Gtech hp

[MaTTSuN]

did 2 runs with it today

first one was 160 hp ha well i had it set to light 2800lbs

2nd run was 198hp set at 3200

 

it may be heavier because i would think its making more power then that but then again that with drive train loss i think my et was 15.50 but i rolled into first did not dump the clutch and i ran a 98mph i didnt red line it in each gear because the engine seamed to run out of stream around 5500rpm

 

if i really knew how much it weighed i could get a better idea of whats going on next time ill go to the truck scale before i do my runs

 

 

im running the stock T3 with 7psi

stock injectors @ 40psi

3" exaust

big azz intercooler

and a megasquirt and spark

the engine is a 81 turbo and im running the 78 5spd

[BRAAP]

My not so humble opinion of the G-Tech-Pro…

 

The G-Tech pro is a neat toy, and can be a useful tuning tool. But nothing more.

 

The HP numbers from Ghetto Tech Pro is about as useful and accurate as hunting Elk with a Daisy Red-Rider bb gun.

 

I did run my G-tech pro at the strip in the Big Block Mopar-Z at the PIR late night drags, (running the GhettoTech on all four runs, the G-tech coincided with the actual time slips on all 4 runs quite closely). That was only one car on one night. I still don't trust it 100%.

 

The G-tech Pro is best used as a tuning tool or for entertainment purposes.

 

As tuning tool, make a run through one gear, typically 3rd or 4th in a manual, plotting the G curve through the RPM range which pretty much mimics the torque production, minus any aero and rolling drag. Make a tuning change then run again and note any changes in the plotted G curve, i.e. is it pulling harder or less at any point, indicating improvement or loss. The plotted curve is quite coarse so the precision of the data displayed is going to be coarse, i.e. fine adjustments/changes wont register. Also as level a surface as possible, and run the same section of pavement for all runs, (preferably a two way pass). Don’t focus or trust the actual numbers themselves, just any improvement or loss.

 

If actual HP and/or ¼ mile numbers are what you are after, you are far better off taking the car to a real dyno and real drag strip.

 

Again, that is just my personal opinion, results may vary, this side up, batteries not included, lack of torque has been known to cause cancer in laboratory Rats, but only in the state of California.

[Challenger]

Hey, red riders are powerfull killin' machines!!

 

Also thats a good idea on the G forces/tuning, never would of thought of that..

[MaTTSuN]

yeah i take it all with a grain of salt but it is fun to get some idea of what is going on and if its getting better

there is also a section in the mega log view that has a hp calculator not sure how well it works but im going to try that one 2

[Tony D]

Don't adjust your weight to make the darned thing read what you expect you're making! That defeats the WHOLE purpose of an objective piece of test equipment.

 

Go to a gravel yard, or other truck scale and WEIGH your car.

 

My 75 2+2 weighed 2695#, ran a 15.50 1/4 mile, and my G-Tech said I had 147HP. Curiously the Dynojet showed very similar results, and consistent with the times so did some of the 1/4 mile calculators I used.

 

But I actually WEIGHED my car. The whole premise of the device is that you need to know the mass you are accelerating, and then back calculate from the known time of acceleration and g-loading. Simple physics and in my case very accurate.

 

BUT you HAVE to follow the directions on the first generation boxes (don't know about the new ones) to make SURE the thing is level, reading the proper acceleration plane, that your weight is correct and verified as you will be testing, and that you do the tests according to the directions (both directions, on as level a piece of ground as you can find, etc etc etc)

 

Using their directions, I was spot on with not only the actual 1/4 mile results (I have run from 15.30 to 15.60 in the car, G-Tech was in the 15.20 to 15.50 region) and the horsepower numbers (depending on the pull it was no more than 5hp off, to spot on with the Dynojet I used).

 

But like mentioned above, the big thing is comparable loss or gain after an adjustment. I was curious, and spent the $75 for the dyno pulls since the shop is relatively close, and I said "whow, I can't have that much, I'm diriving over to the shop to see how f'd this thing really is!" After that, I was a believer. Once I got it dialed in at a consistent place to do the testing, I have a very high confidence in the results of the testing. The numbers are not all that important, but the relative change is...

 

To trust the numbers, you gotta follow the directions. Guessing to make the HP suit your expectations is akin to passing the dyno operator some $ to change a constant on the machine and bump your dynoqueen numbers up so you have a nice sheet to show your friends. I know of plenty of 250HP N/A 2110cc VW's running around Orange County...because that is what the guys showed me on their dyno charts. You would'nt think a 2.1 Litre four banger with dual 40's would make 250HP @ 6200 rpms would you? It will if you tweak the dyno constants...

[cygnusx1]

I know I put down 265HP on a dyno once, so I just bought the G-Tech to back calculate the weight of my car.

 

J/K it is a fun toy. Another excuse to go out to the garage turn a wrench and step on the right pedal.

[ktm]

Innovate's LMA3 has an internal accelerometer. You can use formulas in Logworks 2 and Logworks 3 to calculate horsepower and torque based on the accelerometer (as well as all of the other necessary parameters).

 

I use it to as a means to monitor changes in performance due to tuning differences, etc.

[Pyro]

98 mph in the 1/4 mile with a 3000 pound car (2800 pounds plus 200 pound driver) takes 220 hp if you go by the following formula.

 

hp = weight x (1/4 mile trap speed/234)**3

 

Your traction must be pretty bad. You should be running at least mid 14's with a 98 mph trap speed. For example, a 350z typically runs 14.0 at 100 mph. Try again with some fresh rear tires.

[Tony D]

98 mph in the 1/4 mile with a 3000 pound car (2800 pounds plus 200 pound driver) takes 220 hp if you go by the following formula.

 

hp = weight x (1/4 mile trap speed/234)**3

 

Your traction must be pretty bad. You should be running at least mid 14's with a 98 mph trap speed. For example, a 350z typically runs 14.0 at 100 mph. Try again with some fresh rear tires.

 

So then the G-Tech is low? At the San Antonio Dragway I was pulling something like high 90's and a 15.50 at the top of third gear through the lights. Admittedly I was spinning like crazy on street tires, but it was consistently 1 second faster than the guy in the 76 Silver Coupe that started swearing at me that there was 'no way in hell that engine is stock!'...

 

Yep, from a $100 Junkyard 186K mile 1980 280ZX 2+2!!! Now got 225+K on it, and still running strong. I hear they run the strongest....just before they let go...

 

Incidentally, somewhere I have the weight ticket from the return road scales at the San Antonio Dragway. That was a good Convention...had a blast. Save for that Toyota Truck rear-endo on I-10 in Houston. That caused duress during the vacation.

[Pyro]

Not sure if G-tech is low or not. That formula is most likely off a little to. I have seen 4 or 5 different formulas for hp estimates from mph and weight, and the results do vary by a good amount (±20hp). The formula I used is the only one I remember right off the top of my head. I think maybe the formula I listed is more accurate in the higher mph ranges since it was made for real drag cars that tend to run at least 110 mph.

 

But I did measure 275hp with my g-tech and ran 108 mph with my 2850 pound ride at the track. Using the formula it comes out to 280hp. Pretty close.

[Pyro]

check out this site

 

http://www.stealth316.com/2-calc-hp-et-mph.htm

[Tony D]

I think that article will get linked to my son...

 

"So, what do you need to know about algebra for, anyway?"

 

With the way that article is explained, he should be able to follow it, and I know they're graphing curves in his class now, so it will be a real world example that may open his eyes close to home for an application.

 

I suspected most of those calculators were using Crank HP, that gives me the explanation of the '202' hp I got with that one, opposed to the 150 or so on some of the others (close to the G-Tech and Dynojet number of 147--which are supposed to be "RWHP")

[Pyro]

Yes, those curves should get a motor head son a little more interested in math.

 

Yes, that maybe be crank hp. I have seen it described as crank hp and as wheel hp, so I'm still not sure. But I'm leaning towards crank hp.

 

I'm guessing a manual trans Z would have about 15% loss at the wheels

[Scottie-GNZ]

Does not matter if the g-tech HP readout is high or low or the g-tech is a POS. The only thing that HP readout should be used for is to compare test runs in YOUR car under the SAME conditions. End of story!

[MaTTSuN]

some people likes some people not so much, i wouldnt go so far as to say POS it is a cool little toy and if can get you with in 5-10 hp thats pretty dam good.

i think the G meter will be a good tuning tool as well with my suspention set-up.

 

as long as i run each tune change in 3's and average it out it should do for me

id just like to know if i am doing better or worse with my tunes im not looking for all out amazing top HP numbers.... well not yet

 

So why is it a POS? what kind of bad experience did you have scottie?

[MaTTSuN]

oh and im going to weight it this weekend there is a truck scale neer my dads place... ive been reading some posts about Z car weight and i hope mine isnt one of those heavy 280z that is over 2800 we will see..

[Scottie-GNZ]

So why is it a POS? what kind of bad experience did you have scottie?

WHOA! Let me correct what I said so there is no belief that I think it is a POS.

 

"Does not matter if the g-tech HP readout is high or low or people think the g-tech is a POS."

 

Hope that clears it up.

[MaTTSuN]

ha thats cool its hard to read the subtext sometimes

i find the its 50/50 with parts on hybridz some likes some dont it depends on how pure your care heart is i guess haha i think im a pure car guy dont like bling and all that just function and form will follow

[Tony D]

Yeah, wanna neat trick with the first-gen G-Tech, watch the instantaneous G-Readout while doing your gear to gear shifts.

 

You can play aorund with shiftpoints and see results immediately.

 

For the price they go for on E-Bay these days, it's worth the paltry $$ to have it around just for that kind of playing. Two of them, and you can see laterals if you make your own bracket...

 

Or pay the $$ and get the PASS system, but I'm cheap. And convinced the SECOND I pay full price for a G-Tech AGAIN, they will come out the NEXT day with the subsequent generation, making mine worth about $40 NIB on E-Bay...like what happened the last time.

[MaTTSuN]

well i wieghed my car its 2766 with me in it 180lbs and over half a tank of gas

not to bad at all i guess my 2800lb guess on my first run was pretty close

i have a few things to adress befor i make anymore runs

id love to get it down to 2500 with me in it