4.23 w/ FI and 6 spd?

[swerve2007]

I have seen used 4.44 Giken LSD for $1500.00 on prime.

I think the 4.44 giken would be a better setup for the track, but make noise at low speeds.

I went with the 4.23 because I wanted to have all OEM parts, but I don't think it was worth the money. Next time I would just put in the stock 6 speed and a RPS clutch.

sure, you are coming from a completely different approach as your car is FI so you really need just a stronger clutch. for a 6-spd NA car 4.23 is a great match (minus the power steering issue). i guess nobody can really tell what the issue is with mounting the sensor. i guess i will have to figure it out when i do my 4.23 conversion- any welding or milling is no issue.

does anyone REALLY know what the issue is with sensor re-location?

 

[nsxotic911]

I have seen used 4.44 Giken LSD for $1500.00 on prime.

I think the 4.44 giken would be a better setup for the track, but make noise at low speeds.

I went with the 4.23 because I wanted to have all OEM parts, but I don't think it was worth the money. Next time I would just put in the stock 6 speed and a RPS clutch.

You have conflicting statements..Above you wrote: I have Comptech supercharger with 6 speed and 4.23, I love the feel and the acceleration.

 

[Chris NSX]

Don't get me wrong, I love my 6 speed with 4.23 and differential. But if money is a concern it is a very little return for the money. I have NSX-R Input Shaft for 6-spd twin disc clutch conversion, the 4.23 final drive kit and an extra spring plate to increase the preset torque.

6 speed 4.23 final drive kit
Oil Pump Shaft 21173-PR8-J00
Countershaft 23220-PR8-T00
Final Driven Gear 41233-PR8-J00

5 speed differential to a NSX-R spec, thinner differential collar and an extra spring plate for a higher preload.
differential collar 41581-PR8-J00
spring plate 41696-PR8-000

My NSX is a blast to drive, it feels alot faster.

 

[JeffShoots]

I know people that run 4.23 with FI (titaniumdave) and he likes it. Although I respect his opinion, need a 2nd one for such a big decision in life

Dave is running the 6Speed W/OS 4.44 locker on his 2.3L SCed 3L beast.
It's a great combo and on Thill we both shifted more................I Know, I know now you know why his motor went south.............I was driving :redface:

After driving and talking with Shad I'm going with the same combo on my Turbo 3.5L

 

[Larry Bastanza]

does anyone REALLY know what the issue is with sensor re-location?

To give you the short answer: no, not that I am aware of.

I originally had a theory about the location of the sensor and the clearance between the ring gear teeth and the sensor. The 4.23 has a larger diameter then the 4.06, but a smaller diameter then the 4.55. I thought originally when this failure occured, the shim used for the 4.55 was too thick, keeping the sensor too far away from the 4.23. Through imperical testing, my theory is BS.

I have installed many of these in pre-97 power steering cars and had no issue. However the EPS system in the 1997+ cars is a re-design and uses BOTH the vehicle speed sensor and the EPS sensor to operate. This is different from the pre-97 cars. The pre-1997 models also used a system to detect the steering torque applied, and the 1997+ cars eliminated this function.

I have been meaning to ask Honda Japan about this, but have not been able to pursue it. The interesting thing is that you can get an NSX-R with EPS AND it has the 4.23. So, somehow Honda did make this work. With that said, the only short term answer I see would be to back-date the EPS computer, but that would also mean back-dating the steering rack, which is just too cost prohibitive IMO.

Alternatively, I am hopeful the proper NSX-R EPS computer will fix it, but again, to be clear, this is a theory, not fact.

Regards,
LarryB

 

[LJSB]

I have CTSC, 5 speed, short gears and 4.23 r&p.

I like it...a lot.

 

[ownercarry]

WOW, i've never seen so much keyboard wasted on such a simple thing.

gear ratio is about where you RETURN on you shift rather than all these things listed. an exception is track racing where extending your time in a gear to get into a corner could be critical. also, in this case, perhaps, top speed.

ie, you need to go 500 rpm higher into a corner to prevent an upshift (as the time for that woudl clearly slow you down vs. not shifting).

the only way to see this is with your dyno chart.

let's say you're making 200 pound feet of torque starting at 5000 rpm. before that, it's much lower. but after that it does nothing but climb until 7000.

when you shift from 1-2 at 8k, you return at 5k. this puts you in the "beef" of the torque curve. if your torque drops sharply after 7k (and nearly all nsxs do), then you need to shift not long after 7k, even if this means short shifting.

the only exception would be above for a corner.

sorry, but we can't make power without torque since power is a function of torque (torque over time).

since the gears are not evenly spaced, you will need to find the optimal shift "return" point. that's where, when you shift at whatever rpm, you re-engage at the next higher gear.

a torque chart from a dyno will show you this. so you may need to shift at 8k 1-2, 7600 from 2-3, 7500 from 3-4 etc.

the classic example is the corvette c4. the LT1 engine did not like rev. though it had a redline of 5700 rpm, the track guys knew to shift about 4500 because that's where the torque was.

if you don't get it, pm me and be patient, i'll get you some nsd dyno charts and show you.

what i've left out is acceleration over time, which is a tough integral, but nearly always is better for drag racing (because this is about covering a fixed DISTANCE (not time) with a higher numerically higher final drive.

 

[swerve2007]

anywayyyy...



Mr Larry, thanks for the insight- so the location of the sensor is not an issue but actual processing of the signal, right? i personally would be very interested in the information you can get about this issue, i am sure others would be as well.:smile: