G-Tech Pro RR newbie

[EspenW]

The manual clearly states that you should not launch to soft The most accurat is a firm, but not to hard launch.

Yep, you need to trigger the accelerometer, but that does not take much effort, a normal start is plenty good.

[EspenW]

Now I'm pulling about 0.5g in 2nd gear .

Hmmm.. 0.5G in 2nd...half throttle run?...

[S2central.net]

LOL at you with your fancy smancy RS2 and E85 fuel... I have a mere K24 turbo with 280bhp on tap when I can get decent fuel in the tank. Thats not full boost in 2nd - need a higher gear for that, but then the G force drops

[EspenW]

LOL at you with your fancy smancy RS2 and E85 fuel... I have a mere K24 turbo with 280bhp on tap when I can get decent fuel in the tank. Thats not full boost in 2nd - need a higher gear for that, but then the G force drops

Yep, 0.5G is more than my Golf, though, seeing approx .43G as max in 2nd in that one. The RS2 pulls close to 0.7G in second, but the E50 turbo is far from properly spooled in that gear Not liking the hot summer weather, car feels like a turd these days. 10% power loss vs a cool day.

[Rusty]

Using a weight of 3650lbs 1705Kg I achieved 255 WHP in 2nd and a 0-60 of 5.2

[S2central.net]

255 (two five five) - no way - hp at the wheels ?

Thats 340bhp on the engine using 25% rule of thumb for rolling losses... Or does that old G-Tech you have do things differently. I have a memory it uses the g-readings, vehicle weight and a 15% drivetrain factor to produce its bhp claim... Which for you would be that 255*0.85 for 217 at the wheels divid by 0.75 for 290bhp at the crank.

1705kg is 3760lbs by my maths - that will give you higher figures of course.

The model I have just quotes nett power - it doesn't try to adjust for aero or drivetrain losses... Whats at the wheels is whats important.

All the runs I have done get about 205-215 nhp in 2nd or 3rd... Which matches dyno numbers pretty well.

Paul

[EspenW]

The original G-Tech can be tricked by boost spikes, etc. The new one is in a completely different league, as you can plot graphs. Going from a bleed valve to a ball and spring valve boost controller on my car didn't change peak hp much, but the thing hit peak boost much sooner.. Peak G's in 2nd went from high 0.5's to high 0.6's. This would not show on the original G-Tech.
The old G-tech does not take drivetrain losses into account. Shows net hp at the wheels, just like the newer versions.

[Rusty]

My last RR session dropped 55bhp so I used this as a rough guide (240bhp ATW = 297bhp ATF). 255 is too much but it's not far off so shows that things are working properly. I've yet to get to my test track and do some proper runs. The old clunky G-tech is a bit archaic but it's not too far out.

It would appear to integrate the acceleration to calculate speed and must integrate again to calculate distance for braking.

P=F.v is used to measure power, I'm guessing that F=m.a is uesd, hence the requirement to input mass.

[Rusty]

I'm happy enough with the old clunker, it was afterall cheaper than a RR session and a lot less than a newer one.

[S2central.net]

Alright then - I stand corrected... So I'm seeing 210nhp on the G-Tech Pro RR whilst Andy is on a whopping 255 with the same darn software... Plus a fresh head gasket, 3B fw, opened airbox & exhaust mods plus RS2 IC.

Your dyno numbers of 57bhp losses are quite good. I think I'm mixing up some numbers in my head now...

Your dyno shows drivetrain losses to be approx 25% of what was delivered to wheels but my memory is that I saw 25% drivetrain loss compared to the power quoted at flywheel.

On your method, my 210nhp is approx 263bhp which is maybe about right for shyte fuel I'm using here... Its 95 with a dollup of octane booster in there. So close on 10% drop from known 280bhp reference on 98RON. Bumflaps

[Rusty]

When I can get to my test route I'll do a number of runs and see how repeatable things are and then adjust teh weight to get a repeatable 240bhp, this is what my setup was producing the 3B FW so it should be close. I can also do runs in 3rd to remove a bit of the squat-skew on the accelerometer. I'm happy to be within 10% of the dyno measured WHP, This means that I can now compare setups, chips etc. to give a rough as hell estimate of any gains or losses when combined with the time honoured butt-dyno.

[EspenW]

With the Mr. Dyno I can produce perfectly overlaying graphs on consecutive runs. I use it to adjust cam timing, ignition advance, etc. Real world conditions, so I value it more than any dyno graph.

[magarv]

Yep, you need to trigger the accelerometer, but that does not take much effort, a normal start is plenty good.

Exactly my point and quite obvious that it is to trigger the accelerometer A normal firm start is the most accurat, not to easy and not to hard...

[DJones]

Yep, 0.5G is more than my Golf, though, seeing approx .43G as max in 2nd in that one. The RS2 pulls close to 0.7G in second, but the E50 turbo is far from properly spooled in that gear Not liking the hot summer weather, car feels like a turd these days. 10% power loss vs a cool day.

He.. he.. he.. mine pulls .84g in second and 60 comes up in 4.1. could do it quicker but i need third gear for 60.

[Rusty]

Mine could pull 1g in 6th....



























once

and then 60-0 in 3ft