331 rwhp (~400 fwhp on an A4). The TB is probably not the restriction in this setup as it uses stock heads, N/A and a 210/224 cam.
With several users performing the same kind of test (HP/TQ with 52mm vs. 58mm TB) some meaningful trends might be identified. For example, big cam and high flowing heads might see big gains from a bigger TB. While stock heads with baby cam might see very little difference. One concern I have heard with bigger TB (58mm or even monoblade) is the loss of air flow velocity if your not pulling/forcing in enough air. Again, speculation but seems reasonable to me.
I generally agree with some folks on this board that without FI, big cubes, ported heads (generally a high flow setup) the bigger TB may not help much at all. I am mostly using the 52mm because that's the bigged TB my stock intake will really support and it was a really good deal.
EDIT: FYI 52mm have demonstrated the ability to support 331 rwhp (~400 fwhp on an A4). The TB is probably not the restriction in this setup as it uses stock heads, N/A and a 210/224 cam.
Last edited by EbeZ28; Feb 7, 2004 at 10:23 AM.
Registered User
Joined: Jul 2001
Posts: 752
From: Double Oak TX
Being you mentioned 331 rwhp.
On a C4 Lt4 I was able to get 331 rwhp with just the usual bolt ons including ram air intake, long tube headers and a dual custom 3" exhaust. This is is with the 48mm TB and a completly stock internal engine.
I bought a 58mm TB and ported my intake to accept it.
The car made........... 331rwhp after dynoing and retuning.
There is your objective proof that a larger TB doesn't help in that hp range. Now at how much hp do you need a larger TB?
That's the $320.00 plus porting question.
On a C4 Lt4 I was able to get 331 rwhp with just the usual bolt ons including ram air intake, long tube headers and a dual custom 3" exhaust. This is is with the 48mm TB and a completly stock internal engine.
I bought a 58mm TB and ported my intake to accept it.
The car made........... 331rwhp after dynoing and retuning.
There is your objective proof that a larger TB doesn't help in that hp range. Now at how much hp do you need a larger TB?
That's the $320.00 plus porting question.
Registered User
Joined: Jan 2000
Posts: 487
From: Lockport, Illinois 60441
Originally posted by Denny McLain
Being you mentioned 331 rwhp.
On a C4 Lt4 I was able to get 331 rwhp with just the usual bolt ons including ram air intake, long tube headers and a dual custom 3" exhaust. This is is with the 48mm TB and a completly stock internal engine.
I bought a 58mm TB and ported my intake to accept it.
The car made........... 331rwhp after dynoing and retuning.
There is your objective proof that a larger TB doesn't help in that hp range. Now at how much hp do you need a larger TB?
That's the $320.00 plus porting question.
Being you mentioned 331 rwhp.
On a C4 Lt4 I was able to get 331 rwhp with just the usual bolt ons including ram air intake, long tube headers and a dual custom 3" exhaust. This is is with the 48mm TB and a completly stock internal engine.
I bought a 58mm TB and ported my intake to accept it.
The car made........... 331rwhp after dynoing and retuning.
There is your objective proof that a larger TB doesn't help in that hp range. Now at how much hp do you need a larger TB?
That's the $320.00 plus porting question.
Registered User
Joined: Aug 2001
Posts: 258
From: Minnesota
I have abotu the same as roughly without the heads.... I really like the 52, I wouldn't go 58 becuse there is no need for me right now.. I don't need to get more air in.. it is getting enough, right now I need to work on getting more fuel in. you will be very happy wiht both but hte 52 will be cheaper and essentially do the same thing
