Multiple Carb Set Up

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6PAK72
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Multiple Carb Set Up

Post by 6PAK72 » Sat Jan 31, 2009 12:21 pm

Do we have enough snow?

Complex question below:

In the COM ST rules, the carburation paragraph "Original carbureter...must be used". The TR6 was FACTORY stock with (2) Stromberg CV175's, AND was available with (2) SU 175's. However, once in the US dealer channel, many dealers swapped the Strombergs and SU's for (2) Webber DCOE's prior to customer delivery.

The Strombergs and the SU's both mounted to the factory-stock iron intake manifold. The Webbers required an adapter plate to clear the linkage from the hot water recirculator built into the manifold.

Our car is set up for twin Strombergs, AND set up for the Webbers. The TR6 is notorious for running lean at higher RPM, and thus heats up - very bad for a TR. The Webbers solve the problem.

Can I ask for a ruling on the swap?

THanks very much!
Jeff Baker
Wilton, NH
#42 95 Miata
72 TR6
79 TR7 V6 in shed

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Stynger
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Re: Multiple Carb Set Up

Post by Stynger » Sat Jan 31, 2009 8:35 pm

Didn't we decide your car is not an ST car due to engine mods? :shock:
Les.

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chaos4NH
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Re: Multiple Carb Set Up

Post by chaos4NH » Sun Feb 01, 2009 1:09 am

I believe so Les. The Weber would also push it into SP, in any case.
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StephanAlfa
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Re: Multiple Carb Set Up

Post by StephanAlfa » Tue Feb 03, 2009 6:20 pm

chaos4NH wrote:I believe so Les. The Weber would also push it into SP, in any case.
NO. You can change intake + exhaust in ST... but because he has other mods ST for him would not apply aynway...
Stephan de Pénasse - Classroom Instructor - http://www.comscc.org
2001 BMW 330i Sports Package (T-60 Class)

betelgeuse
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Re: Multiple Carb Set Up

Post by betelgeuse » Tue Feb 03, 2009 8:16 pm

Street Touring rule 5a.

Any air cleaner may be used. Original carburetor or fuel injection throttle body (or OEM equivalent with same flow rate) must be used. In all cases, intake manifold and airflow sensors must remain stock as delivered.

This is out of the 08 rule book.

Greg
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chaos4NH
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Re: Multiple Carb Set Up

Post by chaos4NH » Tue Feb 03, 2009 8:49 pm

betelgeuse wrote:Street Touring rule 5a.

Any air cleaner may be used. Original carburetor or fuel injection throttle body (or OEM equivalent with same flow rate) must be used. In all cases, intake manifold and airflow sensors must remain stock as delivered.

This is out of the 08 rule book.

Greg


That is correct. Only the air intake system prior to the carbs/throttle body may be changed for ST classes.

However, since it seems that the car, as configured, would be in SPB, the webers would be allowed.
Sam
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6PAK72
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Re: Multiple Carb Set Up

Post by 6PAK72 » Wed Feb 04, 2009 9:11 pm

Thank you for the clarifications.

Since we're classed SP-B, I've got another issue.

The car has stock seats, and 3-points. If I read correctly, the SP-class requires 5-point harness, which would require changes to the floorpan at least, and perhaps a replacement of the transmission cover.

Thoughts?

Thanks again,
Jeff Baker
Wilton, NH
#42 95 Miata
72 TR6
79 TR7 V6 in shed

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chaos4NH
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Re: Multiple Carb Set Up

Post by chaos4NH » Wed Feb 04, 2009 9:33 pm

6PAK72 wrote:Thank you for the clarifications.

Since we're classed SP-B, I've got another issue.

The car has stock seats, and 3-points. If I read correctly, the SP-class requires 5-point harness, which would require changes to the floorpan at least, and perhaps a replacement of the transmission cover.

Thoughts?

Thanks again,

Somehow you have an older set of rules. We changed them to allow stock belts for SP cars.
quoting: SS, ST and SP cars may use any DOT, SFapproved harness.I, or FIA
DOT is meant to mean stock lap and shoulder belts, the word harness may be throwing you off.
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6PAK72
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Was Carbs, now belts

Post by 6PAK72 » Wed Feb 04, 2009 10:54 pm

Thank you for the clarification. I thought I had seen that in last year's posts, so I am downloading a new set of rules now.

Rollbar is in and clear, seats lock solid, arm restraints fitted.

We having fun at 4 degrees?
Jeff Baker
Wilton, NH
#42 95 Miata
72 TR6
79 TR7 V6 in shed

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chaos4NH
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Re: Was Carbs, now belts

Post by chaos4NH » Wed Feb 04, 2009 11:06 pm

6PAK72 wrote:Thank you for the clarification. I thought I had seen that in last year's posts, so I am downloading a new set of rules now.

Rollbar is in and clear, seats lock solid, arm restraints fitted.

We having fun at 4 degrees?
Heat wave in Merrimack. 8 degrees
Sam
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#41 Nissan 200SX SER T40

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