Coupe vs Targa

[N Spec]

So, I've been curious about the difference in ultimate handling between a true coupe and topless car. The coupe NSX is ~100 lbs lighter stock and has more rigidity due to it's complete chasis. The targa obviously is heavier and less rigid due to the open top.

I wonder to how much of a degree is changed between the two in terms of ULTIMATE HANDLING. Is the difference that much noticeable in NUMBERS? I say this because, yes, you feel the difference in body twist when you take a hard turn. I've owned a TTop Z and NSX-T as compared to other true coupes I've driven/woned. There is this small clover on-ramp that you would normally take 15-25 mph on around my way. I use that to gauge the handling of the car personally for fun. I never taken it to the extreme, but I've gone 45-55 mph around the curve in all of the cars that I've owned. I've driven a 94 Celica GT(had a sunroof) and 97 Corvette coupe at about the same speed around it as the Z and NSX. The Celica felt more planted and less uneasy compared the Z and N. The Corvette felt more stable too, but to be very honest it felt the same but no better than the Celica (perhaps the interior/ergo and suspension is made it fell that way). The Celica is obviously not as fast or sophisticated as the RWD counterparts. With this said, the Z, NSX, and Corvette would obviously outperform the Celica(340 hp vs. 300hp vs. 270 hp vs. 140 hp), even though the Celica felt more solid when taking the sharp turn.

Okay, now I use another example since the power difference and weight difference were too great in the first example. Let's take for instance the Porsche Carrera GT and the Ferrari 360 Stradale Challenge. The 360SC as I will refer to now weighs ~2800 lbs and makes 425hp. This is very much like the idea of the coupe NSX-R. The CGT weighs ~3000 lbs and makes 450 hp. The 360SC has a close but better lb-hp ratio and it is a true coupe. The CGT is a targa and weighs more. So why is it that the CGT outperforms the 360SC in almost every way. Let's use the famed Nuremberg track.

http://forum.e46fanatics.com/showthread.php?p=3117246

CGT - 7:28
360SC - 7:56

Even both of the Lamborghinis performed better than the 2800lb racebred car. The CGT clocked many times under 8 mins under different conditions. It surprises me to see that Ferrari does not land under 8 mins more unlike the many times Porsche landed under it. Even the 97+ NSX can supposedly do better than the normal 360. Where is the Enzo's numbers for the track? I can't find that anywhere. Ferrari=overated apparently.

Anyways back to my point. They are very similar in numbers and the 360SC actually should have the edge. The CGT performed way better than the coupe 360SC, we are talking a 30 seconds difference! But I am sure the CGT feels less rigid and stable during hard turns even though it's taking the turns the same if not better than the 360SC. So now let's talk about the coupe NSX and the targa NSX again. Besides weight, the 95+ changed it's second gear ratio (slightly more agressive) and LSD to improve performance obviously. The 97+ then changed the transmission completely and made 20 more hp It may have gained a lil bit extra weight due to the bigger brakes and even slightly bigger wheels, but nonetheless, performance was improved significantly.

I been trying to find all of the numbers for the for early NSXs time to late NSX times. It seems to me that the 91-94 NSX perform generally the same as 95-96 NSX on numbers. The Alex Zanardi (although rare and well sought after) performs the same as the regular 97+ on numbers. The only true difference in performance I saw was the NSX-R with the extreme 200lbs difference and of course better suspension/brakes.

It just seems to me that the 100-200 lb difference could almost be nullified to driver error. They say 100 lbs equals about .1 sec of difference in a 1/4 mile, maybe .2 if you are optimistic. The .1 or .2 sec can also be realized in driver error in the shifts. The 360SC vs. the regular 360 times are the roughly same (look them up if you don't believe me) even if though there's a 25 hp and 200 lbs difference. Sometimes you run, 14.1, and sometimes you run 13.8. Even the 200lbs difference of the NSX-R seems ridiculous. They sacrificed the looks of the interior(net mesh? shifter? uglier than stock seats) and some standard luxury(power windows/ac) for instance to acheive the 200 lb difference. I mean every lbs counts, but I am willing to bet the significant difference in performace came from the suspension/brake/aero upgrades and the weight helped a lil bit for acceleration/stopping.

Again, I say don't be fooled by how a car feels sometimes vs. what the car is actually doing. The Twin Turbo Z I had before makes more torque and hp. It also weighed ~400 lbs more. Coming from the Z to the N, the Z felt more powerful due to the torque and the turning/chasis twisting felt the same if not a lil bit more stable since the T-Tops has a cross-member to help stiffen the chassis. But on numbers, they perform practically the same and I willing to bet the NSX might edge the Z out a bit more. I think a lot of people stress that the coupe NSX feels more competent and it is a world of a difference between the two, but the actually reality is that both cars will perform very similar.

I just feel that the forum focuses a lot on weight saving and coupes too much. I realize that the early NSX sold more and are less pricey so I can the see the support. I think the degree of difference between targa vs coupe is too small. It could only truly be realized when they are pushed to the extreme conditions (mods and all) and even then I think the driver's skill can compensate. I just feel that there is a lot bashing on the targas and it seems to me that some feel that they are better than others simple because they start off ~100 lbs less, have more rigidity and payed less for their NSX. Some people like the topless look and appeal. Honda also tried to compensate for the difference with better technology and I think they suceeded. I know everyone has their preference but I think the general consensus of coupe>targa is flawed. Sorry for the long post. Any toughts on this?

 

[02#154]

My take on this is that the coupe is inarguably a better platform for an all-out race car. Just as you've noted, I can also feel the flex of the chassis when the roof is removed. And chassis stability is key in getting the maximum performance from the suspension.

That said, I'd have to say that for the majority of NSX owners the added performance on paper won't always translate into more performance, especially on the street. Out on the track, leaving the top on helps with performance (admittedly, not as much as a closed coupe). The potential performance difference might be a second or two per lap, which is huge to a true race team but practically negligible to a weekend warrior who drives his car on the street most of the time. An average driver likely won't even realize that performance potential anyways. I know that if I were to drive a coupe and a -T back-to-back on a track to the best of my ability there could be a 6 or 7 second window of time that could cover every lap time, and some of the laps in the -T would be faster than some of the laps in the coupe. I'm just not good enough to realize the difference in the cars.

Where the NSX-T gains on the NSX coupe is on the streets. It's just my opinion, but I think there's a huge difference in seeing a coupe drive by and seeing a -T drive by with the top off (the roof off car being more appealing).

If I were shopping for an NSX today, I'd be looking for targas because my driving is mostly on the streets and on the once or twice a year when I make it to a track event, I'd never make use of the only advantage that the coupe offers.

J

 

[soloracer951]

Okay, now I use another example since the power difference and weight difference were too great in the first example. Let's take for instance the Porsche Carrera GT and the Ferrari 360 Stradale Challenge. The 360SC as I will refer to now weighs ~2800 lbs and makes 425hp. This is very much like the idea of the coupe NSX-R. The CGT weighs ~3000 lbs and makes 450 hp. The 360SC has a close but better lb-hp ratio and it is a true coupe. The CGT is a targa and weighs more. So why is it that the CGT outperforms the 360SC in almost every way. Let's use the famed Nuremberg track.

You need to research your cars better. The CGT doesn't make 450 hp. The reason it laps quicker is because it makes 605 HP. You were probably looking the KW instead of HP. Big difference. If you want a car that is more comparable to the CGT you should consider either the Maclaren Mercedes SLR or Enzo.

http://www.youtube.com/watch?v=nlnbNyRgHWQ

 

[Osiris_x11]

covet...

I just feel that the forum focuses a lot on weight saving and coupes too much. I realize that the early NSX sold more and are less pricey so I can the see the support. I think the degree of difference between targa vs coupe is too small. It could only truly be realized when they are pushed to the extreme conditions (mods and all) and even then I think the driver's skill can compensate. I just feel that there is a lot bashing on the targas and it seems to me that some feel that they are better than others simple because they start off ~100 lbs less, have more rigidity and payed less for their NSX. Some people like the topless look and appeal. Honda also tried to compensate for the difference with better technology and I think they suceeded. I know everyone has their preference but I think the general consensus of coupe>targa is flawed. Sorry for the long post. Any toughts on this?

You need to drive both: a NSX coupe and NSX-T, before you can foment such insights.

Body flex is rather noticeable under certain conditions on a NSX-T when compared to a coupe version. That is undeniable. Using other makes/models and generalizing that their prowess and performance would also hold true w/ the NSX isn't worthwhile.

Also, your assertion of there being some so-called bias towards coupes over T-tops is baseless. It all boils down to a matter of preference.

 

[BD]

For bring out the Nurburgring numbers, are you planning on taking the NSX to that track? Or is it going to be a daily driver?

 

[Synthesis]

besides having a lot more hp, the CGT has an all carbon chassis, while the SC is aluminum. i'm sure this comes into play somewhere....

 

[sahtt]

I think you including far too many variables in your analysis.

Traction, rigidity, weight characterstics (centralization, general figure, etc.) and balance are what decides how well a car handles all other things held equal IMO (power, braking capabilities, LSD systems etc.).

Open chassis cars have must have additional reinforcements in the chassis in order to maintain the same level of rigidity of a coupe. Often the same level of rigidity is not even completely acheiveable, but under most conditions it can with enough X braces, etc.

Rigidity and weight distribution choose how traction is maintained and transfered. The more centralized the weight is in the right areas [over the wheels distributing the power, as low as possible, towards the middle of the car as possible] the more force the car can churn out in the form of the car going on its intended path due to the tires maintaining traction. Rigidity is essential in keeping the weight transfers and suspension acitivity in coordination with the highest traction per tire.

Additional weight on the roof of the car is arguably the worst possible position. Even if both cars weighed 3,000lbs, if one had 100lbs more on the roof with a titanium exhaust that saved 100lbs, the untouched car would handle better because less weight would be heaved in the direction of the tire (with gravity as well) by definition under the most force. Now throw in the fact the targa has extra weight AND the extra weight is on the roof. Then combine that with the fact the chassis is not as rigid and any additional chassis flex disrupts how the suspension is supposed to work.

It's not that big of a deal outside of racing, but from a design standpoint a fully closed structure is a must for maximum performance in the standard automobile (not F1 chassis, etc.).

If you ever get a chance to drive a very powerful open chassis car with sticky tires you can feel the chassis flex. One contrary example is the s2000 under most conditions because the factory chassis reinforcements are quite extensive although an x-brace helps.

I prefer the coupe but I'm also semi-obsessed with efficiency by nature. Hmm.. semi-obsessed.. not sure if that's possible.

 

[MvM]

I think Sahtt is absolutely right, you are looking at too many variables.

If you want to compare the NSX Coupe with the NSX-T you should stick to that. It's no use to bring other cars into the equision, it will only complicate things. And if you really want to compare the Ferrari 360 Stradale with something, why not take the 360 Spider instead. Then you have the same comparison as comparing the NSX Coupe with the NSX-T.

As far as differences is concerned, a close friend has a silver NSX-T. He complained about the body-flex, had the Type R chassis bars installed and immediately noticed the difference. More people here on Prime have done the same and AFAIK, ALL commented on the (positive) differences in handling after the chassis bars have been installed.

At the same time, however, it also depends on the tires/wheels, suspension and road-surface your are driving on.

The OEM suspension on the NSX is quite supple and soft compared to other high-performance cars.
I think a relatively soft suspension setup will compensate somewhat for a less rigid chassis. The harder your suspension, the more movement it will transmit to the chassis so the more important it is for the chassis to be stiff and rigid. That same friend has commented to me on several occasion the obvious difference in which his car is taking fast & tight turn compared to my NSX Coupe with TEIN-RA suspension.

Also, if the road surface is smooth and without any serious bumps etc., the differences in the handling between a coupe and targa will be less. The original NSX was heralded in magazines for its handling especially on uneven road surfaces.
I remember one 1991 (Dutch) article between the NSX and the Porsche 911 Carrera wherein performance numbers were more or less equal but it was specifically stated that 'on the bad Italian B-roads in Toscane, it was very hard work in the Carrera to stay with the NSX. The Carrera was constantly jumping left & right whereas the NSX remained stable and true however bad the surface.'

 

[95gsrturbo]

have you considered the difference in engine placement with respect to drive wheels in your equation? as well as the stuff mentioned above.

300Z FR
Corvette FR
NSX MR
Celica FF!!!!!!!!!! pulled you through the corner/curve

have you even been on a track? or properly taught how to push a car through the corner or was this a learn as you go experience. Im not saying you are an inexperienced driver- but technique makes a difference, even on the street.

 

[N Spec]

You need to research your cars better. The CGT doesn't make 450 hp. The reason it laps quicker is because it makes 605 HP. You were probably looking the KW instead of HP. Big difference. If you want a car that is more comparable to the CGT you should consider either the Maclaren Mercedes SLR or Enzo.

Sorry I did jump the gun on that one. I wanted to compare the Enzo to CGT but I couldn't find the numbers for the track so I tried to get the next best thing. I somehow misinterpetted the HP for CGT, as I really did think it made over 500 HP. I remember seeing the Enzo numbers on the track somewhere online, but I couldn't find it again. It was about the same as the Murcielago, if not worse I believe. I remember because I was surprised to see that the Murc was capable of competing since it was like 500 lbs heavier and how some people dog the Lambos about trying to hang with Ferrari. Also, I mentioned the regualr 360 vs the stradale. The 1/4 mile times for the 360 spider and stradale are very close. I don't know what the magazine times were, but from people's times, sometimes they experienced better numbers in the spuder. Perhaps better weight distrution in the rear for traction or lighter weight cause traction lost? I think the best comparison would be the 360 Modena vs 360 Modena spider as it equates NSX-T vs NSX. Then the NSX-R is the Stradale. I couldn't find the track times for the spider though. There was only a difference of 7 seconds for the 200 lb difference/25 hp/etc between the Stradale and regular Modena, which makes me think that 1-2 second driver differences and other conditions make it seem like the two cars are still almost identical given the clear differences in performance upgrades.

I'm not trying to invoke an argument one which car is better. TTops, targa, convert, coupe, or etc is betta! No. I personally like the coupe look of targa vs. TTops and converts, but right now we are talking about performace between two very similar cars. I was just using examples to stress the sense of speed/stability/understeer/traction (like how it can trick you to thinking something) vs what you are actually doing on the road/track. I understand that the coupe is the most efficient. I'm talking about at an everday standpoint, when there are so many varibles that it may makes the result become diluted and so they are similar in numbers. I'm not saying I an expert of any kind. I don't plan to be a hardcore track racer or anything.

I was just saying how much of a difference in actual performce at stock point and then maybe a modded point do you see a open top car vs. a coupe car; and in particular our NSXs. I know there is chasis twist, I can feel it, but feeling something in a car only holds some truth to actual reality, like the sense of speed/acceleration. I've driven a coupe NSX, but not extensively. The only difference I noticed was that it does not have the left to right sway when you go turn hard on a bumpy road since the NSX-T is not as rigid, it bounces and sway left to right. My TTop Zs did it too. But I did not notice a faster acceleration or getting from point A to point B in a curve faster when I was in the coupe NSX. Again, I am no expert at road driving, but this is just what I've noticed and I didn't thoroughly drive the coupe (and by that I mean driven it daily or for a long period of time to actually get a feel of what it has to offer) as I did not own the car.

02#154 is the only one that seem to agree with me, or actually put input into the actual difference. The 6-7 seconds depends of the length of the track. Driver error and skill can cause the numbers to be pretty loose between the two cars since he does not a professional that only deviates 1-2 seconds from his lap times. This was wat I was looking for, was the difference in performance measured, on paper vs. the feeling of you are faster because your car weighs 100 lbs less and has slighty or a lot (watever it may be, I would like to know this too, sahtt sorta answered that to an extent) better weight distribution/rigidity.

I like effiecency too and my reasoning is that an open topped car is versatile as it can open or close the top for various needs. It sacrifices some performance for more appeal, but obviously Honda tried to compensate. So how much efficiency is lost in performace and handling. Obviously 100 lbs weight difference does little to the acceleration/braking numbers. So the questions lies on actual turning performance or handling. Let's say the top is taken off to compete against the coupe. The top removes idk, ~20-25 lbs off the top, so the center of gravity is lowered. The rigidity is even looser now since the the top is not there to help. Would this balance/combo make it perform worse on the track or better better versus if the top was replaced.

I am just curious about people's experience; mentally vs. actuality/reality. I'm seriously not trying to spark a debate about which one is better. We all know the coupe would be the number one for TRACK USE. I am talking about overall use, the jack or even master of all trades.

 

[02#154]

It seems that the people on this board tend to read into words; you stated your question and they heard "is a coupe really better (for performance) than a targa?"

I think we all agree that the bottom line is that a coupe "can" perform better, and in capable hands, will perform better. Bu I agree with you that nobody has really answered your question which really boils down to: "can an average joe extract noticeable (not just measurable) real-world performance from a coupe vs a targa NSX?" My opinion is that no, an average guy cannot. Put an average guy into a coupe and have him hot lap it for, say, 3 laps. Then let him lap in the targa for another 3 laps. He's not going to come in to the pits and say, wow, that targa's a lot slower. And the longer the lap times, the less he'll feel a difference.

Just my opinion.

J

 

[sahtt]

It seems that the people on this board tend to read into words; you stated your question and they heard "is a coupe really better (for performance) than a targa?"

I think we all agree that the bottom line is that a coupe "can" perform better, and in capable hands, will perform better. Bu I agree with you that nobody has really answered your question which really boils down to: "can an average joe extract noticeable (not just measurable) real-world performance from a coupe vs a targa NSX?" My opinion is that no, an average guy cannot. Put an average guy into a coupe and have him hot lap it for, say, 3 laps. Then let him lap in the targa for another 3 laps. He's not going to come in to the pits and say, wow, that targa's a lot slower. And the longer the lap times, the less he'll feel a difference.

Just my opinion.

J

I can't speak for everyone else, but I agree with that for the most part. I was simply stating why the coupe is better and then you have to decide for yoursel if why it's better can transmit in to a better 'value' from your perspective. Theoretically it's quite possible that people could have faster lap times in an automatic c6 than a z06 simply because the first is much easier to drive. Because every single individual experience will differ, you have to rely on the science behind it and let others come to their own conclusions. Either way, if you notice the difference on the street, especially if both cars are relatively stock, you are probably driving too hard.

 

[Ski_Banker]

I get it, and agree 100%. The Targa's chassis flex may make it, say, 98% as controllable in a turn (at threshold of tire adhesion) as a Coupe. But if you are cornering anywhere near 98% threshold in an NSX, on public roads, you are driving way way way too fast.

But, as everyone knows, the Targas (with the top off) do have a squirrelly feel in the steering wheel going over bumps. Don't let this wet noodle fool you though -- even with the top off, I can't tell a bit of difference in how fast I can *actually* take a turn.

 

[NSX GT]

Correct me if I'm wrong. I'm not sure if I'm stating facts or just my opinions and based on Prime and other 91-92 NSX owners. I have been noticing a lot of early model Coupes (91-92) have similar problems.

1.Transmission/Clutch (production problem on some cars)
2.Antenna Issues and power window motors (most cars have this issue)
3.Climate Control unit (????)
4.Radio / Speaker Amps (age of car)
5.Camber Issues (Tires wear unevenly really quickly)

This could be due to a couple of issues. Maybe early model production cars or simply the age of the car. 16+ years old, things are going to go out. I have a 93 Coupe and so far none of these issues have come up yet. "Knock on Wood"

Would it be safe to say that by the time the NSX-T (95+) most of the same issues have been resolved? Is this true? Maybe some of NSX-T owners can comment on their experiences.

Final word: I'd still go for a Coupe. I've had Targas, T-Tops, Convertibles tired of that scene. I also experienced a lot of flex on the cars going over bumps and moderate turning speeds. Or maybe I'm just getting too old for the "on and off" BS.

 

[pvmike]

1. Snap ring failure is a problem that only affects a number of early model NSX's. Read this: http://www.nsxprime.com/FAQ/Troubleshooting/transmission.htm

2-4 are age related problems. The actual components have not changed over all model years (save for the window regulators, and it's an easy fix: http://www.nsxprime.com/FAQ/Troubleshooting/windows.htm)

5. Excessive tire wear occurs if the car is lowered enough so that you cannot align to factory specs.