SaturnFans.com
what's new (beta) - classifieds - forums - photos


Go Back   SaturnFans.com Forums > Reference Forums > Mods and Performance
Register FAQ Members List Groups Calendar Chat Room Search Today's Posts Mark Forums Read

 
 
Thread Tools Display Modes
Old 04-16-2002, 12:41 PM   #1
newt
Advanced Member
newt is on a distinguished road
 
Join Date: Jan 2001
Location: Blaine, Minnesota
Posts: 597
 
Default Throttle body mod

This isn't a new idea or anything, but I thought I'd take some before and after measurements to add a little validation...

I think some guys on this board have done this already and the monster throttle body on my Corrodo has these little details as well.

I disassembled the 55mm XRC throttle body and milled down the top and bottom of the throttle plate axle, countersunk the screw holes a bit more and ground off the tips of the screws on the other side of the axle. All of this work got me quite a bit of an increase in cross sectional area. I figured the only position that really matters is WOT. In this position, the throttle plate is horizontal and the screws holding the plate are vertical. I grabbed a micrometer and caliper and started making a wireframe diagram of the throttle body (not on company time, of course ) Then I had the CAD system tell me the cross-sectional area of the throttle body. I also figured out what the cross-sectional area would be for the stock 50mm throttle body. Then I disassembled the TB and fixtured it up in the vertical mill. I used a 19/64" diameter end mill and removed 0.062" from the top of the axle across a span of 1.885". I flipped the setup for the other side of the axle and did the same. Then I countersunk the 2 screw holes a little deeper, assembled the throttle plate and then ground off the tips of the screws. I also bevelled the edge of the throttle plate to help airflow a little, but that part doesn't affect the total capacity of the TB.

So after all that was done, I compared the CAD analyses. The stock 50mm throttle body cross-sectional area came out to be 2.27112 sq. in.

The XRC 55mm throttle body came out at 2.86588 sq. in.

The modified XRC 55mm throttle body came out at 3.12506 sq. in.

So, from stock to XRC is a 26.2% increase.
From XRC to my modified TB is a 9.0% increase.
From stock to modified XRC is 37.6% increase. Not too shabby.

Not that cross-sectional area says anything about laminar airflow and whatnot, but at WOT the overall capacity has increased. I'm sure there's a trade-off in velocity and therefore a drop in low end torque, but with everything I've done to the engine so far, this will further help the top end. The somewhat calibrated butt-dyno proves it out too. I took a bunch of pictures, but all I have is a 35mm camera (pfffft...non-digital...). I'll scan some in after I get them developed.


Fun experiment anyway...

-Wayne

REWARD EXCELLENCE!

Add to newt's Reputation
Rate the quality of this post and help newt reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
newt is offline  
SaturnFans.com Sponsored Links
Old 04-16-2002, 02:15 PM   #2
saturnal1
Member
saturnal1 is on a distinguished road
 
saturnal1's Avatar
 
Join Date: Feb 2000
Location: Lovely Minnesota
Posts: 273
Default

Newt,
Glad to hear you are still messing around with your Saturn in new and experimental ways. Those mods you did to the TB seem very interesting. The increased cross-sectional area will definitely help your top end out, but like you mentioned it will more than likely affect bottom-end torque in a negative way. For your high-flow engine this will only be a good thing, though. Did you ever have the intake manifold bored out? Since your head has been worked on it will flow well, but you never mentioned any work done to the intake manifold. That would be the only bottle-neck I can see for your whole engine at this point. When are you going to dyno that thing???

BTW, you remind me of a mad professor. The only thing missing is the white hair and jerky hand movements.

Also, I finished installing the Phantom Grip and drove the car to work today. No leaks and no squeaks! I'm going to be fairly easy on the tranny for about a week before I really try the PG out. The tranny I installed only has about 4k miles on it and from shifting I can tell that it's still very fresh.

Alex Plaster
97 SC2

REWARD EXCELLENCE!

Add to saturnal1's Reputation
Rate the quality of this post and help saturnal1 reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
saturnal1 is offline  
Old 04-16-2002, 02:46 PM   #3
newt
Advanced Member
newt is on a distinguished road
 
Join Date: Jan 2001
Location: Blaine, Minnesota
Posts: 597
 
Default

Hey Alex,

Good to hear the tranny is working!

When BSR did all of the head work, they hogged out the intake manifold as well. There was enough material removed that the intake gasket had to be trimmed during the part matching process. The 55mm throttle body was port matched to the intake manifold as well, but I had done most of that myself prior to the rebuild. I had to enlarge the hole in the TB gasket quite a bit in order to allow them to match up. The header and exhaust ports were port matched at BSR as well. Basically, Kurt had half of my engine compartment!

I'm still waiting for one connector to complete the Oz DIY wideband A/F meter project. I want to lean the mixture out a bit before I spin the rollers.

See ya,

-Wayne

REWARD EXCELLENCE!

Add to newt's Reputation
Rate the quality of this post and help newt reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
newt is offline  
Old 04-16-2002, 03:03 PM   #4
saturnal1
Member
saturnal1 is on a distinguished road
 
saturnal1's Avatar
 
Join Date: Feb 2000
Location: Lovely Minnesota
Posts: 273
Default

So does this mean you're about ready for the "test-n-tune" phase? It seems like you are pretty much at the limits of building the engine/tranny up. I'm very interested in seeing what numbers your car will put out on the dyno.

Unfortunately for me, I have to pack for my move which is only a few weekends away otherwise I'd head over to Rock Falls to get some 1/4 mile numbers for my car now that it's all put back together.

Alex Plaster
97 SC2

REWARD EXCELLENCE!

Add to saturnal1's Reputation
Rate the quality of this post and help saturnal1 reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
saturnal1 is offline  
Old 04-16-2002, 04:33 PM   #5
Tycho
Senior Member
Tycho is on a distinguished road
 
Tycho's Avatar
 
Join Date: Jun 2001
Location: Fairbanks, Alaska
Posts: 1,219
 
Default

Newt...take it a step furthur...I just bored out my stock TB to 52.5 (hitting vaccume lines...I'm gonna plug em and go out to 56 all the way through this summer)...but I got the T Plate spindle down to nothin...check it

http://homepage.mac.com/dgiessel/.Pi...ramair/tbo.jpg
http://homepage.mac.com/dgiessel/.Pi...ramair/tbc.jpg
http://homepage.mac.com/dgiessel/.Pi...ramair/tbb.jpg

Just take the whole top off the thing.


...
Forced induction is rape.

REWARD EXCELLENCE!

Add to Tycho's Reputation
Rate the quality of this post and help Tycho reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Tycho is offline  
Old 04-17-2002, 09:27 AM   #6
newt
Advanced Member
newt is on a distinguished road
 
Join Date: Jan 2001
Location: Blaine, Minnesota
Posts: 597
 
Default

Cool! Tycho, I had a feeling you were the one to do this mod...

So you just took the whole top of the axle off--I never thought of that! Good idea!

REWARD EXCELLENCE!

Add to newt's Reputation
Rate the quality of this post and help newt reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
newt is offline  
Old 06-13-2002, 01:14 PM   #7
newt
Advanced Member
newt is on a distinguished road
 
Join Date: Jan 2001
Location: Blaine, Minnesota
Posts: 597
 
Default Finally--photos!

I finally got my pictures developed of the throttle body axle/plate modifications. I'll post a couple in case anyone is interested.

-Wayne

(I'll start with the "before" shots first...)
Attached Images
File Type: jpg tbpartsbefore1.jpg (17.2 KB, 45 views)

REWARD EXCELLENCE!

Add to newt's Reputation
Rate the quality of this post and help newt reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
newt is offline  
Old 06-13-2002, 01:24 PM   #8
newt
Advanced Member
newt is on a distinguished road
 
Join Date: Jan 2001
Location: Blaine, Minnesota
Posts: 597
 
Default Viola!

After...
Attached Images
File Type: jpg tbpartsafter1.jpg (13.0 KB, 45 views)

REWARD EXCELLENCE!

Add to newt's Reputation
Rate the quality of this post and help newt reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
newt is offline  
Old 06-13-2002, 01:25 PM   #9
newt
Advanced Member
newt is on a distinguished road
 
Join Date: Jan 2001
Location: Blaine, Minnesota
Posts: 597
 
Default

After #2...
Attached Images
File Type: jpg tbpartsafter2.jpg (11.7 KB, 31 views)

REWARD EXCELLENCE!

Add to newt's Reputation
Rate the quality of this post and help newt reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
newt is offline  
Old 06-13-2002, 01:27 PM   #10
newt
Advanced Member
newt is on a distinguished road
 
Join Date: Jan 2001
Location: Blaine, Minnesota
Posts: 597
 
Default Assembled shots...

After reassembly...
Attached Images
File Type: jpg tbassy2.jpg (18.1 KB, 31 views)

REWARD EXCELLENCE!

Add to newt's Reputation
Rate the quality of this post and help newt reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
newt is offline  
Old 06-13-2002, 01:29 PM   #11
newt
Advanced Member
newt is on a distinguished road
 
Join Date: Jan 2001
Location: Blaine, Minnesota
Posts: 597
 
Default

Another view after reassembly...
Attached Images
File Type: jpg tbassy3.jpg (16.9 KB, 23 views)

REWARD EXCELLENCE!

Add to newt's Reputation
Rate the quality of this post and help newt reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
newt is offline  
Old 06-13-2002, 01:30 PM   #12
newt
Advanced Member
newt is on a distinguished road
 
Join Date: Jan 2001
Location: Blaine, Minnesota
Posts: 597
 
Default

Yet another shot...
Attached Images
File Type: jpg tbassy4.jpg (18.4 KB, 22 views)

REWARD EXCELLENCE!

Add to newt's Reputation
Rate the quality of this post and help newt reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
newt is offline  
Old 06-13-2002, 01:31 PM   #13
newt
Advanced Member
newt is on a distinguished road
 
Join Date: Jan 2001
Location: Blaine, Minnesota
Posts: 597
 
Default

Last one--I promise...
Attached Images
File Type: jpg tbassy5.jpg (17.6 KB, 28 views)

REWARD EXCELLENCE!

Add to newt's Reputation
Rate the quality of this post and help newt reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
newt is offline  
Old 06-13-2002, 05:46 PM   #14
SIYAM
Advanced Member
SIYAM is on a distinguished road
 
Join Date: Feb 2000
Location: www.qksltwo.com
Posts: 842
Default

A long time ago... I did a lil writeup on my site about how to do this. I didn't do as nice a job as wayne... b/c I don't have those special tools. But I've always said that the TB makes more dif. than any of the other bolt ons imho.

Ian

...
http://www.qksltwo.com

REWARD EXCELLENCE!

Add to SIYAM's Reputation
Rate the quality of this post and help SIYAM reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
SIYAM is offline  
 



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
throttle body mod jpstoner S-Series Mods 35 03-26-2009 09:46 PM
Throttle sticks - not throttle body - help! dannysm213 S-Series Tech 2 12-10-2006 04:20 PM
throttle body how far? irondiezl3 S-Series Tech 1 11-12-2006 09:40 PM
ground effects / body mod Elmo Miscellaneous Tech 3 10-02-2000 06:20 PM
ground effects / body mod Elmo Suggestion Box 0 09-29-2000 03:15 PM


All times are GMT -5. The time now is 04:09 PM.

Advanced Forum Search | Advanced Photo Search


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
SaturnFans.com. The Saturn Enthusiasts Site.