According to CarTest, a very nice program that analyzes auto performance here is what we should be looking for in this new car.

Accodring to the Zapata provided ratios on the stick shift here is what the max mph at each gear will be:

1st gear: 41mph at 7000 rpm
2nd gear: 66mph at 7000 rpm
3rd gear: 96mph at 6940 rpm
4th gear: 129mph at 6810 rpm
5th gear: 150.9mph at 6200 rpm

It does not analyze 6th gear although I am sure it would not be higher than 5th gear as far as speed.

I have the cd at 0.34 and I still get this top speed. Interesting!

Acceleration:
30mph: 2.2 secs
40mph: 3.0 secs
50mph: 4.8 secs
60mph: 5.96 secs
70 mph: 8.3 secs
80mph: 10.2 secs
90mph: 12.3 secs
100mph:16.0 secs

Best 0-60mph method was achieved by DUMPING (and not slipping) the clutch at 1700 rpm.


1/4 mile in: 14.65 secs at 96 mph

Best 0-60mph method was achieved by DUMPING the clutch at 1800 rpm.

Top speed of 150.9 mph came after 131.05 seconds and 25,565 feet later.

 

Same car at 295 HP at 6500 rpm
and 240 lb-ft at 3750 rpm

0-60mph: 5.66 secs (1700rpm dump clutch)
1/4 mile: 14.32 secs at 99.5 mph (1800 rpm dump clutch)

 

In the 260HP car the 0-60mph times are affected by the tire width change in a non-trivial manner only if I enter 255X35X17.

0-60mph: 5.83 secs
1/4 mile: 14.63 secs

Less than 255mm wide or more than 255mm wide does not improve times.

 

intresting.. i was hoping for better figures from the 6spd tranny..... still cant wait until it i see it in the dealerships... i might wanna trade my first gen in.

 

Our Auto tranny Cars showed the following results on CarTest:

0-60 mph: 6.51 seconds
Best launch method: Brake force at 1000 rpm

1/4 mile: 14.99 secs at 96mph

Top speed: 145.9 mph at 5450rpm in 4th gear (178 seconds later)

Pretty accurate for stock cars which tells you that the numbers for the 6 speed car above will be very close to the ones I posted.

 

what did you use as the final gear ratio?

what at-the-wheel hp did you use for the stock hp calculations?


Pull_T wants you to run the program with his car ('98 cobra) to test the results...

1- 3.37
2- 1.99
3- 1.33
4- 1.00
5- .67
Final 4.30

Rear wheel horsepower is 286 tq is 290. Race weight is 3500 with driver. cd is .35 and tire size is 275/40-17.

thanks.

 

The final drive ratios I used is what Acura gives for out auto cars and what Zapata gave for the manual tranny car.

HP is stated at the crank in this program not at the wheels.


For the Cobra at 305 HP at the crank and 245X45X17 which is the OEM tire specs and 3.08 as the final drive ratio which is stock I get:

0-60 mph: 5.26 secs clutch dump at 2000 rpm
13.89 secs for the 1/4 mile run

If I put in what you gave me I get:

0-60 mph: 5.63 at 1200 rpm dump clutch
13.95 secs for the 1/4 mile

 

am i correct to guess that the CarTest program uses the flywheel horsepower?

 

1st -- thanks for the figures and your work!. (I will ask this again (later), but I'm wondering why the simulator didn't set the shifts at the 7200 rpm fuel cut-off?)

If this is a time step simulation with the basic forces of aero drag, rolling friction, and drivetrain losses, there can be a number of errors that will not be accounted for. Dowforce/lift/weight transfer (dependent on suspension design/geometry/car weight) and other forces would not be included (hence, I'm curious about what kind of data gets entered into it.)

Perhaps you wouldn't mind answering a few questions (you've piqued my interest!):


1. Does the program allow you to enter the torque values per RPM.

2. Why doesn't the simulation allow you to set the max RPMS to the fuel cut-off (or does it have a box/input field that allows you to insert the "dead-time" between clutch/gear transitions? (If you have the gear ratios, torque/rpm and the vehicle’s mass (weight), you have the acceleration, without the tire/area/other "drag"/"resisting" forces.

3. Does it have any entries where you can select a rolling and static coefficient of friction for the tires?


I'm wondering about the manuals time in the 1/4 mile. I would expect that the better tires would only help so much with the FWD weight transfer issues and that there could only be so much improvement in the 60-foot times. However, the extended torque curve provided by the headers and CAI would allow for nearly flat acceleration (as related to torque and gear ratio) from 3500 to 6400 rpm. The torque would be increased by 10% across the band and extended from the original 3500 to 5500 rpm range!

4. So, do they allow you to enter some non-fixed torque and rpm values for the manual version of our car?

5. Can you select the loss in the drivetrain (gearbox/diff) and also set the type of loss (fixed or proportional to power [friction])?

I know this is a lot, but the current 2001/2002 CLS with headers, CAI, 235/45-17 Toyos, and 14 lb wheel allowed MIke to get a 14.3 on a 60-70 degree day.


(Oh, boy that is too long...)

 

I put in 7000 rpm as the redline


For the acceleration testsit decides the best optimal points to shift.

 

Yes, all that data is in there. I used the data from 1997 3.2 TL car.

 

Wow, great analysis gravill!!!!! I input the numbers into the car test program but didn't get the same results as you did but i know i didn't correct data.

gravill EricL You two are indespensible on this board!!!! As Ali G says, "Maximum Respect!"

 

Perhaps you wouldn't mind answering a few questions (you've piqued my interest!):
--------------------------------------------

Sure

-----------------------------------------------

1. Does the program allow you to enter the torque values per RPM.

------------------------------------------------------

What do you mean? Per RPM? Torque is fixed. Right?

-------------------------------------------

2. Why doesn't the simulation allow you to set the max RPMS to the fuel cut-off (or does it have a box/input field that allows you to insert the "dead-time" between clutch/gear transitions? (If you have the gear ratios, torque/rpm and the vehicle’s mass (weight), you have the acceleration, without the tire/area/other "drag"/"resisting" forces.

--------------------------------------------------

The simulation allows me to put in the redline rpm point. From there it decides the optimum shifts and it tells you what the MPH speed will be at that given redline rpm poin.

-------------------------------------------------

3. Does it have any entries where you can select a rolling and static coefficient of friction for the tires?
---------------------------------------------------------

It's got:

Max coef. of static friction
Max coef. of kinetic friction
Coef. of rolling resitance
Tire expansion factor
Hot tire pressure
Tire tread to section width ratio
------------------------------------------------------------

I'm wondering about the manuals time in the 1/4 mile. I would expect that the better tires would only help so much with the FWD weight transfer issues and that there could only be so much improvement in the 60-foot times. However, the extended torque curve provided by the headers and CAI would allow for nearly flat acceleration (as related to torque and gear ratio) from 3500 to 6400 rpm. The torque would be increased by 10% across the band and extended from the original 3500 to 5500 rpm range!
---------------------------------------

I have the max torque as 232 pounds at 3500 rpm. When I put it at 5500 rpm, acceleration got worse. I also can see a torque curve from the numbers I give the app. At 232 pounds at 3500 rpm and 260HP at 6100 rpm, the curve looks very similar to what folks got from the dynos. There is no prob there. The system is smart enough in that department.

As for the headers: I tried to compensate for the torque by increasing it to 240 pounds and make it appear at 3750 rpm. Maybe I should raise it some more. I also tried to compensate by having that 295HP appear at 6500rpm. More rpm would hurt numbers.

----------------------------------------------

4. So, do they allow you to enter some non-fixed torque and rpm values for the manual version of our car?

---------------------------------------------

The system has the ability to give me the option to put in specific HP numbers starting at 500rpm all the way to redline in 500rpm increments. That, if one is not satisfied by just giving the system the peak HP. I did not tried that but I doubt it would make the acceleration numbers very different.

-----------------------------------------------

5. Can you select the loss in the drivetrain (gearbox/diff)

-------------------------------------

Yes. I have Mechanical Frictional Losses for:

Aux 2%
Manual Tranny: 6%
Auto Tranny: 8%
Differential: 4%
Axles and Shafts: 5%
Torque Converter: 3%
----------------------------------------------

and also set the type of loss (fixed or proportional to power [friction])?

------------------------------------------

It is in % of power as you see

--------------------------------------------

I know this is a lot, but the current 2001/2002 CLS with headers, CAI, 235/45-17 Toyos, and 14 lb wheel allowed MIke to get a 14.3 on a 60-70 degree day.


(Oh, boy that is too long...) [/B][/QUOTE]

---------------------------------------

I am going to have to play with the numbers to see how I can get 14.3.

 

Hehe... Hey, I do what I can

 

Eric,
the program does allow you to enter the max torque RPM peak @ torque at 2800k but not the range from 2800-5500.

I have a question for you and the other gurus on this site. If you dropped the car so it had the minimum ground clearence to travel i.e, maxium spring rate and low ride hieght, then would that have an affect on 1/4 mile, 0-60 times and if so how much?

 

Eric,
the program does allow you to enter the max torque RPM peak @ torque at 2800k but not the range from 2800-5500.

---------------------------

Oh is that what he meant. :P SOrry.

------------------------------------------------------


I have a question for you and the other gurus on this site. If you dropped the car so it had the minimum ground clearence to travel i.e, maxium spring rate and low ride hieght, then would that have an affect on 1/4 mile, 0-60 times and if so how much?

-------------------------------------------------

It would make a difference but negligible. As you probably know, the system allows for wheelbase and height adjustements. I left the TL numbers in there.

 

Is the 7200rpm fuel cutoff accurate for the current 01-02 model
CL-S ?????

EricL , are you a mechanical engineer or just a super gearhead ??

I really enjoy reading your informative posts!!!

 

I think 7200 rpm is the fuel cut off for our engine, yes. AN I am sure the same will apply for the 03 car.

As for Eric. I think he is the latter

 

I think the 7200-rpm cut off is correct (even though my tach is a bit off and reads high)

Hmmm… what am I: Engineer, software developer, book enthusiast, math fiend, and lover of all things automotive. (I do enjoy art, music, and other right brain stimulation too…)

Thanks for the compliment. You're very kind...

 

Would it help to use Mike's dyno numbers? Unlike the Comptech dyno graph (with headers), he is getting a torque boost at lower rpms:


(Mike's better high res version is missing [probably due to the picture server -- Photopoint? -- he was using])

If you download the .jpg, it should give enough detail to be of some use...

 

Yes I will use that later tonight Eric. I am ready to get on a flight to NY City for now.

 

Eric lookins at all these dyno graphs lately I am thinking of this:

I think our engine makes more torque at 2000 rpm than it does at 3500 rpm. And Acura deleberately states the rpm range where torque appears to be flat for bragging rights. So when I put in the app. 240 pounds at 2500 rpm I get slightly better acceleration for our 2001-02 stock CLS cars:

1/4 mile 14.95 secs
0-60mph 6.45 secs

What I am going to do tonight is I will take indicative HP numbers from the graph and put them in at 1000 rpm increments in the app and see if there is any difference.

 

*sigh* so you're using 4.428 for the auto tranny and 3.286 for the manual tranny as the final drive ratios in your calculations, yes?

the reason I ask is that zapata's original post regarding the manual tranny ratios was a little unclear regarding the manual's final drive ratio. I want to be certain an error has not been introduced into your calculations...

although, I have my reservations regarding the accuracy of these calculations considering the results for pull_t's modified '98 cobra are nowhere near what the car has run at the track. (indeed, they're slower than your calculated results for the stock cobra.)

 

the acura web site gives 7000 rpm as the fuel cut off. where did you get your 7200 rpm figure from?

 

my V-AFC registers about 7220 when the fuel shuts off in 1st gear...

here is my dyno graph:

 

tank yeah there were abit unclear at the bottom but i think he is using the 3.23 as the final drive.

 

Are you sure it is not redline? Redline is 7000rpm. Fuel cutoff comes always slightly later after the redline.

 

redline is 6.9...fuel cut 7.1K

 

that's cool. since he's going to the trouble to run the numbers, I just wanted to make sure he's got the correct information.

 

from acura.com:

"Redline 3.2 CL - 6300 rpm Type S - 6900 rpm

Fuel Cutoff 3.2 CL - 6600 rpm Type S - 7000 rpm"


I know that other folks have mentioned that their redline and fuel cutoff numbers are slightly different (which I would think is mainly due to tachometer error) but astroboy's dyno clearly shows a drop off beginning at 7200, so...

fwiw, the tl specs don't list a fuel cut off.

does the service manual list a spec for fuel cut off?

 

When someone in NJ gets their 6 speed, I am up for a 0-60 run against my stock powered 5-slushie!!
Although I am not interested in the manual, I won't mind giving anyone a chance to run against an auto.
This should be better than running computer programs

 

OK from Astro's graph I calculated the data at the crank to be (assuming that 290HP is the peak HP):

RPM HP

2500 117.3
3000 136.3
3500 156.5
4000 181.8
4500 207.8
5000 230.9
5500 252.6
6000 280.0
6500 290.6
7000 283.7

This car should do:

0-60mph: 5.94 secs (with 80rpm torque-brake)
14.43 secs for the 1/4 mile

Now I will put in this engine with the 6 SPEED!

NExt...

 

So if SOOPA's engine was in the 03 6 SPEED car, the result would be:

0-60mph in 5.42
1/4 mile in 14.12

Best launch method is 1400 rpm clutch-dump

The top speed of that car would be 160mph in 5th gear at 6650 RPM! Can you imagine 5th gear at 6650 rpm at 160mph! WOW!