Cowl shake on NSX-T

[George Grigoriev]

I continue to have very bad cowl shake on my 05. I have installed the R chassis reinforcement bars and don't see much improvement. Any suggestions what to do next?
Obviously, the shake is apparent with the top off, but at one time I saw a reinforcement bar that mounted directly in front of the windshield wiper motor. I have looked to the link to one of these bars, but no luck.

 

[docjohn]

I live with it.I also have r bars and a rear harness bar that helps tie the car together,and with the type R susp I probably have more shake than you do:wink: BTW did'nt you ask this ? a while ago http://www.nsxprime.com/forums/showthread.php?t=95147&highlight=cowl+shake

 

[pgilliam1]

Sorry I can't answer your question, but it raises a question I've been pondering and anyone responding to this thread would likely know the answer to.
I have a coupe and was thinking about getting a T. I have had turbo Supras and removing the top made the cowl shake so bad I wouldn't enjoy driving the car. Is this cowl shake noticeable in the NSX with the top off?
Sorry, maybe I should have started a new thread :redface:?

 

[USA1]

I continue to have very bad cowl shake on my 05. I have installed the R chassis reinforcement bars and don't see much improvement. Any suggestions what to do next?
Obviously, the shake is apparent with the top off, but at one time I saw a reinforcement bar that mounted directly in front of the windshield wiper motor. I have looked to the link to one of these bars, but no luck.

Hello.
You can reduce the CS with the R Swaybar/Chassis Reinforcement bars but you can't completely get rid of it, what you may do is try to use the clutch and gas pedals to stop this infamous CS. Just give a little gas before you release the clutch and it'll work fine :biggrin:.

 

[Texas91Brent]

STMPO makes an upgrade to the oem braces both up front, and the triangle brace in the rear....I bought a set which has not been sent as of yet....but when installed i will post info on the mod....I hope it tightens up the frame a bit...:biggrin: Do a search in the vendor section

 

[tosugrad]

Is this cowl shake noticeable in the NSX with the top off?

Yes

 

[03 raw nsx]

just weld the doors and leave the top off:biggrin:

Once you remove / don't have a top...the only part attaching the front and rear of you car is the floor. The amount of cowl shake is minor compared to most cars designed in the same era. Try riding in a 91 vette :biggrin: you can use the visor to make your martinis

 

[02#154]

Serious question: can anyone explain how chassis stiffening bars that tie the front frame rails together (NSX-R chassis bars) ahead of the front wheels can address a problem created by the lack of a fixed roof? It seems to me that it can't.

I imagine a pair of 12' long 2x4 planks spanning a 10' gap, with a foot of the plank extending 1' past each edge of the gap. There will be some flex in those planks across the gap, obviously. I don't see how tying together the 1' that's not spanning the gap can help increase the rigidity of the span.

Anyone here care to enlighten me?

J

 

[Ski_Banker]

Sorry I can't answer your question, but it raises a question I've been pondering and anyone responding to this thread would likely know the answer to.
I have a coupe and was thinking about getting a T. I have had turbo Supras and removing the top made the cowl shake so bad I wouldn't enjoy driving the car. Is this cowl shake noticeable in the NSX with the top off?
Sorry, maybe I should have started a new thread :redface:?

I have the NSX-R chassis bars and they definitely help a lot, but it still doesn't get rid of the problem. Importantly -- you don't notice the cowl shake at all when the top is attached, so the problem can be 99% alleviated by keeping the top on. When you take it off, it's just a judgement call. How irritating the shake is just depends on how sensitive you are to the problem, and also how bumpy your roads are. If you have a lot of very cracked roads, you'll notice it constantly. If you have fairly smooth roads, you'll only notice it when driving over RR tracks or hitting potholes.

 

[tosugrad]

I have the NSX-R chassis bars and they definitely help a lot, but it still doesn't get rid of the problem. Importantly -- you don't notice the cowl shake at all when the top is attached, so the problem can be 99% alleviated by keeping the top on.

+1 on the chassis bars. I still notice the shake with the top on. But thats me.

 

[LJSB]

Serious question: can anyone explain how chassis stiffening bars that tie the front frame rails together (NSX-R chassis bars) ahead of the front wheels can address a problem created by the lack of a fixed roof? It seems to me that it can't.
J

You're right! Give that man a cigar!:biggrin:

 

[pgilliam1]

I would be very dissappointed in a sports car, where chassis stiffness is a must for handling, that shook when it hit a bump. I'll stick with my NSX coupe and get an S2000, that has very little shake even with the top down, for that open air feeling. The T sure does look good though.
Happy Motoring!

 

[LJSB]

I would be very dissappointed in a sports car, where chassis stiffness is a must for handling, that shook when it hit a bump. I'll stick with my NSX coupe and get an S2000, that has very little shake even with the top down, for that open air feeling. The T sure does look good though.
Happy Motoring!

The chassis stiffening bars referred to in this thread were made for a NSX coupe and never offered for the other new models even as a option.
Does that mean that "chassis stiffening is a must for handling' on a coupe as well?

Most people make suspension and chassis changes via sway bars, shocks, coil overs, springs, stiffening bars, and more and have nothing to base their choices on other than looks, "seat of pants" or the consensus of like minded folks who think there is a "trick" or a part that will substitute for them developing driving knowledge or skill.
Most of these suspension changes are made because it makes folks feel good in that it renews the initial vehicle buying experience not that they have purposely improved the telemetry of their car's chassis performance.
They believe they have taken their car to the next level.

The NSX-T is a excellent design.
IMO, if one took the totally stock NSX-T and went religiously to EVERY tack event they could with competent instructors guiding along the way it would take most 4-5 years before they would bring their driving skills to that of the car's capability.

YES you will feel a difference if you change parts on your suspension. You will feel lighter in the wallet and you will likely feel the change in how the energy is managed by your car and assume it is for the best because we all are smarter than the average bear.:biggrin: Hey hey hee Yogi!

 

[pgilliam1]

The chassis stiffening bars referred to in this thread were made for a NSX coupe and never offered for the other new models even as a option.
Does that mean that "chassis stiffening is a must for handling' on a coupe as well?

The NSX-T is a excellent design.
IMO, if one took the totally stock NSX-T and went religiously to EVERY tack event they could with competent instructors guiding along the way it would take most 4-5 years before they would bring their driving skills to that of the car's capability.

Track events require "top-on" driving so the cowl shake wouldn't be that noticeable on the track. Most of my driving is daily, but I still require alot from the car when times and conditions permit. And, Yes, chassis stiffness is what frame designers and engineers strive for. I have been doing track events for over 15 years, with and without instructors, and I still ride with drivers that I'm inspired by - even with lesser cars.

 

[LJSB]

Track events require "top-on" driving so the cowl shake wouldn't be that noticeable on the track. Most of my driving is daily, but I still require alot from the car when times and conditions permit.

My post was more directed at the mods that people make and the questionable improvement they make than at you.

Engineers can make a car's chassis stiff but they design them for the street and in this case they wanted "balance" for those conditions.

When one mods the suspension of this car I have no doubt they can feel what they have done only that they don't realize how they affect the car as a whole.

The energy and forces the car experiences doesn't leave the car, it is transferred. My point is do they know to where they are moving it and what it will do to ? Do they know what components will need monitoring for the wear and stress that they have transferred?

In your regard I meant nothing.

That you require more than a NSX-T with the top out can provide on the street when "conditions permit" shows you are exceptional.

In fact, I can't think of anyone I know who has your track experience, 15 years, that would require more than the NSX-T, sans top, provides on the street regardless of "conditions". That say's something.

 

[Ski_Banker]

My post was more directed at the mods that people make and the questionable improvement they make than at you.

Engineers can make a car's chassis stiff but they design them for the street and in this case they wanted "balance" for those conditions.

When one mods the suspension of this car I have no doubt they can feel what they have done only that they don't realize how they affect the car as a whole.

The energy and forces the car experiences doesn't leave the car, it is transferred. My point is do they know to where they are moving it and what it will do to ? Do they know what components will need monitoring for the wear and stress that they have transferred?

In your regard I meant nothing.

That you require more than a NSX-T with the top out can provide on the street when "conditions permit" shows you are exceptional.

In fact, I can't think of anyone I know who has your track experience, 15 years, that would require more than the NSX-T, sans top, provides on the street regardless of "conditions". That say's something.

I agree with the "true performance" aspect of your post (NSX-T vs. coupe, with or w/o chassis bars), but the main complaint I have with the T, when removed, is the wet noodle feel of the steering wheel going over bumps. The chassis bars may have very little impact on true performance, but they do help alleviate this crappy steering feel of the Targa (removed), and that's enough for me to spend a few hundred bucks. FWIW, that's my only mod.

$.02.

 

[StmpoRaceProducts]

I am happy to announce that STMPO has figured out the solution to this...

please see our customers comments in the venbdor section found here...

http://www.nsxprime.com/forums/showthread.php?t=122980

Regards

 

[Sparkman]

I continue to have very bad cowl shake on my 05. I have installed the R chassis reinforcement bars and don't see much improvement. Any suggestions what to do next?
Obviously, the shake is apparent with the top off, but at one time I saw a reinforcement bar that mounted directly in front of the windshield wiper motor. I have looked to the link to one of these bars, but no luck.

Here is the link to the front chassis bar that mounts in the windshield wiper area.

http://www.nsxprime.com/forums/showthread.php?t=122197

 

[Texas91Brent]

STMPO makes an upgrade to the oem braces both up front, and the triangle brace in the rear....I bought a set which has not been sent as of yet....but when installed i will post info on the mod....I hope it tightens up the frame a bit...:biggrin: Do a search in the vendor section

OK I installed rear brace and it is like night and day difference......I still need to install the front brace.....these things are very strong, but lightweight, must be the chromemoly construction. The fit is very tight....that may also be why they work so well, no adjustments or slack.....I am very impressed:biggrin:

 

[Texas91Brent]

I think with the front and rear STMPO braces, I could track my Targa NSX. If you need more, remove your windshield wiper motors and install Ross's/STMPO's front strut bar......I don't need it, without even installing my front brace..yet... but, I love to overkill anything that will make my car tight, and not to mention, a car accident.....Think about it, these cars get in a small accident, and they get totalled, theses STMPO braces could not only save our lives, but let us keep our cars out of the wrecking yards!!!!! Now if Ross could build a very discreet rollbar for the NSX, I think I will be done!!!:wink:

 

[StmpoRaceProducts]

I think with the front and rear STMPO braces, I could track my Targa NSX. If you need more, remove your windshield wiper motors and install Ross's/STMPO's front strut bar......I don't need it, without even installing my front brace..yet... but, I love to overkill anything that will make my car tight, and not to mention, a car accident.....Think about it, these cars get in a small accident, and they get totalled, theses STMPO braces could not only save our lives, but let us keep our cars out of the wrecking yards!!!!! Now if Ross could build a very discreet rollbar for the NSX, I think I will be done!!!:wink:

Thanks for all the possitive feedback Brent.... we are happy to finally get some of our newer more ridgid products on NSX's...

I do have a cage in my race car that was built with .083 chromoly and regulations require .095 wall so were starting over.... it would require drilling into the chassis at the 4 mounting points.... but let me know.

Regards