Shifting RPM's and driving RPM's

[McAttack]

I tend to drive at low RPM's which is great for gas mileage but there are drawbacks. With a 9PSI CTSC and especially a PowerGrip II clutch, I've found while above 3500 or 4000 RPMs the car runs great but at lower RPM's, it runs a bit sluggish. It "feels" like it is having a negative effect on the car in some way although I don't know why.

The car idles at about 800 RPM. I usually rev to 2k and engage the clutch in first and subsequently shift to the next gear when I hit 3000 RPM in my normal daily driving. Anything above 3000 RPM's and it gets LOUD. If this is the trade off for the added performance that's fine. Also if this is WHY people buy and enjoy their NSX (ie The loud midengine hum, this is great too). I guess I'm just looking for a little confirmation by other owners.

What are your habits as it relates to RPM's and DAILY driving? TIA

 

[AaronR]

All I need is a time and a place! If there is room and the V1 is not lit up I will use as many revs as I can. I love the hear the taitec at high rpm's so I rev it pretty good whenever possible. My take is that these cars were meant to be driven like a sports car, not beaten but driven using the potential. When I want to keep the revs down I'll take out the bmw

Just my take...
Aaron

 

[Number9]

There is some lag with the CTSC kit, not sure if it's latency in the SC bypass response (in transitioning from no-boost to boost) or latency in the RRFPR response, but it definitely is more prominent in a 9-psi CTSC kit on a 3.2L (which has drive-by-wire which may be relevant since most high-boost CTSC experience is on earlier cars) vs. the 6-psi case on a 3.2L. The ESM helped a little, driving at >= 4K RPM helps a lot!

 

[McAttack]

In speaking with Shad at CT, he said the 9psi will exponencialize any nuances you may not even notice on a stock NSX. Kind of like when your a/c is on vs off. I DEFINITELY notice the turbo lag type effect on my '99 3.2

This feedback is good. What I'm hearing so far is that these gremlins just go with my setup. I can deal with this. Just want to make sure others w/similar setups feel the same way. As was said, although it's not meant to be constantly beaten on, it is meant to be driven.

Maybe someone can chime in on this but I kind of think driving at 2000-2500 RPM's and the bogging effect, etc has worse ramifications than driving it at a constant 4-5k. Does that make sense?

 

[bonzo]

I tend to use the entire rev range, but only after I've let it warm up (i.e. 15 - 20 minutes driving). When I first start out, I'll run from 2000 - 4000, in all gears.

Once warmed up, I'll wind it out, usually from 2000 - 6000 in all gears. I rarely wind out to redline, but once in a while...

My reasoning is that the car has such a wide rev range--why not explore it?

 

[sjs]

Been driving a 6lb 3.0 for a bit and notice a distinct lack of throttle response off idle in neutral. I'm guessing it's the relatively restrictive intake at that point. But other than that it doesn't feel at all flat at part throttle low RPM, very close to stock (although it's been awhile since I drove a stock one much).

If yours feels decidedly flat under part throttle low RPM you should probably check the AF under those conditions, just in case the flatness is due to a very rich condition at those times.

 

[Number9]

If it's restrictive just off idle, it wouldn't get better at higher RPM, so that's not likely the culprit.

 

[sjs]

Originally posted by Number9:
If it's restrictive just off idle, it wouldn't get better at higher RPM, so that's not likely the culprit.

I disagree. Keep in mind that I'm speaking about a quick blip in neutral or with the clutch in from idle. At that point the SC is just in the way and the factory optimized intake design has been further compromised by shortening of the manifold. Once you start generating boost and pushing the air in it’s a different story, so at higher RPM it will get better. But as I also mentioned, I don't believe that is his problem anyway. I was simply mentioning a recent observation.

 

[Number9]

Might not the symptom you observed just be the parasitic power lossage from having to turn the twin screws? The idle speed isn't changed from stock (at least mine doesn't appear to be), but you are still turning the SC, albeit in bypass mode.

 

[sjs]

Sure, that might be. But mine also has almost a pause, not quite a stumble, if I blip the throttle sharply. It is very much like having carbs with a bad accelerator pump or just the opposite where too much fuel is pulsed at that first instant. (both have similar feel) My initial impression was just that it is slow to pull in the first gulp of air as the throttle snaps open, but that may not be it. I'll have it on a wideband AF soon so maybe I'll find out.

 

[BadCarma]

Originally posted by sjs:
Sure, that might be. But mine also has almost a pause, not quite a stumble, if I blip the throttle sharply. It is very much like having carbs with a bad accelerator pump or just the opposite where too much fuel is pulsed at that first instant. (both have similar feel) My initial impression was just that it is slow to pull in the first gulp of air as the throttle snaps open, but that may not be it. I'll have it on a wideband AF soon so maybe I'll find out.

Steve, are you installing a permanent w/b 02 sensor and qauge in your ride, or just putting it on a dyno.if its in car.could you post the specifics?
david

 

[McAttack]

SJS and Number 9,

Thanks for your posts. The feel is what SJS described, a slight bog before accel. As mentioned in another of my posts, I was in the speed lane on the highway in traffic and came to a stop. Attempting to switch lanes slightly rolling in first, the car bogged before it "over"throttled. Almost got me hit in the middle lane due to the momentary hesitation and almost made me overshoot to the far right lane when it kicked in. This is the only instnace I had (or could ever think of) where it went from annoying to scary. Figures it would happen!

You mentioned a wide band O2 sensor. While I do have the CT ESM which Shad told me was slightly adjustable, Are there other more stable options out there? For scale, I WILL live with this vs go to the more reliable 6lb setup. It's annoying but not so much that I'd give up the extra HP or torque.....

 

[Wadasan]

Originally posted by AaronR:
All I need is a time and a place! If there is room and the V1 is not lit up I will use as many revs as I can. I love the hear the taitec at high rpm's so I rev it pretty good whenever possible. My take is that these cars were meant to be driven like a sports car, not beaten but driven using the potential. When I want to keep the revs down I'll take out the bmw

Just my take...
Aaron

 

[sjs]

I ordered the EgorPro (dumb name, great product [I hope]). It accommodates dual widebands plus data logging throughput for all the typical OEM and add on sensors. It also has push-button recalibration and offers exhaust back pressure correction if needed (EBP sensors required), just two of the things that separate them from most or all the competition. Another great feature is that it has outputs to mimic the OEM sensors you can install the widebands in place of the originals and serve dual purpose. I won’t do that because turbos have so much back pressure and then I need to add those sensors somewhere anyway, but it sounds like a great feature for SC cars. I won’t have first-hand info for at least a month due to a long back-order line.

 

[McAttack]

Originally posted by sjs:
I ordered the EgorPro ...... it sounds like a great feature for SC cars. I won’t have first-hand info for at least a month due to a long back-order line.

Please keep me posted on this if you don't mind. Chances are I won't look into this until the Spring anyway at this point.

Thanks