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Individual Throttle Bodies


npdougie
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I have a 95 Tercel i race in citrus races   I'm trying to conform to chump car points so i can do a couple east coast races next year,  I have put a set of gsxr throttle bodies on just because well i had them and always wanted to use them on something.  now does this mean it is 100 points aka manifold-50 throttle body mod-50 or 250 points?  because I'm SOL if it 50 each.  Also why is a 95 Tercel 275 points?  has anyone ever driven one  its very slow.  yes i have weight on my side and it handles amazing but its no match for any car on the vpi list that is anywhere near 275 points.

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2 minutes ago, npdougie said:

I have a 95 Tercel i race in citrus races   I'm trying to conform to chump car points so i can do a couple east coast races next year,  I have put a set of gsxr throttle bodies on just because well i had them and always wanted to use them on something.  now does this mean it is 100 points aka manifold-50 throttle body mod-50 or 250 points?  because I'm SOL if it 50 each.  Also why is a 95 Tercel 275 points?  has anyone ever driven one  its very slow.  yes i have weight on my side and it handles amazing but its no match for any car on the vpi list that is anywhere near 275 points.

To answer your question, I do not recall seeing a Tercel entered into any of the events I have run in the last 6 years.  Not saying there aren't any out there, but the amount would be minuscule. 

 

Send an email to: Phil.McKinney@chumpcar.com he is our national tech chief and will give you the true answer regarding ITB's.  As for your starting value, I agree with you that the value is too high, I would send an email to Phil with informaiton regarading the platforms HP/WT in stock form, fuel capacity, and in general any other things about the platform that you feel could make the case to have its value lowered, also compare it to similar cars on the list and their performance.  CC that email to: Michael.Chisek@chumpcar.com the organizations COO as well.

 

Both are very receptive, however expect at least a 48hr response time from Mike(how long it took with my last email), and possibly longer from Phil. 

 

Good luck!

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2 hours ago, npdougie said:

Also why is a 95 Tercel 275 points?  has anyone ever driven one  its very slow.  yes i have weight on my side and it handles amazing but its no match for any car on the vpi list that is anywhere near 275 points.

 

2 hours ago, hotchkis23 said:

Send an email to: Phil.McKinney@chumpcar.com he is our national tech chief. As for your starting value, I agree with you that the value is too high, I would send an email to Phil with information regarding the platforms HP/WT in stock form, fuel capacity, and in general any other things about the platform that you feel could make the case to have its value lowered, also compare it to similar cars on the list and their performance.  CC that email to: Michael.Chisek@chumpcar.com the organizations COO as well.

 

Make a table with weight, power, Cd, fuel tank size, notes on suspension, etc. with columns for the tercel and other similar cars on the list. A direct comparison table is probably the easiest way to show how this car will compare to others on the VPI table. Make sure that you include the 2nd gen toyota MR2 on the comparison table... at 200 points, a comparison to that car will pull your new Tercel value way down.

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Unfortunately, we retired the FX-16 in 2013.  I have no idea what it would take to campaign one under today's rules.  Our corolla was fast...in 2010.  By 2013 it was on the bottom end of the speed curve.  I miss it but it was not competitive even then.  I can't believe a Tercel would be either, but rules are written for a broad group of cars.  What about ITBs on a Mustang?   Dangerous territory.   

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1 hour ago, Jer said:

Unfortunately, we retired the FX-16 in 2013.  I have no idea what it would take to campaign one under today's rules.  Our corolla was fast...in 2010.  By 2013 it was on the bottom end of the speed curve.  I miss it but it was not competitive even then.  I can't believe a Tercel would be either, but rules are written for a broad group of cars.  What about ITBs on a Mustang?   Dangerous territory.   

Same as triple webers on a 240Z ...

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1 hour ago, Eman911 said:

image.jpeg.75ce5308f9e63437461fbdc580cb67fd.jpeg

 

How much fuel can a Mustang get?

 

 Beautiful, and more power with less fuel.  

 

Ford numbers the cylinders front to back 1-4 on the passenger side and 5-8 on the driver side.  There are fuel injectors at each inlet runner but the air is from a central throttle body.  Therefore cylinders 1, 4, 5, ,8 get less air being further away from the throttle body while 2, 3, 6, 7 get more air.  

 

The O2 sensor is on one exhaust pipe so it averages the gases from the four cylinders.  So the center 4 cylinders run lean while the outer 4 run rich.  Metering both air and fuel for each cylinder will run each one at the optimum ratio making more power using less fuel.  

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Yeah i sent an email to no response a while ago.  I will make another.  As for speed,  our best lemons after 3 races was 14th.  We beat a few teams that were at the chump race in Thompson ct   (I raced in a golf), we are closing in on speed and we still have a a bad transmission with a horrible 3.72 final that i accidentally put in from and older model.  With the correct final drive we should be much quicker.  Should easily be competitive in class A

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  • ChampCar Staff

 

I was running these on my Factory Five. Nice to look at, but an amazing PITA to tune. You had to manually balance the air flow, then go into the computer to work the data tables. Plus, since each throttle was individual you could only run a Speed Density system not Mass Air. But it sure did look good...

 

 

IMG_1864.thumb.JPG.1ed8bd944cdf0458fc02472738cfd8d7.JPG 

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1 hour ago, DuncanDana said:

 

I was running these on my Factory Five. Nice to look at, but an amazing PITA to tune. You had to manually balance the air flow, then go into the computer to work the data tables. Plus, since each throttle was individual you could only run a Speed Density system not Mass Air. But it sure did look good...

 

 

IMG_1864.thumb.JPG.1ed8bd944cdf0458fc02472738cfd8d7.JPG 

Not that you would have to worry too much, but be aware that using foam on those stack filters can eat up some hp.

644515.jpg

 

Did an LS 6.2 in a '30 Model A for a customer with the ITBs and domed foam filters that made 520 hp on the engine dyno. When the engine was in the car with the filters he liked, it made 320 whp. Removed the filters and it went up to 380 whp. I'm designing him a different air filter assembly.

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1 hour ago, DuncanDana said:

 

I was running these on my Factory Five. Nice to look at, but an amazing PITA to tune. You had to manually balance the air flow, then go into the computer to work the data tables. Plus, since each throttle was individual you could only run a Speed Density system not Mass Air. But it sure did look good...

 

 

IMG_1864.thumb.JPG.1ed8bd944cdf0458fc02472738cfd8d7.JPG 

 

With ITB’s speed density probably isn’t a great choice either, most people use alpha n. MS has an ITB mode that used alpha n up to a predetermined throttle opening then transitions to speed density, I  have never used it but the people who have used seem to agree that it is much better than either mode by itself.

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1 hour ago, mender said:

Not that you would have to worry too much, but be aware that using foam on those stack filters can eat up some hp.

 

 

Did an LS 6.2 in a '30 Model A for a customer with the ITBs and domed foam filters that made 520 hp on the engine dyno. When the engine was in the car with the filters he liked, it made 320 whp. Removed the filters and it went up to 380 whp. I'm designing him a different air filter assembly.

 

Yea, it sucked the foam right out of the screens in the first week! I ended up just painting the screens and leaving them alone. The kept out birds, small children, and low flying airplanes, but that's about it..

 

 

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  • 3 months later...
On 11/9/2017 at 10:09 AM, DuncanDana said:

 

Yea, it sucked the foam right out of the screens in the first week! I ended up just painting the screens and leaving them alone. The kept out birds, small children, and low flying airplanes, but that's about it.

The ones I used that ate 60 hp had the cotton K&N style filter media.

 

So did anyone get an answer about the points value for a set of ITBs or Webers? Is it 50 points for the intake then 50 points per carb/ITB?

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9 hours ago, mender said:

The ones I used that ate 60 hp had the cotton K&N style filter media.

 

So did anyone get an answer about the points value for a set of ITBs or Webers? Is it 50 points for the intake then 50 points per carb/ITB?

 

Realistically, it should not be more points than a forced induction setup...........it should be the same or less IMO. 

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10 hours ago, mender said:

The ones I used that ate 60 hp had the cotton K&N style filter media.

 

So did anyone get an answer about the points value for a set of ITBs or Webers? Is it 50 points for the intake then 50 points per carb/ITB?

 

I would call it 50 points for manifold, and 50 points for carb system no matter how many units you need to make up the system.

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 Funny. Many of us look at the same stuff.  I am doing patent search now for a filter system for these  Downdraft ITBs ,street rod style. 

  I n order to keep the cool look , I have designed  an air box to receive  two  flat style filters to fit under the  TBs.    These would take some power away for sure and have some limits on  intake velocity .   I will need to have some size of plenum  under the filters  to soften the intake pulses, and I have not done any calculations as to how  many CI air box i need.

I  am still in the provisional area  and have not actually built one yet.   I want to use the old school  Buick/Olds can am intake look for my TVR .  I wanted to use a tube throttle, but dust kills them so will use typical plates.  If you talk to old CAN Am techs they had to swap plugs every session and lap the valves often until they used the air boxes with water /dirt" exclusion bends "in them .  

     As far as points. It should be the same as any other intake mod. IMHO.    

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1 hour ago, Ogren-Engineering said:

 Funny. Many of us look at the same stuff.  I am doing patent search now for a filter system for these  Downdraft ITBs ,street rod style. 

  I n order to keep the cool look , I have designed  an air box to receive  two  flat style filters to fit under the  TBs.    These would take some power away for sure and have some limits on  intake velocity .   I will need to have some size of plenum  under the filters  to soften the intake pulses, and I have not done any calculations as to how  many CI air box i need.

I  am still in the provisional area  and have not actually built one yet.   I want to use the old school  Buick/Olds can am intake look for my TVR .  I wanted to use a tube throttle, but dust kills them so will use typical plates.  If you talk to old CAN Am techs they had to swap plugs every session and lap the valves often until they used the air boxes with water /dirt" exclusion bends "in them .  

     As far as points. It should be the same as any other intake mod. IMHO.    

You'll lose a bunch of the resonance effect on the stacks but if it's for show the loss of go shouldn't worry the customer.

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I picked up some awesome cast aluminum oval air cleaner(s) for my 48IDA setup back when I was running rotaries... IIRC they were originally designed for a dual carb VW setup.  I used a round K&N element with the right circumference "squashed" to fit.

 

These guys:

1118524.jpg.a8dd85ff73c13c15c90a68840a4f69a5.jpg

 

Completely irrelevant to your actual post, but I miss my rotary days :lol:

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  • 2 months later...

Has this been resolved? Is the 4-cylinder ITB conversion 50 (throttle/manifold), 100 (throttle+manifold), 200 (4 throttles), or 250 (4 throttles+manifold) vpi? Does the "triple Weber" inline 6 get hit with 50 (carbs/intake), 100 (carbs+manifold), 150 (3 carbs), 200 (3 carbs+manifold), 300 (6 butterflies), or 350 (6 butterflies+manifold) vpi?

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