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PostPosted: Mon Oct 28, 2019 6:48 am 
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There shouldn't be that much variation from the engine on the line. Like the Acura Integra has one size for the base engine in FP, and two for the higher performance engines. There shouldn't be multiple options for the same engine spec line.

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PostPosted: Mon Oct 28, 2019 7:29 am 
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Brett W wrote:
There shouldn't be that much variation from the engine on the line. Like the Acura Integra has one size for the base engine in FP, and two for the higher performance engines. There shouldn't be multiple options for the same engine spec line.

And there-in lies the problem, things people think are correct, but are not entirely correct. The two non-VTEC B18 powered Integra's in FP, there's two different TB sizes, and are correctly listed as such. Their two VTEC having brothers, also have different TB sizes. And then there's the Type R, with yet a third dimension. Luckily in this instance, they at least all have their own unique spec line in Prod.

Finding the TB sizes for some of the more obscure Limited Prep stuff in Prod, is what's really the hard part. Stock TB bore for a "Alfa Romeo Alfetta GT & Alfetta Sedan (75-79)"...?

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PostPosted: Mon Oct 28, 2019 8:03 am 
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kruck wrote:
Finding the TB sizes for some of the more obscure Limited Prep stuff in Prod, is what's really the hard part. Stock TB bore for a "Alfa Romeo Alfetta GT & Alfetta Sedan (75-79)"...?


Following this thread, a thought came to mind reading the, what are the TB diameters. Curtis Wood drives a Alfa Spider prepped for F prod. Maybe asking prod car owners to verify thru vehicle tech data and provide the TB size for their prod cars would get some usable numbers. :think:

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PostPosted: Mon Oct 28, 2019 8:13 am 
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Or make them all smaller than humanly possible, bust people for non stock TB sizes and make them prove the spec line wrong in the TECH shed. HAHA. :lol:

Yeah, probably just asking the competitor to provide documentation of the TB size or even bring a stock TB to impound would be more reasonable and less "gotcha".

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PostPosted: Mon Oct 28, 2019 9:27 am 
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You're also placing a lot of blind fail in the hands of those who have the more odd-ball cars, as who's gonna say they're wrong? It would be REAL easy for me to present "documentation" and a stock unmodified 62mm throttle body that would convince anyone that's what my car is supposed to have, when no one else actually knows what my car is supposed to have. Too bad for me though that in reality, enough people know it's supposed to be 58mm. :lol:

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PostPosted: Mon Oct 28, 2019 10:29 am 
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Nissan 240SX had multiple TB sizes for the same engine based on trim (auto has a larger TB than manual) and year of production even though they are all "same engine".
91-94 chassis were S13 chassis with DOHC engine KA24DE. different ECU, throttle body, and cams. other little changes as well.
95 was the S14 chassis using the OBD-I engine same as the 1994 S13 chassis, but it has a little different setup since it was the middle of a mishmosh of update to the OBD-II setup from the 96-98 chassis.
96-98 chassis had the OBD-II version of same engine, which had revised ECU, cams, and throttle body to reduce emissions and moved the torque curve down. (I'll ignore the multiple cams since they are allowed to be replaced with max lift )

In the 240SX spec line, there's only 2 lines for all that mess:
S13 chassis- SOHC in full prep
OR
S13/ S14 chassis DOHC in limited prep. That single DOHC spec line covers an 8 year production span and half a dozen variations of intake, throttle body, ECU, etc.

Now exactly which size came on which model? yeah, someone knows that stuff somewhere, but not me.

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PostPosted: Mon Oct 28, 2019 12:21 pm 
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Kevin, you have just solved the whole Prod Old car problem. Since the current crop of old car owners are in fact old, they won't be photoshopping the documents needed to prove their TB sizes are legit. So they will have to work with a whole younger generation to create the fake documentation. Thus mentoring a whole new group of young racers into Prod. Brilliant. :ask: :lol:

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PostPosted: Mon Oct 28, 2019 12:24 pm 
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Matt93SE wrote:
Nissan 240SX had multiple TB sizes for the same engine based on trim (auto has a larger TB than manual) and year of production even though they are all "same engine".
91-94 chassis were S13 chassis with DOHC engine KA24DE. different ECU, throttle body, and cams. other little changes as well.
95 was the S14 chassis using the OBD-I engine same as the 1994 S13 chassis, but it has a little different setup since it was the middle of a mishmosh of update to the OBD-II setup from the 96-98 chassis.
96-98 chassis had the OBD-II version of same engine, which had revised ECU, cams, and throttle body to reduce emissions and moved the torque curve down. (I'll ignore the multiple cams since they are allowed to be replaced with max lift )

In the 240SX spec line, there's only 2 lines for all that mess:
S13 chassis- SOHC in full prep
OR
S13/ S14 chassis DOHC in limited prep. That single DOHC spec line covers an 8 year production span and half a dozen variations of intake, throttle body, ECU, etc.

Now exactly which size came on which model? yeah, someone knows that stuff somewhere, but not me.



Well the 240 is a scary RWD Nissan product so there is no way even with a 75mm TB it could get enough tire under the fenders to not burn them up in a race at the weight it is required to run. LOL. We'll give them a pass.

Makes me glad I race a Honda product.

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PostPosted: Mon Oct 28, 2019 12:29 pm 
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Brett W wrote:
Kevin, you have just solved the whole Prod Old car problem. Since the current crop of old car owners are in fact old, they won't be photoshopping the documents needed to prove their TB sizes are legit. So they will have to work with a whole younger generation to create the fake documentation. Thus mentoring a whole new group of young racers into Prod. Brilliant. :ask: :lol:


scanned microfiche docs are SOOO easy to forge... the quality is so bad on them, nobody can read the numbers anyway! just print it out, use a typewriter to correct any text you want, scan them, FAX them to yourself, print it, scan it again in black & white, then reinsert it back into the manual... by that point, the image quality will be so bad it looks like an original manual!!


Attachments:
trans.JPG
trans.JPG [ 121.08 KiB | Viewed 2142 times ]

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PostPosted: Mon Oct 28, 2019 12:47 pm 
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Brett W wrote:
Well the 240 is a scary RWD Nissan product so there is no way even with a 75mm TB it could get enough tire under the fenders to not burn them up in a race at the weight it is required to run. LOL. We'll give them a pass.

Makes me glad I race a Honda product.

My STU car is 2680lbs. (and I weigh ~240). Still has factory glass and bodywork, w/ cheap aftermarket steel hood that weighs 60lb easily. so one could easily get the car under 2600lb. I run 245/40/17 DOTrs on it and the tires are happy even at the end of the race.

Prod rules make it weigh 2600 with stock trans, and you could run the 245 Hoosiers on it without a problem. (BTW there is room to fit 305+ tires under the car with allowed fender flares.)
However, even at the 2600lbs, the factory intake manifold and TB limits that engine to about 210whp so without that 75mm TB, it's not going anywhere fast.

It's not a bad car at all, but there's no way it can keep up with a front running EP car at the current rules. at that weight, the car needs another 50hp to be close.

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