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Team NRG
04-21-2004, 11:49 AM
There is alot of speculation that some of the fellow ITS competitors are now running the new Renesis RX-8 rotors in their 13B RX-7 engines. This would cause much greater compresion . Does anyone know more on this. Lets just say that some RX-7's are now 4-5 seconds per lap quicker than they were last year.

Greg Amy
04-21-2004, 01:08 PM
Of course it would be cheating; how can there be any question to the matter?

However, to conclude someone is cheating simply because they've gotten faster is an invalid argument. If you've got proof (or even strong suspicion) that someone you know is using the wrong rotors, then by all means toss some paper at them. But if your only "proof" is an increase in performance then I suggest you not try to rouse the rabble...

Banzai240
04-21-2004, 01:13 PM
Originally posted by Team NRG:
There is alot of speculation that some of the fellow ITS competitors are now running the new Renesis RX-8 rotors in their 13B RX-7 engines. This would cause much greater compresion . Does anyone know more on this. Lets just say that some RX-7's are now 4-5 seconds per lap quicker than they were last year.

I don't think there is much question that this would be entirely illegal... Even if you consider the rotor a piston, it must an exact equivalent of the original piece, so again, the Renisis rotors certainly would not fit this rule...

There's one way to find out if the rumors are true...



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Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX
http://home.comcast.net/~djjordan/Web/DJ_AV1.jpg

lateapex911
04-21-2004, 01:22 PM
It is my understanding that a Renesis rotor breathes differently, due to the shape in certain areas, and it's performance characteristics are not due to compression alone.

These shape items can be applied to stock rotors as well.

Both are, at this point, clearly illegal and flagrant cheats. Easy protest to win, and even if it IS a Renesis rotor, you don't need to prove the source, just the mods.

But, lets think for a second about 4-5 seconds per lap. What does that represent horsepower wise?? It's a HUGE number.

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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

ITSRX7
04-21-2004, 01:26 PM
Get some more facts and write the papers. The only way to control this kind of thing is to nab one.

There is nothing more entertaining than tearing down a motor, determining it's illegal and then walking away with it in pieces.

Conversly, there is nothing better than having your motor torn down, having it found legal and then knowing that people who claim you are cheating pay for your rebuild.

AB

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Andy Bettencourt
06 ITS RX-7
FlatOut Motorsports
New England Region
www.flatout-motorsports.com (http://www.flatout-motorsports.com)

ITSRX7
04-21-2004, 01:35 PM
Originally posted by lateapex911:

But, lets think for a second about 4-5 seconds per lap. What does that represent horsepower wise?? It's a HUGE number.



The new motor puts out 238hp. If you assume the same 25% increase that the 89-91 13B gets in IT form, you are looking at 295+ crank hp - over 240 at the wheels.

I would think these cars would be shattering long-course track records with that kind of power. I am betting it's more driver training and car 'prep' than it is a Renesis.

Someone like SpeedSource who has development time with both engines may be able to teach you a few things about spotting the differences without opening up the whole unit.

AB

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Andy Bettencourt
06 ITS RX-7
FlatOut Motorsports
New England Region
www.flatout-motorsports.com (http://www.flatout-motorsports.com)

04-21-2004, 02:16 PM
Jake, your right and another thing that my engine builder told me while we were discussing which parts to use in my EP engine and I believe paul yaw said the same thing, that raising the compression alone in a rotary will make less power not more, it requires a completely different intake configuration to gain any hp from comp ratios. the 700 HP GTP Mazdas of the past that spun 16000 rpm had less than 10:1 if I remember correctly. I have been told that the rx8 rotors are lighter than the 7's and that the side seals are better which is why the EP guys are experimenting with them right now. but without forced induction (turbo) or high velocity intake ports I dont think they would be much of an advantage other than gaining rpm's a little quicker.

Daryl

lateapex911
04-21-2004, 03:41 PM
Originally posted by ITSRX7:
The new motor puts out 238hp. If you assume the same 25% increase that the 89-91 13B gets in IT form, you are looking at 295+ crank hp - over 240 at the wheels.

AB



Andy, we're probably on the same page. The rotor doesn't, from what I understand, produce the numbers by itself. It is part of the Renesis package, and that package doesn't get transfered with just a rotor swap. My understanding was the side chamfers affect the timing and the breathing, and can account for a 5 - 8 hp gain in an ITS engine. Of course, stock rotors, as you well know, can be chamfered as well.

It is detectable without a complete tear down.

But 5-8 hp is NOT going to represent 4-5 seconds a lap at even the longer tracks.



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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

Karl Bocchieri
04-22-2004, 09:01 PM
Gee, 240Hp sounds familiar. Oh, right about what a well preped E36 makes.

I just bought new Hoosers on new lightweight wheels. The last seasons I ran on 2 year old tires, I might actually be 3-4 seconds faster this year. Please someone protest my engine, it's 6 seasons old and needs a rebuild anyway, and I need your help paying for it.

Banzai240
04-23-2004, 12:06 AM
Originally posted by lateapex911:
Of course, stock rotors, as you well know, can be chamfered as well.

It is detectable without a complete tear down.

I disagree... I could easily detect it by simply removing the intake and using the appropriate fibre optic scope, or even with perhaps the correct mirror and light... The chamfer would have to pass over the port at some point, and would be easily seen...



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Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX
http://home.comcast.net/~djjordan/Web/DJ_AV1.jpg

lateapex911
04-23-2004, 01:25 AM
Hey Darin, isn't that what I said? It is detectable, with no tear down...
I must be confused....

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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

Banzai240
04-23-2004, 02:17 AM
Originally posted by lateapex911:
Hey Darin, isn't that what I said? It is detectable, with no tear down...
I must be confused....



Sorry... It was late and I misread what you wrote... Feel free to be un-confused! http://Forum.ImprovedTouring.com/it/wink.gif



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Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX
http://home.comcast.net/~djjordan/Web/DJ_AV1.jpg

Bill Miller
04-24-2004, 09:59 AM
I'm w/ Jake, I can't see just rotors making that kind of difference in lap time, if the car was running anywhere close to competitive lap times to start. To cut 4-5 seconds off of even a 2:00 lap takes a lot, if the car was even close to being developed and the driver was even close to being competent. I'd be willing to be that those 4-5 seconds would translate to 30-50 hp increase. Can't see that from just rotors, especially w/o any port work.

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