New SCCA IT Class -- ITR
04-10-2006, 06:17 PM
#16
Race Director
Originally Posted by tchandler
George
Just an FYI,
I have a 99 boxster that makes 248hp/ 220rwhp with a Supercharger/headers/giac chip. NO way a normal aspirated boxster will make 250. Numbers were taken on a Dynojet 250 back in 2001 when I put it on.
Not that I race the boxster anyway, just thought you should know.
Just an FYI,
I have a 99 boxster that makes 248hp/ 220rwhp with a Supercharger/headers/giac chip. NO way a normal aspirated boxster will make 250. Numbers were taken on a Dynojet 250 back in 2001 when I put it on.
Not that I race the boxster anyway, just thought you should know.
1) Have you had your engine on a engine dyno as well as the car on a chassis dyno? I'm just curious how you know both numbers.
2) Why won't a Boxster engine make a 25% gain? It's amazing how many cars do. And please don't tell me that Porsche optimized that engine from the factory. I don't buy it. The E36 BMW (a car that is 10 years older) can get gains of 30% from the same size engine and it was rated within 12 hp from the factory.
I'm not trying to be argumentative, but in order for me, the ITAC, and the CRB to take statements at facts, they must be backed up.
04-10-2006, 06:28 PM
#17
Rennlist Member
Jeff,
An interesting idea and as usual new ideas always generate more negative at first. To me that means that they need to be re-fermented with consideration to what is said.
Here is my .02. I would challenge the wheel hp you mention for any of Porsches you listed and suggest that the group look again at the hp/wt numbers they propose. I have a 944S2 that is prepared as a PCA F class or NASA 44SC. The factory hp was 208 (that is not wheel hp) and I wonder how any 944 S2 can get to 210 wheel hp without super/turbo charging.
An interesting idea and as usual new ideas always generate more negative at first. To me that means that they need to be re-fermented with consideration to what is said.
Here is my .02. I would challenge the wheel hp you mention for any of Porsches you listed and suggest that the group look again at the hp/wt numbers they propose. I have a 944S2 that is prepared as a PCA F class or NASA 44SC. The factory hp was 208 (that is not wheel hp) and I wonder how any 944 S2 can get to 210 wheel hp without super/turbo charging.
04-10-2006, 07:10 PM
#18
Race Director
An S2 should be able to put down about 195-200 or so based upon my estimate. My basis is the fact that Jon Milledge is getting about 15% additional hp for the 944S.
I'm not sure what the factory did differently between the S and the S2 so it's a bit tougher for me to estimate the hp increase. An S2 should be able to easily put down 210 whp w/o boost. Just perhaps not in IT trim.
I'm not sure what the factory did differently between the S and the S2 so it's a bit tougher for me to estimate the hp increase. An S2 should be able to easily put down 210 whp w/o boost. Just perhaps not in IT trim.
04-10-2006, 07:27 PM
#19
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Nader, thanks for the note and for the interest. We appreciate the thought and really hope to have Porsche more involved in ITR than it has been historically in ITS.
Per George's note, if you add 15% to the stock crank hp you get 238 crank hp.
This is a bit on the low side for ITR, but simply means that the car has to weigh around 2800 to get to the target hp/weight ratio.
Per George's note, if you add 15% to the stock crank hp you get 238 crank hp.
This is a bit on the low side for ITR, but simply means that the car has to weigh around 2800 to get to the target hp/weight ratio.
04-10-2006, 11:08 PM
#20
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So what is wrong with my original proposal of a 986S? 250 hp box(ster) stock and weighs just south of #3000. My 2000S with cf hood, Sparco seats on manual sliders, Momo steering wheel with quick release, ,no muffler and a full cage weighs 3000# exactly with the toolkit, spare tire, Porsche PCM, full leather and carpets, 3/4 tank of gas and AC. Change out the battery, lose the carpeting/PCM/speakers/power windows/AC and you are down to 2900# ready to race.
Bro
Bro
04-11-2006, 12:20 AM
#22
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Originally Posted by JeffYoung
250 stock crank hp is higher than the class target (230 crank hp max, with two exceptions, the 968 and the S2000 for reasons I will discuss with you if you want).
Bro
04-11-2006, 12:23 AM
#23
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He's talking about crank hp after allowed IT mods, which consist of:
1. Remove all emissions crap.
2. Free header and exhaust.
3. Any chip/ECU that will fit in the stock box, meaning Motec.
4. .5 compression bump.
5. Port matching of the intake/head/exhaust ports.
6. Balancing of the rotating assemblies.
It is expected that most motors gain about 20-25% in "IT" trim, although it is also accepted that Porsches are usually less due to the fact that the are optimized from the factory. A 2.5 or 2.7 944 motor will not see that kind of increase, or if it will, it will be after big dollars are spent.
1. Remove all emissions crap.
2. Free header and exhaust.
3. Any chip/ECU that will fit in the stock box, meaning Motec.
4. .5 compression bump.
5. Port matching of the intake/head/exhaust ports.
6. Balancing of the rotating assemblies.
It is expected that most motors gain about 20-25% in "IT" trim, although it is also accepted that Porsches are usually less due to the fact that the are optimized from the factory. A 2.5 or 2.7 944 motor will not see that kind of increase, or if it will, it will be after big dollars are spent.
04-11-2006, 07:26 AM
#24
Race Director
In the case of the 944 there is a very specific reason it won't see more than a 17% increase - the cam is the limiting factor. It's not a case of factory optimization and in fact it's quite the opposite - a factory limitation.
The rest is correct.
The rest is correct.
