Racelogic GPS Performance tester

So installed it on the windshield, and off to the roads that are somewhat straight nearby. Roads were 90% dry, rained during the night, temperature a nice cool 12C, tank was full unfortunately, but didn't have time to run it down to 1/4 full So not fully optimal situation, but probably the best I'll see until spring.

I started with the G-meter. In deceleration mode, I tried a few times, locked the front wheels half the time, best result was 0.96. Not bad. Then I drove to a roundabout, and just went round and round, faster and faster, until it started to slide. 1.00G! A result I'm happy with. On a hot day I could probably go above 1.00.

So it was time for acceleration. Here I had hoped for a 0-100 kph time starting with the digit 3. The holy grail in a way. In theory my HP and weight should be able to do it I think. I was disappointed.

This Pantera is damn difficult to launch. I've had a lot of dragrace experience, but mostly with 450 HP musclecars, where, besides getting them to hook up, the rest was easy. In the Pantera, I had a couple of challenges. First to find the right revs/clutch movement to hook up. Felt really slow, but wheelspin killed any good run, I had to get away without wheelspin. Next after a very fast run through 1st gear, getting the lever out of first was only possible when not accelerating, when accelerating it felt locked into 1st gear. So had to ease of the gas. Then the last challenge, the Z travel from 1st to 2nd. I had my eye on the shifter everytime, didn't want to hit the wrong gear, and it took forever to get from 1st to 2nd that way. I'd estimate half a second.

My first run 0-100 kph (not 0-60 mph) was 5.0 seconds. Then a few 4.8 second runs while practising, still with the occasional aborted run when I didn't get it right. Got down to steady 4.5s and in the end after playing with my ICE ignition, I got 4.4s.

(Picture: Ignore the 0-100-0, didn't try an acc and decel together. 0.7s 50-70 is quite impressive IMHO)

Another interesting measurement it had done without my knowing, the max Gs accelerating. 0.95 is a high number, but of course only in an instant, so I must have hooked up really well at least for a split second once.

So 4.4 seconds. Well if I'm optimistic, I could say that I had 100 lbs of gas with me that I didn't need. And some 3.x claims are indeed 0-60 mph performance, which is only 0-96 kph. Regardless, I'm sure this Pantera has the power to do 3 second runs, but the shifter pattern/driver combination adds several tenths to the time. Guess that I for now have to be satisfied to have a 4 second car.

This is of course for me only the starting point. Now I have a tool so I can finish the proper tuning of my Pantera as described in my book. Playing with jets might add some power, who knows? So maybe I can get a 3 second time next year on a really dry day? I'll let you know

BTW, the Pantera took a beating today. All these runs has probably put more wear on it than normally in a full year (unless I'm overtaken by a GT40 at Spa of course). It worked well, no overheating, nothing broke. But I'm a bit tired myself

Very impressive real world numbers.... Great job...

Hi Mikael, its a nice way to spend a day ;-) Perhaps if you change your gearing to 3.77:1 and shift at 6300 you will do exactly 60mph in first! might be a slightly slower launch but don't you think that will improve on the time overall?

What would be cool to see also are the sectors from 100-200km/h or 150-250km/h if you should pass by a German Autobahn!!

With the above mentioned gearing (which I happen to have but just not the BHP/Torque like you) you also gain a very comfortable RPM range when cruising. I believe its around 2100rpm @ 100km/h (60mph) not to mention the top speed increases significantly.

I know yes, we can just keep pooring money into our cars for minor achievements. It doesn't matter!

Jan

Have you tried launching in second gear instead of first? I would think with the right horsepower you could do it. After all, you need to get -out- of first pretty darn quick.

Asa Jay

I want help out, 0-100 KPH = 0 to 62.137 MPH 4.4 is not bad! Great tuning tool.

quote:

Originally posted by No Quarter:
I bought such a thing recently, and have then been sitting waiting for a day with dry roads, happens rarely in these parts of the world. I bought it for a couple of reasons.

Primarily as an aid in tuning my cars. As those of you that have had the pleasure(?) of reading my book knows, the first parts of the engine tuning process can be done in your driveway with a vacuum gauge. But the later parts of the process requires trial and error testing on the road/track and adjusting. Doing that kind of testing with a 300-400HP automatic musclecar was doable. But with a higher HP manual trans Pantera, holding on to a stopwatch or noting the speedometer when on a public road at double the legal speed, well it becomes both less accurate and more dangerous. With the Racelogic, one less concern.

The second reason is that I'd like to know what it can do. 0-100 kph, lateral Gs and all that. It's rare in this forum that performance numbers are quoted. During this post I will quote mine, knowing full well that this is just the calculation of one GPS, could be inaccurate. So bear with me, just letting you know what it said, and I'll let you be the judge of the accuracy.

They sell software (an app) that you can use in a modern smart phone (Apple or Android) that does the same things. I don't now how accurate it is (there are several different apps at different price points.) Modern smart phones have accelerometers and GPS so they should work as well and they have a superior Graphical interface. I am planing to try mine when I get my new 635* hp motor installed!
* estimated

I think a real world 4.4 is great, this corvette is supposed to be 3.8 sec 0-60 and the best they could do on the day was 4.8sec.

https://www.youtube.com/watch?v=jJl0SW6zcZ8

What kind of power does your car have?

quote:

What kind of power does your car have?

An MME 408 Cleveland, dynoed at the time of purchase to 593 HP on an engine dyno

quote:

Have you tried launching in second gear instead of first?

I tried once, didn't work out, would quickly eat my clutch

Today I had time to look at the software, and found the data pictured below. Note that in Dragracing, you always round the number down, an 8.99 is an "8 second run". So if you accept that way of thinking, I had a 4.3s run

Kjeld

Found another look at my best run. A whopping 0.5-0.6 seconds to change gears...

i think this may help to understand why the new Vett was unable to make it's claimed 0 to 60 times. It is a front wheel drive car and their for the mass over the rear wheels is ineffective on keeping the rear tires from spinning, this is not my opinion buy the opinion of the G.M. engineers. You might find it interesting that G.M. plans to reconfigure the Corvette to mid-engine by 2017 in select models and all Corvettes by 2020, the reason is the exact ratio of rear to front weight is better achieved with the mass of the motor over the rear wheels..... we could have told them that along time ago. Your car halls ass!!!!!

quote:

Originally posted by No Quarter:
Found another look at my best run. A whopping 0.5-0.6 seconds to change gears...

Porsches also use all-steel balk-ring synchros made by ZF, plus they use a stretchy cable operated shifter; their gear changes are not drag-race-quick either. Different games....

quote:

Guess that I for now have to be satisfied to have a 4 second car.

Well sort of. I still wanted to have a 3 second car, because I think the power to weight ratio should make it possible. It's been winter, but today is March 15th. That date is big in the classic car community in Denmark, because many have insurance that is cheap but also doesn't allow driving from Nov 16th to March 14th. So today is first day of spring. And it's optimum conditions to do performance runs I think, at least the engine likes the approx 5 degrees C air. Just like my boat, it's always the fastest right when I put it in the water, the bottom is clean and the engines like the cold air. On the other hand the tires on the Pantera grip better when hot, and in fact traction is the deciding factor here. Maybe

Regardless, it was time to test. But first, what had happened during winter? As readers of my book (sorry Doug ) know, getting the best from your engine requires some trial and error both on the ignition timing and also on the carb A/F settings. I had already in the autumn trial tested different ignition curves, the ICE systems allows me to change the curve from my seat. I hadn't gained much, which I guess is not surprising, because I had the curve in there that MME (the engine builders) had recommended, they had kind of done much of the trial and error for me on their dyno. And on the carb settings, the carb was also customized on the MME dyno, so there probably wouldn't be a lot to gain.

But I had to try. I want a 3 second car! So I did a few changes this winter to the carb. And then sat waiting for insurance and good weather. All that came today. So it was time to test.

And OK, I'll admit it up front, I set the RaceLogic for 0-60 mph which is of course a bit easier than 0-100 kph, but I also did that because during the winter when reading magazines like Motor Trend and seeing which cars are 3-second cars, they always measure 0-60mph.

I also optimised a lot of things before going testing, all old dragrace tips, that will reduce weight, rolling resistance, inertia and engine resistance. Just as the factories do when they try to get a good number. Only thing that still worked against me was a more than half full gas tank, probably had 50 lbs more onboard than I needed. But I didn't have time to empty that tank, it was now or never.

My main testing road is near a hardware store that's open Sundays, they close at 2pm, so I sat very impatiently waiting for that. Left home at 1:30 pm, to take a good drive to get the oil warmed, both in engine and the ZF.

First a couple of attempts went up in smoke. I have two stretches to test, the asphalt is grippier on one of them, but it's also slightly uphill, so I tried both. First decent attempt was 4.11. Close, so I knew there was hope, I just had to get a good start and a good 1-2 shift in the same run, then I could be in the 3s. Maybe
Then 4.06
And then 4.03
And 4.01!
Let me just say that during these runs the car was very steady in its performance, the shaky part was my attempts to get off the start line and to a lesser degree the 1-2 shift
Then 4.05, and then 4.10.
Hhmm, it seemed outside my reach. And while the area was closed for business, some people drove there, maybe they thought I was a bit too noisy/dangerous, so I knew I had limited time.
A 4.57 didn't really help my mood. Then 4.07.
4.25
Then I changed the revs for my starts, because this was going nowhere
First attempt 4.10, and I knew I could do that faster because my 1-2 shift was not good. I just needed to get a good start and a good 1-2 shift in the same run, the car was giving me the power every time, it was up to me
Then finally:

3.92!

Yes! I have a 3 second Pantera. Not in theory or according to the engine builder or some know-it-all, no, based on real measurements, and including my lack of experience in getting a high HP car with manual dog leg trans off the line.

To celebrate, I decided to do my first selfie, hope George doesn't think it's too strong for this Forum

Here are some of the data RaceLogic keeps on an SD card. A table of my fastest run. I know it's probably mathematically impossible to avoid, but I'm still impressed it can reach 60 mph in less than 60 meters

Here's the graph. Still it clearly shows my very slow 1-2 shift. Has anybody built a PDK for our cars?

Also it looks like 0-100 kph is also 3.xx seconds

This shows that I had good grip at least once on most runs. Almost 1 G of acceleration, then you don't need more power, you need better traction and a better driver perhaps

Just curious. Did you ever try a second gear start? It seems counter-intuitive and might not be good for the clutch but just wondered.

Asa Jay

quote:

Did you ever try a second gear start?

I tried that in autumn, the car didn't seem to like it.

quote:

Originally posted by No Quarter:
... Has anybody built a PDK for our cars?
...

I don't know what "PDK" is, but here is an automated paddle shift system that states it works with the ZF
http://www.supercarsllc.com/ne...nual-paddle-shifters

PS...I found the discription of the dual clutch transmition (PDK), very interesting. I see where it would eliminate shift times

Just as a follow up after this abuse, I checked the Pantera for wear etc. Tires looked ok. Clutch hole showed a considerable volume of clutch powder, so I probably wore the clutch quite a bit. The plugs looked fine, no sign of any overheating despite repeated high rpm runs (NGK "9" race plugs). And last but not least, took off the valve covers to check the valve train, nothing to report that I could spot.

I like your scientific test method.

It looks like your Racelogic tester can provide a lot of useful data.

Rocky

I have been toying with the idea of attempting to cobble together a "telemetry / data acquisition system" for my car, but it seems to me that starting from such a basic, non-electronic design as our Panteras, the cost and complexity of the sensors will quickly get out of hand. A performance tester like yours will atleast give you "actionalble" information - once you establish a "Baseline" (as you have).

Rocky, for the RaceLogic you can buy modules that read rpm and other things, then you start to have more data to work from. For me, this is enough. I'll use the RaceLogic on my Longchamp and Camaro when spring is here, just to see 0-60 times and to fine tune them.

Nice 0-60 time!

I've got a few questions for you.

What type of tire are you running? Size, model and age?

What kind of clutch do you have? Single disk, double? Centerforce or McLeod?

What was your approximate launch rpm on your 3 second run?

I'm running a 408 and plan to do some autocrossing with it and your information would give me a hint on where to start.

Thanks

Tires are Michelin Pilot Sport, 335/35 ZR 17, 4 years old

Clutch, I don't know, haven't had to deal with it yet. If it's visible from the hole on top of the ZF, tell me what to look for?

I don't remember the exact rpms, it was done by feel and hearing. But the 3s time came with much lower rpms than I had tested before, and it gave a smooth non-wheelspin start. Maybe it was around 4000 before, and the 3s was at 2500-3000...

Good luck in autocrossing, show those non-Pantera drivers what they're up against!

It would be interesting to see your racelogic tester in another modern supercar to get an idea of the real world differences. I think the old girl might surprise.

Sounds like a great idea. Unfortunately I don't know anybody with modern supercars due to our car taxes. But someday...