THE TB mod thread, with all the info and data you need

Fidelity101 · 12-10-2008, 11:13 PM

everyone has rumors and concerns or thoughts and questions about the TB mod, especially on the non turbo ones but I have access to a flow bench

I followed the DIY here
http://fc3spro.com/TECH/HOWTO/TBM/tbm.html

..to a point. I was unsure on weather or not a bolt would be worse than filling it with JB weld and smoothing it to match the TB surface. it makes a good project. Basically going on the theory if there is that hole left there or a gap the airflow would be the same effect as an airplane up in the sky and someone opens a door, the fast air passing over the smooth surfaces will suck out the air inside and cause turbulence, and the only turbulence you want it near the combustion chamber for a better fuel/air mix burn. This is why don't polish the intake side on a cylinder head, keep it a little rough to create turbulence.

here is the elbow I ported

Basically just smoothed out the sharp cut and the ridge on the inlet side.

and here is the TB all mounted and ported and polished. (i'll have better pics of it when its off the car soon to flow)

my project is comparing velocity and CFM increases for these various combinations.

100% stock throttle body with stock intake elbow
stock throttle body with ported elbow above
Shafts removed throttle body with jb weld fix, stock elbow
Shafts removed throttle body with jb weld fix, ported elbow
Shafts removed throttle body with threaded bolt fix, stock elbow
Shafts removed throttle body with threaded bolt fix, ported elbow
^^ all throttle bodies above have no porting or polishing done
fully ported and polished TB with no shafts and stock elbow
fully ported and polished TB with no shafts and ported elbow

.

so as of now stock TB should use the stock elbow, the ported elbow on stock TB does not flow as much at midrange power, the smaller size elbow helps the air charge speed maintain velocity.

the shafts removed increased 67CFM alone, which is huge.

the stock TB flowed 651 CFM (no matter the elbow) and the modified one flowed 719.7/715.2 CFM (ported/stock elbow) but on this one the ported elbow flowed 74.8 CFM more in comparison to the stock elbow.

my driveablity improved, my hesitation went away (my secondaries were sticking) and throttle response improved. I a very big throttle response improvement. with the mods I have the TB mod helped out, I don't know how it will be different on a stock ported engine. at the time I had a s4 streetport on mine with other various goodies. When airflow is concerned it matters for power at the smallest orifice which is your intake port on the iron or your valve area in your cylinder head if any of you have piston engines heh.

here is the data:

throttle bodies are typically flowed on a bench with no elbow on them and measured at WOT and typically flowed at a pressure of 1.5" of HG (mercury)

so I have that on the chart now. so if you see like a 650CFM carb thats what its tested at 1.5" Hg. Considering the more pressure you force air through a given orifice, it will yield more flow. so I could have it tested at an even higher level of inches of water and get more CFM but 25" is the magic number it seems for when people are comparing things to another such as intake manifolds, heads, headers and etc...

this test was basically to see the difference in using a bolt to fill the hole or JB weld and see how P&P affects airflow etc etc. there is a very minimal difference in CFM for the JB weld fix or using a bolt, hell if you dont have a thread and tap kit you can fill it with jb weld then run a bolt through it heh, but that would be redundant.

the velocity was all measured at WOT on the bench with no elbow

you gain more velocity through a smaller port with the same pressure so widening the throttle body lowers the velocity through there but it gives more CFM, its kind of a trade off but looking at the results a ported and polished throttle body is definitely an upgrade in comparison.

so use JB weld or a threaded bolt, your not going to be able to tell the difference unless you ended screwing up and getting a leak :P

Phoenix7 · 12-10-2008, 11:30 PM

this is the coolest thread ever. You rule Fidelity. You cannot get better data than that.

Thanks.

Fidelity101 · 12-10-2008, 11:35 PM

I'm here to help

there is a lot of misinformation on forums people just say things but if you got data to back up statements it becomes factual information.

I had to sell that ported throttle body that is seen above pictures to buy my new motor and right now I am currently working on a new design that I hope to flow test vs this one and compare the two.

here is a teaser:

If I can get a hold of an air compressor for cheap I will start providing porting services for people, and I've ported cylinder heads and other oddities and I have an educational background in engine airflow so you know your getting it done right.

Ender · 12-10-2008, 11:39 PM

kick
ass

No more debate on this! I guess I'll be doing more TB work soon...

Fidelity101 · 12-10-2008, 11:49 PM

This won't increase horsepower (probably) but your intake manifold will fill with air faster, so you can increase your intake velocity.

Whizbang · 12-11-2008, 10:01 AM

Ill be linking this thread in the 2nd gen FAQ.

Flooder · 12-12-2008, 11:00 PM

I did the TB mod on my car and I didn't notice all the BS that most people say happens. Stalling, hard starting, low rpm torque, etc etc. The car drove fine for me. *shrugs*.

drift7 · 12-13-2008, 01:06 AM

i will be doing this mod very very soon

Fidelity101 · 12-14-2008, 10:15 PM

My secondary flaps weren't working properly and I had to fix the primary flaps on the current one I'm working on because they didn't open all the way. So after I did all the work to my throttle body and put it on my car, it ran much better overall. I'm debating boring it out for larger flaps too as well as the matching ports on the s5 UIM.

StarSpeedRacing · 01-14-2009, 03:46 AM

I will probably port one myself but do a mild porting.

Phoenix7 · 01-14-2009, 03:49 AM

Hey fidelity, would you be down to port and flow test a stock TII exhaust manifold?

Fidelity101 · 02-19-2009, 06:52 PM

Probably not but if you wanted to pay for shipping both ways and a "service donation" I could give it a shot.

I'm only unsure of the width of the exhaust port holes on the manifold being too far spread apart for the flowbench.

Also I am working on a new design and I will flow that to see if my new design had any gains.

I just modified an S4 TB and began to port that and I and I have an S5 TB that I just modified and will port and polish in the future and compare them

12-10-2008, 11:13 PM	#1
Fidelity101 Reliable Source Join Date: Nov 2008 Location: Michigan/Illinois iTrader: (1) Posts: 336 Rep Power: 17	THE TB mod thread, with all the info and data you need everyone has rumors and concerns or thoughts and questions about the TB mod, especially on the non turbo ones but I have access to a flow bench I followed the DIY here http://fc3spro.com/TECH/HOWTO/TBM/tbm.html ..to a point. I was unsure on weather or not a bolt would be worse than filling it with JB weld and smoothing it to match the TB surface. it makes a good project. Basically going on the theory if there is that hole left there or a gap the airflow would be the same effect as an airplane up in the sky and someone opens a door, the fast air passing over the smooth surfaces will suck out the air inside and cause turbulence, and the only turbulence you want it near the combustion chamber for a better fuel/air mix burn. This is why don't polish the intake side on a cylinder head, keep it a little rough to create turbulence. here is the elbow I ported Basically just smoothed out the sharp cut and the ridge on the inlet side. and here is the TB all mounted and ported and polished. (i'll have better pics of it when its off the car soon to flow) my project is comparing velocity and CFM increases for these various combinations. 100% stock throttle body with stock intake elbow stock throttle body with ported elbow above Shafts removed throttle body with jb weld fix, stock elbow Shafts removed throttle body with jb weld fix, ported elbow Shafts removed throttle body with threaded bolt fix, stock elbow Shafts removed throttle body with threaded bolt fix, ported elbow ^^ all throttle bodies above have no porting or polishing done fully ported and polished TB with no shafts and stock elbow fully ported and polished TB with no shafts and ported elbow . so as of now stock TB should use the stock elbow, the ported elbow on stock TB does not flow as much at midrange power, the smaller size elbow helps the air charge speed maintain velocity. the shafts removed increased 67CFM alone, which is huge. the stock TB flowed 651 CFM (no matter the elbow) and the modified one flowed 719.7/715.2 CFM (ported/stock elbow) but on this one the ported elbow flowed 74.8 CFM more in comparison to the stock elbow. my driveablity improved, my hesitation went away (my secondaries were sticking) and throttle response improved. I a very big throttle response improvement. with the mods I have the TB mod helped out, I don't know how it will be different on a stock ported engine. at the time I had a s4 streetport on mine with other various goodies. When airflow is concerned it matters for power at the smallest orifice which is your intake port on the iron or your valve area in your cylinder head if any of you have piston engines heh. here is the data: throttle bodies are typically flowed on a bench with no elbow on them and measured at WOT and typically flowed at a pressure of 1.5" of HG (mercury) so I have that on the chart now. so if you see like a 650CFM carb thats what its tested at 1.5" Hg. Considering the more pressure you force air through a given orifice, it will yield more flow. so I could have it tested at an even higher level of inches of water and get more CFM but 25" is the magic number it seems for when people are comparing things to another such as intake manifolds, heads, headers and etc... this test was basically to see the difference in using a bolt to fill the hole or JB weld and see how P&P affects airflow etc etc. there is a very minimal difference in CFM for the JB weld fix or using a bolt, hell if you dont have a thread and tap kit you can fill it with jb weld then run a bolt through it heh, but that would be redundant. the velocity was all measured at WOT on the bench with no elbow you gain more velocity through a smaller port with the same pressure so widening the throttle body lowers the velocity through there but it gives more CFM, its kind of a trade off but looking at the results a ported and polished throttle body is definitely an upgrade in comparison. so use JB weld or a threaded bolt, your not going to be able to tell the difference unless you ended screwing up and getting a leak :P __________________ My Rx-7 Vids

12-10-2008, 11:35 PM	#3
Fidelity101 Reliable Source Join Date: Nov 2008 Location: Michigan/Illinois iTrader: (1) Posts: 336 Rep Power: 17	I'm here to help there is a lot of misinformation on forums people just say things but if you got data to back up statements it becomes factual information. I had to sell that ported throttle body that is seen above pictures to buy my new motor and right now I am currently working on a new design that I hope to flow test vs this one and compare the two. here is a teaser: If I can get a hold of an air compressor for cheap I will start providing porting services for people, and I've ported cylinder heads and other oddities and I have an educational background in engine airflow so you know your getting it done right. __________________ My Rx-7 Vids Last edited by Fidelity101; 12-10-2008 at 11:40 PM..

12-10-2008, 11:49 PM	#5
Fidelity101 Reliable Source Join Date: Nov 2008 Location: Michigan/Illinois iTrader: (1) Posts: 336 Rep Power: 17	This won't increase horsepower (probably) but your intake manifold will fill with air faster, so you can increase your intake velocity. __________________ My Rx-7 Vids

12-11-2008, 10:01 AM	#6
Whizbang Respecognize! Join Date: Jul 2008 Location: Δx = ħ/2Δp iTrader: (5) Posts: 3,190 Rep Power: 20	Ill be linking this thread in the 2nd gen FAQ. __________________ For current updates and event coverage check out Follow on Twitter! @WhizbangRally Whizbang Rally's Webpage \| Facebook

12-12-2008, 11:00 PM	#7
Flooder Rotary Fanatic Join Date: Feb 2008 Location: Tucson, Arizona iTrader: (0) Posts: 321 Rep Power: 17	I did the TB mod on my car and I didn't notice all the BS that most people say happens. Stalling, hard starting, low rpm torque, etc etc. The car drove fine for me. shrugs. __________________ AZRX7.COM Red 1991 A-package(SOLD) Red 1990 GXL(SOLD) White 1989 GTUs(DEAD) Red 1988 Turbo II(DD) Black 1988 Turbo II(SOLD) Rebuilt and street ported motor, Garrett T04E Turbo, 3" Turbo Inlet Duct/AEM Dry Flow Filter, Your Mom's MBC, Blitz FMIC, 890cc and 1000cc injectors, Tomei FPR, Walbro, Rtek 2.1 ECU, Taurus E-Fan, Turbonetics BOV, 3" Motoria/Corksport Turbo Back Exhaust, Emissions Removed, Greddy Boost Gauge, Megan Racing Water Temp Gauge, 5one5 Triple Gauge Pod, AEM Uego, GP Sports Body Kit, Fiber Images CF Hood, S5 Seats, S5 Tails, S5 Alt, Dual Alt Pulley, D2 Coilovers, NRG Quick Release, Shook Motorsports Radiator, HID's, AN/Steel Braided Oil Cooler Lines, SUPER JDM TYTE DRIFT BUTTON www.DensetsuMotorsports.com www.AZRX7.Com www.FloodersAdventure.com

12-13-2008, 01:06 AM	#8
drift7 The Newbie Join Date: Mar 2008 Location: 7th Heaven iTrader: (0) Posts: 3 Rep Power: 0	i will be doing this mod very very soon

12-14-2008, 10:15 PM	#9
Fidelity101 Reliable Source Join Date: Nov 2008 Location: Michigan/Illinois iTrader: (1) Posts: 336 Rep Power: 17	My secondary flaps weren't working properly and I had to fix the primary flaps on the current one I'm working on because they didn't open all the way. So after I did all the work to my throttle body and put it on my car, it ran much better overall. I'm debating boring it out for larger flaps too as well as the matching ports on the s5 UIM. __________________ My Rx-7 Vids

01-14-2009, 03:46 AM	#10
StarSpeedRacing StarSpeedRacing Join Date: Dec 2008 Location: California iTrader: (0) Posts: 34 Rep Power: 0	I will probably port one myself but do a mild porting. __________________ StarSpeedRacing Parts Development & Discount Parts! GB:FD Intercooler Kit GB:Stainless Non Turbo Headers Contact: StarSpeedRacing@gmail.com

02-19-2009, 06:52 PM	#12
Fidelity101 Reliable Source Join Date: Nov 2008 Location: Michigan/Illinois iTrader: (1) Posts: 336 Rep Power: 17	Probably not but if you wanted to pay for shipping both ways and a "service donation" I could give it a shot. I'm only unsure of the width of the exhaust port holes on the manifold being too far spread apart for the flowbench. Also I am working on a new design and I will flow that to see if my new design had any gains. I just modified an S4 TB and began to port that and I and I have an S5 TB that I just modified and will port and polish in the future and compare them __________________ My Rx-7 Vids