Resistance & loss of performance (seemingly)

[Electro]

Maybe I'm just getting too used to the feeling of how fast my nsx takes off, but lately it feels like i've been losing power... I just had a major service/upgrade - timing belt & water pump, changed all belts, 90k service, Dali Clutch & lightened flywheel, and short gears...

when pressing on the gas it just feels very heavy... i had the nsx tech adjust the accelerator pedal cable, he told me there should be 12mm of slack in the cable (dont know any validity to that)... and it just seems to take off sluggishly. I was haulin ass down the highway when a new C5 Vette came up behind me... we ran for a bit but he was slowly pulling on me thru all gears.. Now i figured I would have been pulling on HIM since i have the short gears installed. The Vette certainly sounded stock, but i could be mistaken. Nevertheless, it still kind of confirmed my worries...

maybe i'm just halucinating.. i dont know! Its driving me crazy though... it almost feels like the parking brake is on...but i know thats not the case....

anyone have any ideas??

-Electro

[This message has been edited by Electro (edited 05 June 2001).]

 

[nsxtasy]

A C5 Corvette should have slightly better acceleration than a 3.0-liter NSX, stock to stock, all other things being equal.

The primary benefit of the short gears is slightly better acceleration in the 40-60 mph range. Above that, they don't really do anything. (They benefit at certain speed ranges, but detract at others.) So the short gears shouldn't make much difference on the highway, as opposed to a stoplight.

You might want to consider hooking up with another NSX owner in your area to swap each other's cars for a quick test, to see if yours is performing the way it should.

 

[johndoh]

Clogged fuel injectors?
Air filter?
It could be a mental thing... There are some days when my NSX does feels quicker. I don't think checking against a C5 was a good test. As stated above, you should check with a fellow NSX in your area and see if there really are any differences w/ your performance.

[This message has been edited by johndoh (edited 05 June 2001).]

 

[ilya]

I have noticed degradation in performance after driving the car in traffic for a couple weeks. After every event, once having driven the car hard for 200 miles, it feels much better again for a short while.... until another week of traffic.

Don't know if it's mechanical or the ECU adjusting.

 

[nsxtasy]

I have noticed degradation in performance after driving the car in traffic for a couple weeks. After every event, once having driven the car hard for 200 miles, it feels much better again for a short while.... until another week of traffic.

Don't know if it's mechanical or the ECU adjusting

In those circumstances, it could be the driver's attitude that's adjusting...

 

[ilya]

bastard.

Maybe I can buy a cursing horn to give my finger a rest before I sprain it.

 

[sjs]

Mine feels that way sometimes, but I have a fool-proof way to fix it. I drive my 1982 Scirocco for a few days.

More seriously, that's one of the reasons I bought the G-Cube and Geez software. Record some base-line runs then compare to new runs whenever you make changes or things feel different.
http://extremegeez.com/GCubex.html


[This message has been edited by sjs (edited 05 June 2001).]

 

[dswartz]

Never go by seat of the pants feel. Take it to the drag strip, time slips don't lie. Or, take it to the dyno.

I've seen so many people mistake loud for fast. "I put on a new intake, and boy is my car fast now". Or, just because another car beats them they think something is wrong with their car.

Dyno results and drag strip time slips don't have emotions, they just tell it like it is.

 

[sjs]

Never go by seat of the pants feel.

Agreed.

Dyno results and drag strip time slips don't have emotions, they just tell it like it is.

But they don't really tell the whole truth and nothing but the truth.

Drag slips give you only the end result, not how hard it pulls in each gear or whether the driver shifted the same etc. A dyno doesn't reflect changes in aerodynamics, rolling resistance (wider tires), added wieght (you or the car), or the effect of airflow through and around the engine compartment to name a few.

An accellerometer measuring G forces is your best bet for this type of analysis. You don't even need a hard launch or a speed shift to see how hard it hard pulls through the the rev range in each gear. Not to mention, you can use it any time you want, as often as you want.



[This message has been edited by sjs (edited 05 June 2001).]