Performance meter results

Andy Besic · 02-26-06, 10:58 AM

I broke down and bought a G-Tech pro RR performance meter. I wired in a Cigarette lighter plug and hooked everything up. Entered vehicle weight of 2850# (full of fuel w/driver). Calibrated the RPM's and accelerometers. I'm ready to go, except in Chicago it is 33 degrees, sunny, 15 mph north wind, streets have some dried salt residue and I have Bias ply Hoosier Street TD tires. Perfect conditions for accurate performance data. [img]/ubbthreads/images/graemlins/lol.gif[/img]

So I warm her up. With an oil cooler and a -3 hose coming from the back of the motor bypassing the thermostat, this take about 15 minutes of normal street driving before I have any oil temp and the tires are warm enough to feel round again! I find a long country road and do a couple of 1/4 mile runs. 10.9 sec @ 103mph and 11.2sec @ 102mph on the way back. These seem to be good numbers to me as I don't have a clue as to the strategies for drag racing, I am road race only. I used a 2000rpm launch, no wheelspin, and 6000 rpm shift point.
Now the farmers are heading out to see what all the racket is (running straight pipes that are really loud at full throttle especially in the cold air!) I decide to find a parking lot to do some skidpad work. I have worn out my welcome here [img]/ubbthreads/images/graemlins/banned.gif[/img]

School parking lot has lots of light poles and lots of salt... .79 G's, lots of unpredictable sliding around, HUGE engine noise thundering off of the buildings.....OOPs we are drawing a crowd time to move on...
I find a large, new parking lot in a park with no light poles and no salt! I manage 1.12G's in one direction and 1.07G's in the other and many parking lot circles [img]/ubbthreads/images/graemlins/beerchug.gif[/img]

Fun stuff [img]/ubbthreads/images/graemlins/banana.gif[/img]

I can't wait until I can get some real heat in the tires and put my race pads in for some Brake tests!

Paul Thompson 'Hooligan' · 02-26-06, 11:35 AM

Great figures Andy!

The best we've achieved here in the Uk is 11.83 @ 113 Mph - also on a public road, but with silencers and sticky Avon slicks.. View other figures By Clicking HERE

What gearbox/motor combination do you have, did the G-Tech give an estimate of HP?

I know what you mean about open pipes - they sound awesome, inside and outside the car! but seriously loud!! Sounds like you had some great fun, next time perhaps think about getting some video to post.. [img]/ubbthreads/images/graemlins/smile.gif[/img] so long as it does'nt get you into hot water though! [img]/ubbthreads/images/graemlins/blush.gif[/img]

Pantera1889 · 02-26-06, 12:57 PM

The G-tech is awesome! I ran my F-150 Lightning at the track with the G-tech installed. I made four passes(best of 12.57 sec.) and the most it was off was .05sec!!! That's incredible! One thing to note,the MPH was always 5 high. It happened every time.

Nice #s by the way!

Russ Noble · 02-26-06, 01:10 PM

[ QUOTE ]
so long as it does'nt get you into hot water though!

[/ QUOTE ]

Yeah, couple of months back some hoons here in Christchurch videoed a few wheelies they were doing in a WRX wagon. In the end they took out a lamp post which did nothing for the car! [img]/ubbthreads/images/graemlins/banghead.gif[/img] They posted the video on a website, the cops somehow saw it and charged them with dangerous driving!! [img]/ubbthreads/images/graemlins/beerchug.gif[/img]

It really is much better to do those sort of things on the track. But I fear there's a little bit of hoon in all of us. [img]/ubbthreads/images/graemlins/bash.gif[/img] So be careful out there [img]/ubbthreads/images/graemlins/nono.gif[/img] Make sure you obliterate the number plate!! [img]/ubbthreads/images/graemlins/driving.gif[/img]

Regards

Andy Besic · 02-26-06, 03:07 PM

Paul

Engine is a 331W internal balance full roller with custom hydraulic cam and 750 cfm 4bbl. Full specs and dyno sheet listed in my for sale post. UN1 with 3.44.

G-Tech calculated 365 ftlbs of Tq and 299Hp. My flywheel dyno sheet from the builder shows 395TQ and 409HP.

The lateral G's shocked me because the tires never really got hot and sticky. The Asphalt pavement was newer, smooth and uncoated though.

Looking at the numbers at the link you posted, it doesn't seem possible to get the 1/4 mile numbers I did. Does anyone have any thoughts?

I plan on some video in the future, I don't have a camcorder or the talent to upload video yet. [img]/ubbthreads/images/graemlins/loser1.gif[/img]

Ron Earp · 02-26-06, 03:20 PM

Hi Andy,

I have a G-Tech meter as well and have used it at the track. As Ron mentioned, it has compared very well with tack figures for me BUT - it took some work to get it like that.

The weight needs to be correct, and, the unit calibration must be done exactly as written (mine is the older model that you had to hold level, right, left etc to calibrate. The newer ones do that automatically. Then, the mount must be absolutely firm, and, the mount must hold the unit level - we used a square and plumb to get it that way. Before all of this we'd get results that were off, like yours.

If you are getting true 10.9, or basically 11 flat quarter mile times your trap speed would need to be in excess of 120mph, unless you had absolutely horrible wheel spin. And, if you had that your 60 ft time would stink and you wouldn't be getting 11 flat times I doubt.

In general the quarter mile charts would have you, with 2850 lb car, at over 425 flywheel up and trap speed of around 125mph - if all worked as planned. But to have traps at 102mph, something is amiss I think.

The G-Techs can be accurate, I firmly believe that as I've seen them match up well, within a tenth or so and a couple mph trap, but I think yours if off due to the discrepancy with trap time and mph.

R

Andy Besic · 02-26-06, 03:28 PM

I found the problem! The G-tech user is an idiot! (me) I didn't read the results from the summary, but the time@speed screen which ended at the above mentioned results. Little did I know you can scroll to the right and see the REST of the run. DUH. Any way I REALLY pulled a 12.9 and a 13 flat. From the look of Pauls link that seems MUCH more accurate.

Regards
Technically challanged...Foot in mouth.

Paul Thompson 'Hooligan' · 02-26-06, 05:06 PM

A 12.9 on road tyres is good in my humble opinion! The UN1 means shifts of 0.5s min and I guess you were in 4th - just?
If so, hanging onto 3rd would save a bit too.

I always consider you guys over the pond to be the natural experts at drag racing, you have so many race locations and a much much wider experience of V8s in general. I'm also pleased re the G-Tech Pro RR, I was considering getting one myself, I have the earlier system Ron spoke of which again, works reasonably well if correctly configured. The system you have looks the biz to me (being a bit of a techno-geek!) so I may well invest in one too. I should think for testing launch techniques, tyre pressure settings, engine modifications, different fuels, it would prove very useful.

One last thing though, Ron once spoke of us having to try 'high rpm' launches before we got low ETs.. Just how high is high? surely anything over 2-3k will just light the tyres..??

My avatar shows a launch at Brighton Speed Trials in 2nd gear at about 2800-3000 rpm! [img]/ubbthreads/images/graemlins/confused.gif[/img]

Ron Earp · 02-26-06, 06:32 PM

Andy, that explains a lot - now the times look a lot more reasonalble - 13 at around 103 is on the money.

Now, the question will be, where did all that flywheel hp go if the motor was rated at 409hp and you weigh in at 2850lbs? If you got no spin on launch then something is up - that car should trap at a high speed even if the ET stinks.

Paul, next time I come over I'm bringing some M/Ts or some Hoosier drag slicks - do you guys use these over there? Also, remember we're comparing a lot of strip times with Brighton, and Brighton has a horrible surface as I can see from the pictures. Some heated and sticky slicks, low tire pressure for some wind up on the wheel, softer spings to absorb some launch, and it should be possible to launch without lighting on the tires - but that will put horrible stress on the transaxle, similar to lugging in top gear.

R

Andy Besic · 02-26-06, 07:46 PM

Ron
The times were 12.9 and 13.0 @ 112mph and 113mph.
I was wondering about the HP also. They dyno'd the motor with their 2" headers choked down to 1 5/8" and no air cleaner. I have the stock GTD 1 5/8" headers that I believe have horribly shaped port openings.
I built the engine for a big flat torque curve and excellent reliability and that is what I got. In retrospect this data jives well with my last track day observations... I was getting better lap times at Road America shifting under 5000rpm than using 6000rpm.

These cars are sooo damn fun!

Cheers all