0-60 for a 914/6 with 3.2? Options

[Jett]

(IMG:style_emoticons/default/smile.gif) I am thinking about an i3 to deal with stop and go commute traffic and at work the EV’s have the best parking spots.

[dr914@autoatlanta.com]

https://www.youtube.com/watch?v=mjp1hi28rug

[gms]

The 3.0 car I had years ago ( @GMS drove it) would do 0-50 in 5 sec or less with crude measuring equipt. The rev limiting rotor would hit the wall around 57 mph in 2nd gear, so shifting twice is really going to slow you down, unless you don't care about damaging the car. That engine had tons of torque, three different people accidentally started from a stop in 3rd and didn't stall or kill the clutch, and 3rd tach'd out around 75 mph

The Dallas Beer Run 1996...Yes that was a fun drive @IronHillRestorations , I will never forget @a914guy 's face.

[jd74914]

Not bad . . . but you need AWD! (IMG:style_emoticons/default/laugh.gif) There is a reason the 959 had AWD.

Tractive effort quickly becomes the limitation unless you're willing to run 18" wide rear rubber and to deal with the issues rubber that wide brings with it.

I think you'd gain quite a bit with good traction control as well. Might as well maximize the area under the tractive force curve. I haven't seen anyone with any real traction control in a 914 yet. Should be interesting when that happens.

[Superhawk996]

Not bad . . . but you need AWD! (IMG:style_emoticons/default/laugh.gif) There is a reason the 959 had AWD.

Tractive effort quickly becomes the limitation unless you're willing to run 18" wide rear rubber and to deal with the issues rubber that wide brings with it.

I think you'd gain quite a bit with good traction control as well. Might as well maximize the area under the tractive force curve. I haven't seen anyone with any real traction control in a 914 yet. Should be interesting when that happens.

The problem with traction control is that it isn't very effective without full integration to the powertrain managment.

Early traction control systems were brake control only tied into the ABS pump. They weren't very good. Then traction control integration extended to include spark control (primarily control of spark retard) so able to dial back powertrain torque to a very limited extent.

It wasn't until OEM's went to throttle by wire that traction control was decent with direct CAN communicaiton between the chassis controls and powertrain controls so that each knows exactly what the other is doing and they can coordinate efforts.

I've been involved in the development of ABS/Traction Control/ESC systems since 2000. I briefly thought about doing ABS but then remembered why I wanted a 914 again in the 1st place. Simplicity. So I quickly put it out of my mind. So many variables involved that I personally don't deem it to be worth the effort but I'm sure someone out there will eventually do it but to do it right and to do it well, will involve some significant work!

[jd74914]

Not bad . . . but you need AWD! (IMG:style_emoticons/default/laugh.gif) There is a reason the 959 had AWD.

Tractive effort quickly becomes the limitation unless you're willing to run 18" wide rear rubber and to deal with the issues rubber that wide brings with it.

I think you'd gain quite a bit with good traction control as well. Might as well maximize the area under the tractive force curve. I haven't seen anyone with any real traction control in a 914 yet. Should be interesting when that happens.

The problem with traction control is that it isn't very effective without full integration to the powertrain managment.

Early traction control systems were brake control only tied into the ABS pump. They weren't very good. Then traction control integration extended to include spark control (primarily control of spark retard) so able to dial back powertrain torque to a very limited extent.

It wasn't until OEM's went to throttle by wire that traction control was decent with direct CAN communicaiton between the chassis controls and powertrain controls so that each knows exactly what the other is doing and they can coordinate efforts.

I've been involved in the development of ABS/Traction Control/ESC systems since 2000. I briefly thought about doing ABS but then remembered why I wanted a 914 again in the 1st place. Simplicity. So I quickly put it out of my mind. So many variables involved that I personally don't deem it to be worth the effort but I'm sure someone out there will eventually do it but to do it right and to do it well, will involve some significant work!

Very cool!

I'm totally onboard with the first part-especially in terms of retarding spark, and the last part regarding the amount of work. Everything thinks pulling ignition timing is magic but you're really not modulating power well with that knob. Perhaps enough to calm a race engine's lopey idle. (IMG:style_emoticons/default/laugh.gif) I'm not convinced you need to go to the OEM extent of integration with throttle controls given that we don't really care about emissions or efficiency. I've had pretty good experiences optimizing wheel slip with bike-engined cars with cable throttles. Admittedly it's been using high end ECU's (Life Racing, etc.) with high speed engine position tracking (FPGA-based to maybe 5 degrees), not the standard MS-maybe that's the difference? Dying to play with tuning on a DBW car-no one I know plays in that $$ range though. (IMG:style_emoticons/default/blink.gif)

[Superhawk996]

Dying to play with tuning on a DBW car-no one I know plays in that $$ range though. (IMG:style_emoticons/default/blink.gif)

Agree on price being out of the box. Typical prototyping ECU's capable of doing what is proposed are not cheap. The engine emissions end of it isn't the problem. It's the fidelity required to do wheel control in a decent manner. The latency between sensors, and actuation and the time to calibrate and tune. Like I said, early systems sucked - partially because the controls weren't well developed but also becuase the latency was high. You ended up with wheel flare, then the system would catch it but overshoot and drag the wheel speeed too low and then you would get a acceleration pause. Then another flare and another pause. Really poor modulation of wheel slip overall vs. what is the norm today.

dSPACE Microautobox =$40K on lowish end for the hardware and then you still need their software suite to run it so add another $20K.

The cheaper solution is something like Speedgoat hardware and MatLab/Simulink software will still be $20k. Not exactly cost effective for our hobby world use.

I think a very basic traction control could likely be done with something on the order of a Rasberry Pi and using a CAN transceiver interface to to the communication between sensors and actuators. But . . . I have no desire to spend my day writing code to make ABS & traction control work on a one off basis for a 914 and it would likely be closer to the early 2000's era of traction control. I know I wouldn't be happy with it vs. what has come to be expected in any production automobile today.

[Marv's3.6six]

I would think a six mated to a 915 trans would show much better 0 to 60 numbers.

Back to the OP question........

My brother estimated mine at just over 3 seconds. I have a close ratio 915 and an RS spec 3.6 993 engine with Toyo R888 race rubber. The technique was to dump the clutch at just over idle, then nail it thru first and second gears. (IMG:style_emoticons/default/driving.gif)

[oakdalecurtis]

Just a small point of mind blowing reference for this thread:
A Top Fuel dragster accelerates so quickly that its already passed 60 mph by the time the rear tires have crossed the start line (300 inches), at .54 seconds!
(IMG:style_emoticons/default/aktion035.gif)

[sixnotfour]

Just a small point of mind blowing reference for this thread:
A Top Fuel dragster accelerates so quickly that its already passed 60 mph by the time the rear tires have crossed the start line (300 inches), at .54 seconds!
(IMG:style_emoticons/default/aktion035.gif)

But Cannot Turn On a Qtr. (IMG:style_emoticons/default/lol-2.gif)

[Cracker]

I would think "at best" the time would be in the 5-6 second range. I have driven many 914/6 conversions and they nearly all leave allot to be desired - acceleration wise - no way they are very quick. Andy's launch on the WCR autocross is as strong as I have ever seen a 914 accelerate (six, of course)...that's a "3.6" though! My 911/ 3.2 was fast back in the day but is a dog by comparison to modern cars. Axle hop was also really bad the two-times I actually dropped the clutch...yikes!

PS: I kind of always preferred the 50 to 160 time... (IMG:style_emoticons/default/happy11.gif)

Cracker

[sixnotfour]

(IMG:style_emoticons/default/agree.gif)
rolling start race with a 70 Z/28 stop light to stop light almost 1 mile..
MY SIX ralph meaney 2.4 special...boy was that guy pissed at the red light..twice..ya I was 22..

[Superhawk996]

(IMG:style_emoticons/default/agree.gif)
rolling start race with a 70 Z/28 stop light to stop light almost 1 mile..
MY SIX ralph meaney 2.4 special...boy was that guy pissed at the red light..twice..ya I was 22..

Not bad for a 914 but . . . 1970 Z28 is 0-60 in 5.8 sec per Car and Driver archive. Not at all fast by modern standards.

For reference a 2019 Toyota Camry XSE V-6 does 0-60 in 5.8 seconds.

The world has changed.

I do like that your 2.4L was around a 6 second car. I'm building up a 2.4L with roughly that 6 second goal in mind. Not that I'm expecting to win and drag races, but rather that I can at least keep up with the modern cars. I'll pass em' later when the road has some turns! (IMG:style_emoticons/default/biggrin.gif)

[Cracker]

HOPEFULLY, this driver only goes to "Show & Shines"...where precision does not matter! Hilarious. Hell-o George. (IMG:style_emoticons/default/bye1.gif)

Cracker

https://www.youtube.com/watch?v=mjp1hi28rug

[Chi-town]

If you're looking for the "push you back in the seat" acceleration in a 914, good luck.

The short wheelbase of the car will always lead to traction issues as there it no real "weight transfer" to the rear wheels as the weight is already there so there is no real leverage. You could go with a really sticky R compound tire and hope the drivetrain stays in one piece when they don't spin (IMG:style_emoticons/default/laugh.gif)

That feeling of acceleration is a combination of a lot of factors.
Gearing
Torque curve
Weight
Traction

The 2.7 with the shorter 2.5 gearing in my beater Boxster has a good push (gearing). It is not as impressive as the Sprintex in my R53 Mini (torque vs weight). All of them lack in comparison to my friend's 91' ZR-1 (weight/torque/gearing/traction) (IMG:style_emoticons/default/laugh.gif)

This is a conversation I've had with friends/customers/industry associates time and time again. You can build a car to do anything if you have enough money/time but there will always be a compromise somewhere in the build.

The question I always end the conversation with is, "Do you want to spend the time/money on building a car that will do what you ask or would you rather just invest that money in a car that already does and spend the time driving it?"

[campbellcj]

I've come to realize that if a car doesn't cause you to swear involuntarily under acceleration, it's not really that quick... The great thing about the 914 is that at relatively low speeds it feels (and perhaps also sounds, depending on the car/mods) like you're absolutely flying. It's all about driver engagement vs raw speed.

[Andyrew]

If you're looking for the "push you back in the seat" acceleration in a 914, good luck.

The short wheelbase of the car will always lead to traction issues as there it no real "weight transfer" to the rear wheels as the weight is already there so there is no real leverage. You could go with a really sticky R compound tire and hope the drivetrain stays in one piece when they don't spin (IMG:style_emoticons/default/laugh.gif)

That feeling of acceleration is a combination of a lot of factors.
Gearing
Torque curve
Weight
Traction

The 2.7 with the shorter 2.5 gearing in my beater Boxster has a good push (gearing). It is not as impressive as the Sprintex in my R53 Mini (torque vs weight). All of them lack in comparison to my friend's 91' ZR-1 (weight/torque/gearing/traction) (IMG:style_emoticons/default/laugh.gif)

This is a conversation I've had with friends/customers/industry associates time and time again. You can build a car to do anything if you have enough money/time but there will always be a compromise somewhere in the build.

The question I always end the conversation with is, "Do you want to spend the time/money on building a car that will do what you ask or would you rather just invest that money in a car that already does and spend the time driving it?"

(IMG:style_emoticons/default/agree.gif) on the traction vs back in the seat issue.

For most people about 200whp in a 914 would be enough for a good back in the seat push, which is pretty attainable in most conversions. It's also low enough HP that traction shouldn't be an issue with most good sticky street tires.

I found that over 250whp lead to traction loss in first. Second barely holds about 300whp. Third is jail time. That's with a decent tire of considerable size and going straight.... Around any corner and you can forget about it.


Honestly that's really not that much power in today's world, your average luxury sedan is that fast or faster, and with traction, gearing and quick shifts it's difficult to even compare....

[Superhawk996]

If you want a drag car you want a high Center of Gravity (Cg) to maximize weight transfer. If you're not familiar with the extreme example of this, look up Gasser Hot Rods.

If you want great handling you want a low Cg.

As Chi-Town states, these two things are at odds and leads to built in compromises trying to make a 914 compete with modern AWD performance oriented vehicles.

[mepstein]

A 3.2 is a great engine in a 914 or 911 because it does everything well. Power, sound, tractability, durability and it will start on old gas after sitting all winter. If you are careful about weight reduction, you can drop 150-200lbs from your car and really minimize the added engine weight.

[porschetub]

A 3.2 is a great engine in a 914 or 911 because it does everything well. Power, sound, tractability, durability and it will start on old gas after sitting all winter. If you are careful about weight reduction, you can drop 150-200lbs from your car and really minimize the added engine weight.

Well said,I have dumped all I can out of my car,don't know what the weight was but it all helps.

Even with a 2.2 I can loose traction in first under hard throttle,I have never driven a 4cyl car but would assume the stock gearbox is better matched to that engine rather than a six cyl ? the 2 motors have rather differant power delivery,never timed mine but my son said it was "quick" and he drives a fast car (IMG:style_emoticons/default/aktion035.gif) .