TPI Tuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
Sponsored by:
Sponsored by:

Would you guys upgrade to a larger throttle body?

Thread Tools
 
Search this Thread
 
Old 05-22-2017, 07:03 PM
  #1  
Moderator

Thread Starter
iTrader: (3)
 
Abubaca's Avatar
 
Join Date: Feb 2001
Location: JAMESTOWN, NC
Posts: 8,366
Received 348 Likes on 275 Posts
Car: 1988 Iroc
Engine: L98 350
Transmission: 700R4
Axle/Gears: Hawks 8.8 - 3.73
Would you guys upgrade to a larger throttle body?

What's up guys. I'm running a 383, RHS 180 heads, 223/227 Voodoo cam, Darin Dochterman ported stock base, cut open/ported/welded SLP runners, SLP 1.75 headers, etc. etc. .....and a stock TB.

The senior members will remember the days of arguing over aftermarket TB's and all the guys swearing their stock LB9 cars picked up .5 a second with a 52mm, and all that crap. I'm so set in my mind that it's a waste of money and not worth it. I feel like I've been through the aftermarket TB exercise over and over, and I know my stuff ...BUT.....somewhere along the way, I picked up heads, a cam, and 33 extra inches, and now I'm wondering if maybe it's worth picking up. Maybe my TPI 101 knowledge has gotten lazy over the years having moved past the basics almost 15 years ago. Perhaps my Kung Fu has gotten weak, and I need to hit the gym.

Should I pick up a TB???
Old 05-22-2017, 07:11 PM
  #2  
Sponsor

iTrader: (92)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 15,407
Received 649 Likes on 573 Posts
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Would you guys upgrade to a larger throttle body?

Look at the ramjet 502 it has a stock 48mm. Aftermarket bling is nice but there's better bang for your buck out there.i could see wot gains but is it worth the money I'd say no. Just my two cents.
Old 05-22-2017, 07:55 PM
  #3  
Supreme Member
iTrader: (1)
 
thtanner's Avatar
 
Join Date: May 2015
Location: Temecula, CA
Posts: 1,149
Received 83 Likes on 67 Posts
Car: 1989 Pontiac Formula 350
Engine: L98
Transmission: 700R4
Axle/Gears: BorgWarner 3.27 Posi
Re: Would you guys upgrade to a larger throttle body?

Only reason I bought a 52mm for my build is because it was a nice, new TB, vs my 150k OE one. I don't expect performance gains from the TB really. It's just nice to look at.
Old 05-22-2017, 08:09 PM
  #4  
Moderator

Thread Starter
iTrader: (3)
 
Abubaca's Avatar
 
Join Date: Feb 2001
Location: JAMESTOWN, NC
Posts: 8,366
Received 348 Likes on 275 Posts
Car: 1988 Iroc
Engine: L98 350
Transmission: 700R4
Axle/Gears: Hawks 8.8 - 3.73
Re: Would you guys upgrade to a larger throttle body?

Look at the ramjet 502 it has a stock 48mm.
...that's always been my argument too. -BUT, I know not every decision at GM is made around peak performance. Again, for a stock/modded 350, I never swapped. Just wondered if maybe with a 383 it would show a gain. I still feel the TPI, hogged out as it is, is still the bottleneck. Man it's violent beast outta the hole. Then it's done. lol.
Old 05-22-2017, 08:12 PM
  #5  
Senior Member

 
tealman92's Avatar
 
Join Date: Mar 2002
Location: Ontario, California
Posts: 998
Received 19 Likes on 16 Posts
Car: 1992 Z28
Engine: 383
Transmission: 700R4
Re: Would you guys upgrade to a larger throttle body?

Have you dynoed your current set up with the stock tb?
Old 05-22-2017, 10:02 PM
  #6  
Moderator

Thread Starter
iTrader: (3)
 
Abubaca's Avatar
 
Join Date: Feb 2001
Location: JAMESTOWN, NC
Posts: 8,366
Received 348 Likes on 275 Posts
Car: 1988 Iroc
Engine: L98 350
Transmission: 700R4
Axle/Gears: Hawks 8.8 - 3.73
Re: Would you guys upgrade to a larger throttle body?

Nah, not yet. I just got the car up and running a few months ago. The Holley EFI did a great job of self tuning, and I've been learning the software and how to tune with basic tweaking etc. etc. I'm about to start looking for more power in the tune, but it definitely runs great now. I had some "butt dyno" expectations, and thus far it hasn't disappointed. The thing that got my attention was that it's running out of breath right at 5k. I know it's a 383, with a long tube set up, but I really felt there'd be a little more. Factory tach is off, and until I really looked at some WOT runs on the datalog, I didn't realize it was "only" running to about 5000/5100. I know that's about right, but....had hoped for a little more.
Old 05-24-2017, 05:24 PM
  #7  
Supreme Member

 
cuisinartvette's Avatar
 
Join Date: Feb 2006
Location: Sanctuary state
Posts: 1,780
Likes: 0
Received 27 Likes on 24 Posts
Car: 67 ******mobile
Engine: 385 Solid roller
Transmission: T-56
Axle/Gears: 4.11
Re: Would you guys upgrade to a larger throttle body?

I still feel the TPI, hogged out as it is, is still the bottleneck
yup...and you are right waste of money
Old 05-24-2017, 05:30 PM
  #8  
Member

iTrader: (4)
 
zya5point0's Avatar
 
Join Date: Jul 2004
Location: pa
Posts: 472
Received 7 Likes on 7 Posts
Car: 87 IROC
Engine: 350
Transmission: auto
Axle/Gears: 3.23
Re: Would you guys upgrade to a larger throttle body?

I've always looked at it a couple ways... First, until somebody shows dyno evidence it hurts performance, I like the coolness factor Plus, back in the day, Lingenfelter was one of the first TPI gurus. If he used it on all his built motors, it must have been deemed necessary at some point, right?
Old 05-24-2017, 06:23 PM
  #9  
Supreme Member

iTrader: (7)
 
Dyno Don's Avatar
 
Join Date: Mar 2000
Location: Orange, CA
Posts: 5,674
Likes: 0
Received 106 Likes on 65 Posts
Car: '90 Trans Am-12.45@110.71
Engine: 355 w/AFR 195's Elem. 400/430 HP/TQ
Transmission: Tremec T-56
Axle/Gears: 12 Bolt 3.73
Re: Would you guys upgrade to a larger throttle body?

I once had a computer program that would allow me to change intake flow numbers
runner length, cu.in. and cam specs. Then it would show max air flow thru the motor.
The most I could get it to flow with a 355 230-230 cam 200cc heads, intake that flowed
320 CFM per runner was 760 CFM total.
So with your combo.....waste of money.
HTH
Old 05-24-2017, 09:21 PM
  #10  
Supreme Member

iTrader: (2)
 
Tootie Pang's Avatar
 
Join Date: Aug 2009
Location: Los Angeles
Posts: 1,972
Received 124 Likes on 91 Posts
Car: 1989 IROC Convertible
Engine: 350 TPI L98
Transmission: WC T5
Axle/Gears: 3.42
Re: Would you guys upgrade to a larger throttle body?

Stock TB is good for at least 400 HP according to a 58mm BBK test Super Chevy ran a while ago. I.e. There was no difference in power made.
Old 05-24-2017, 09:57 PM
  #11  
Supreme Member

 
Buddy's Avatar
 
Join Date: May 2001
Location: Kars, Ontario, Canada
Posts: 1,259
Received 68 Likes on 58 Posts
Car: '87 FIREGOOSE!!!!
Re: Would you guys upgrade to a larger throttle body?

Originally Posted by zya5point0
I've always looked at it a couple ways... First, until somebody shows dyno evidence it hurts performance, I like the coolness factor Plus, back in the day, Lingenfelter was one of the first TPI gurus. If he used it on all his built motors, it must have been deemed necessary at some point, right?
LOL, I was gonna post the same thing, John Lingenfelter was the MAN!!! He dynoed every part to squeeze out every hp he could, and everything he touched backed up his word. He included 52mm TB's in his packages. And the guy knew his stuff, better than most anybody.
Old 05-25-2017, 12:16 AM
  #12  
Senior Member

 
tealman92's Avatar
 
Join Date: Mar 2002
Location: Ontario, California
Posts: 998
Received 19 Likes on 16 Posts
Car: 1992 Z28
Engine: 383
Transmission: 700R4
Re: Would you guys upgrade to a larger throttle body?

He wouldn't be the first business man to sell you something you don't need. If it added a .2 hp hell put it in our package and bump the price. This has been proven time and time again a 52mm or 58mm tb had no advantage over a stock tb.
Old 05-25-2017, 12:39 AM
  #13  
Supreme Member

iTrader: (2)
 
Tootie Pang's Avatar
 
Join Date: Aug 2009
Location: Los Angeles
Posts: 1,972
Received 124 Likes on 91 Posts
Car: 1989 IROC Convertible
Engine: 350 TPI L98
Transmission: WC T5
Axle/Gears: 3.42
Re: Would you guys upgrade to a larger throttle body?

Same story on the Mustang 5.0's back in the day. No performance gain but cool to have.




All times are GMT -5. The time now is 11:13 PM.