Curious about KA24DE classing.

[turboICE]

It has always surprised me that the DE was up classed entirely.

I guess my view on the OEM 15HP difference even if widened to a 20HP difference in IT full build is that the full class up wasn't justified.

One explanation given to me was that at the time of classing DOHC was considered so high tech that it just had to be ITS. No idea if it was any basis or not.

I have been told that DOHC or not the throttle body housing is restrictive to ever experiencing the full benefits of the DE head. As well I have heard that there aren't any known S14's that can make ITS weight.

I am just curious with all the process activity why those running the DE in ITS wouldn't have asked for an ITA classing with a weight some X pounds over the E motor? Too heavy? Want to run the S chasis in ITS against the Mazdas and Bimmers anyway?

Just hypothetically what would the wieght of a KA24DE 240SX be under the new process if it was ITA instead?

[zracre]

Putting that car in ITA would take all the 12 valve cars down a notch...the car runs decent (its no front runner) in ITS...Chris Newberry did a good job with one...with a few adjustments in weight it should be a good car for ITS. I think all the 4 cyl cars in ITS need alittle help. The carbed rotarys seem to have a problem making torque (hp is good) to be competitive in ITA but fuel injection obviosly helps (huge brakes and better suspension too). Same deal with GSR vs non GSR with hondas...GSR makes lots of power but same torque as non GSR so lap times are close... another two pennies

[Joe Harlan]

Ed I do agree the car is to much for ITA but I also agree that most folks are struggling to get them to ITS weight..(S/14) I would think that a move to ITA could and should be considered with an SIR to cap them to HP numbers that would fit the class. That may sound a little funny but I have raced an S14 at 2900 lbs and would not do it again. I built the engine in Darins car and I believe I could still squeeze a little more out of it which would take it above ITA but it would not be enough to have a shot at the front of S. This is why I would go for the SIR I think if the HP were limited to the 12 valve it would be a good ITS car.

[erlrich]

It has always surprised me that the DE was up classed entirely.

I guess my view on the OEM 15HP difference even if widened to a 20HP difference in IT full build is that the full class up wasn't justified.[/b]

Just guessing Ed, but I would think that the E motor is probably right at the ceiling for HP in ITA, and therefore anything above that would automatically get bumped to S.

Just hypothetically what would the wieght of a KA24DE 240SX be under the new process if it was ITA instead?
[/b]

Again just a guess, but I would bet you'd be looking at a car in the 2,800 - 2,900 lb. range. As Joe mentioned, I'm not sure the car would handle or stop very well at that weight. I think the car would be in the same situation in ITA as the Bimmer is in ITS, and would have to get the same treatment.

Of course, 2,900 lbs. would be nice if you ever needed to move a 2,200 lb. Miata or CRX out of the way

[turboICE]

Joe, I hoped to hear from you on the topic, since even working/fielding these cars you approach their treatment in class and rules in an almost objective disinterested fashion.

I assume you mean good ITA car in the last sentence.

Wow, that was a response that I definitely wouldn't have expected.

So the IT potential power is enough that the weight would be quite a lot in ITA targets? 2900 lbs?

Skip any other reason that could have been given, it is justifiably outside the ITA window if that would be the resultant weight.

Extremely interesting that you would (completely hypothetically of course) consider the possible shift to ITA with an SIR for a car that can not realistically get to the front of ITS because it can't legally make competitive weigth for its HP potential, no matter how low they make the weight it in ITS.

You didn't respond in the thread on helping cars legally make their new process weights. I guess without disagreeing that what you mention is a valid method to address the car's classification, I would think providing more legal ways to reduce weight (lexan) in ITS would be easier to move on (given the explosive response to SIR technology) than a move to ITA with SIR.

Of course, 2,900 lbs. would be nice if you ever needed to move a 2,200 lb. Miata or CRX out of the way
[/b]

And given the sturdiness of the rear bumper would make an excellent brake for me when I go too deep!

Again just a guess, but I would bet you'd be looking at a car in the 2,800 - 2,900 lb. range. As Joe mentioned, I'm not sure the car would handle or stop very well at that weight. I think the car would be in the same situation in ITA as the Bimmer is in ITS, and would have to get the same treatment.[/b]

Probably makes for one excellent example of when else an SIR might be warranted. If ITS 240SX participants were to ask for classing in ITA with an SIR limiting to KA24E potential and resulting warranted weight - it sure would make their whining look rather petty!

Out of curiousity Joe where would you put an SIR in the intake?

[Joe Harlan]

Joe, I hoped to hear from you on the topic, since even working/fielding these cars you approach their treatment in class and rules in an almost objective disinterested fashion.

I assume you mean good ITA car in the last sentence.

Wow, that was a response that I definitely wouldn't have expected.

So the IT potential power is enough that the weight would be quite a lot in ITA targets? 2900 lbs?

Skip any other reason that could have been given, it is justifiably outside the ITA window if that would be the resultant weight.

Extremely interesting that you would (completely hypothetically of course) consider the possible shift to ITA with an SIR for a car that can not realistically get to the front of ITS because it can't legally make competitive weigth for its HP potential, no matter how low they make the weight it in ITS.

You didn't respond in the thread on helping cars legally make their new process weights. I guess without disagreeing that what you mention is a valid method to address the car's classification, I would think providing more legal ways to reduce weight (lexan) in ITS would be easier to move on (given the explosive response to SIR technology) than a move to ITA with SIR.

And given the sturdiness of the rear bumper would make an excellent brake for me when I go too deep!
Probably makes for one excellent example of when else an SIR might be warranted. If ITS 240SX participants were to ask for classing in ITA with an SIR limiting to KA24E potential and resulting warranted weight - it sure would make their whining look rather petty!

Out of curiousity Joe where would you put an SIR in the intake?
[/b]

I didn't respond to the weight reduction thread because I really don't want see IT turned into prod. I have enough history to understnd that it started out with "i am just gonna put it in for a second" Now they are all preggo.....

As far as the SIR goes I really think that putting out in front of the MAF sensor will be the best place. Lookig at the one raetech desigh I could put that coned end into a Pop Charger type filter. The advantage as I see it would be that the MAF would try to counter the effect of air going sonic which may net one or two more HP at the end. It would also keep the motor from flooding the plugs when it runs out of air. With a little research I think people will get behind this technology but like anything in life nobody wants to give up even the smallest advantage. I like racing. I like building cars and building engines and helping the underdog at the racetrack. I really don't care if it is a bimmer or a yugo as long as it is classed fairly.

[murphyd]

Personally as an owner of a 95 s14 ITS car I don't feel that there has been enough development to the cars to warrant reclassification. I realize that the question in this post was why these cars were classified where they are. Again personally I feel that the car has been classified correctly. My experience, here in the SE at tracks such as VIR, Lowes, CMP, Roebling and Road Atlanta, is that with a developed package, including Driver, that the cars can be competitive. More so at certain places than others but that seems to be true with other cars as well. I believe the jury is still out on this issue. I, like others, would hate to drive this car at 2900lbs!! Let's keep developing them in S at current weight and see what happens. Just my 2 cents!

[Joe Harlan]

Personally as an owner of a 95 s14 ITS car I don't feel that there has been enough development to the cars to warrant reclassification. I realize that the question in this post was why these cars were classified where they are. Again personally I feel that the car has been classified correctly. My experience, here in the SE at tracks such as VIR, Lowes, CMP, Roebling and Road Atlanta, is that with a developed package, including Driver, that the cars can be competitive. More so at certain places than others but that seems to be true with other cars as well. I believe the jury is still out on this issue. I, like others, would hate to drive this car at 2900lbs!! Let's keep developing them in S at current weight and see what happens. Just my 2 cents!
[/b]

David, I am not pushing for a move just stating it this way. I think the package comes up 20HP short if you actually make weight. Now the is 20hp to a 240z or RX7. Having built a few of these engines I am pretty convinced that 20HP will be really hard to find.

[jamsilvia]

At one point I was really on board for the DOHC going to ITA. But thinking about the weight (especially now that the ITA cars got a bump) - I have to agree that the car doesn't belong in ITA as the rules exist now...and definitly not at 2900 lbs. And I do agree that the E is probably very close to the top of the envelope for ITA.

I can only speak from a limited prep point of view (of which there are many) - but my car with similar mods to a FC gets readily spanked (in a straight line....I don't think the FCs handle nearly as well, IMHO). If that can be extrapolated to the top of the prep ladder, then I think the car really is a huge underdog...handling or not. I at least have the advantage of having a S13 chassis - so I can closely make weight (but not quite)...I lose out on the wider track and bigger wheels available tho.

I'm one of the guys that think an appropriately sized restrictor based on your running weight across the IT board might be reasonable.....so I like the idea of the DE in ITA with a SIR.

My $0.02

joe

[turboICE]

I lose out on the wider track and bigger wheels available tho.[/b]

How so?

[stevel]

How so?
[/b]

I'm assuming he meant that because he has the DE in the S13 chassis. I assume the S14 chassis has those bits.

s

[turboICE]

Not sure if the S14 fenders are wider but track can be adjusted to your fender width with spacers or offset and the S13 spec line in ITS can use 16" wheels. So I didn't understand the track and wheel size give up on the S13 in ITS.

[Joe Harlan]

Not sure if the S14 fenders are wider but track can be adjusted to your fender width with spacers or offset and the S13 spec line in ITS can use 16" wheels.
[/b]

The S14 doesn't get the good early cams though.

[murphyd]

What do you mean when you said "similar mods to an FC"? I assume you mean fellow competitor. Not to play devils advocate but similar mods effect differnt cars in different ways. I agree that the cars are down on horsepower to the top cars in class, but again at certain tracks the torque and handling of the 240sx has, at least in my experience, been able to overcome this somewhat. I do feel that this car requires me to be a better driver to compete because of the lack of more HP. I guess this is why NASCARteams have so many different chassis' for the different tracks.

Joe Harlan- How much effect do you think the early model cams have? I have a friend who has a track days s13 91 model with an IT prepped engine and pretty much the same suspension as our s14 and I'm consistently faster in the S14. His hopes are to run ITS in the near future and we do a lot of side by side testing. Weights are close but our car is slightly lighter (150lbs). SO far this is where I have figured most of the difference comes from. Other opinions?

Nice to good discussion of these cars!!

[Joe Harlan]

What do you mean when you said "similar mods to an FC"? I assume you mean fellow competitor. Not to play devils advocate but similar mods effect differnt cars in different ways. I agree that the cars are down on horsepower to the top cars in class, but again at certain tracks the torque and handling of the 240sx has, at least in my experience, been able to overcome this somewhat. I do feel that this car requires me to be a better driver to compete because of the lack of more HP. I guess this is why NASCARteams have so many different chassis' for the different tracks.

Joe Harlan- How much effect do you think the early model cams have? I have a friend who has a track days s13 91 model with an IT prepped engine and pretty much the same suspension as our s14 and I'm consistently faster in the S14. His hopes are to run ITS in the near future and we do a lot of side by side testing. Weights are close but our car is slightly lighter (150lbs). SO far this is where I have figured most of the difference comes from. Other opinions?

Nice to good discussion of these cars!!
[/b]

David, The early cams allow the engine to rev a bit better. The difference in the S13 is it uses the same small MAF sensor as the early S13. The S14 has a late design that allows much better air flow. The S14 is cam limited. I have built a 225HP engine out of stock parts but it would not be IT legal. I gues the point is I am not sure you cn rub hard enough on legal parts to make the required HP to get to the front. I know the car is good on certain tracks but it need to be good on a larger average of tracks.

[jamsilvia]

Not sure if the S14 fenders are wider but track can be adjusted to your fender width with spacers or offset and the S13 spec line in ITS can use 16" wheels. So I didn't understand the track and wheel size give up on the S13 in ITS.
[/b]

The track is wider on the S14 - so yes, I can make the S13's track wider - but doing the same offset change to the S14 would result in still a wider track for that car.

My bad on the wheel thing. The S13's never came with 16" wheels - so I didn't think they'd be allowed to run them...and I didn't open the GCR when I originally posted.

[jamsilvia]

What do you mean when you said "similar mods to an FC"? I assume you mean fellow competitor. Not to play devils advocate but similar mods effect differnt cars in different ways. I agree that the cars are down on horsepower to the top cars in class, but again at certain tracks the torque and handling of the 240sx has, at least in my experience, been able to overcome this somewhat. I do feel that this car requires me to be a better driver to compete because of the lack of more HP. I guess this is why NASCARteams have so many different chassis' for the different tracks.
[/b]

Yes - a fellow competitor. And yes, I agree - the mods DO make power differently on each car. e.g. the FC's have a header/exhaust combination that makes a 28% gain over stock. Supposedly JUST with that header/exhaust change! And the individual I was considering for comparison doesn't have this top of the line job - he has the 2nd or 3rd best option.

For comparison:
my car: JWT ecu, HotShot headers, 3" header-back exhaust, electric fan, 160k motor
his car: header, 3" header back exhaust, elect fan, open filter air intake, 120k roatree

As to the handling-vs-power, driving 240's on track since I first started DEFINITLY made me appreciate proper driving style and keeping speed through the corners (compared to others I know that started out with AWD pitch-and-catch driving styles). And the 240 does seem to corner on par with the Miatas....which does say something about the car considering the weight difference.

In places like Nelson Ledges - the car can hold it's own pretty good, since there's so many long turns - and the track tends to favor handling (and proper shocks!!....holy bumpy!) over power. But at places like VIR full course - the gain through the twisties is offset quite easily by that looooonnnnggg back straight!

joe

[murphyd]

Wow! 225hp! That would be great! I have noticed that the S14 revs quicker and likes to go a little longer before shifting. How much is there to be gained in developing a good header? Tuning the exhaust? How about in the head with a really good valve job and some time on a flow bench? Your opinions of course.

On another topic- I have a helical LSD that I would like to install but it is missing the axle shafts. I know I can purchase these, but have been told that the axles out of a J30 infinity would work. Any experience with these?

[turboICE]

I assume the 225HP stock parts motor (not IT legal) is the S14 MAF and ECU (or AEM), with the S13 DOHC and the SOHC pistons. Which would be the best combination of 240SX parts - highest flow MAF housing, best cam profile and highest CR possible (north of 11:1).

[Andy Bettencourt]

Yes - a fellow competitor. And yes, I agree - the mods DO make power differently on each car. e.g. the FC's have a header/exhaust combination that makes a 28% gain over stock. Supposedly JUST with that header/exhaust change! And the individual I was considering for comparison doesn't have this top of the line job - he has the 2nd or 3rd best option.

For comparison:
my car: JWT ecu, HotShot headers, 3" header-back exhaust, electric fan, 160k motor
his car: header, 3" header back exhaust, elect fan, open filter air intake, 120k roatree

As to the handling-vs-power, driving 240's on track since I first started DEFINITLY made me appreciate proper driving style and keeping speed through the corners (compared to others I know that started out with AWD pitch-and-catch driving styles). And the 240 does seem to corner on par with the Miatas....which does say something about the car considering the weight difference.

In places like Nelson Ledges - the car can hold it's own pretty good, since there's so many long turns - and the track tends to favor handling (and proper shocks!!....holy bumpy!) over power. But at places like VIR full course - the gain through the twisties is offset quite easily by that looooonnnnggg back straight!

joe [/b]

As you probably know, this is a tough comparison. The rules don't allow for any internal mods to the rotory, except for upgraded seals. Common theory can be applied to these - they run fast when loose - almost best when they are about to pop. Just bolting on a good exhaust, open intake and a FPR can get you some nice gains. It's a chainsaw ya know!

I think the ITS S14's are one of the best looking cars in ITS...would love to see one up here in NE with some of the momentum tracks we have. I just love the coupe look of the S13 as well. They are sooo cool. Tristan's car is one of my favs.