More work on the little black GTI...

I've left it on the axle stands:



Because tomorrow, I'll be fitting this little device:

what is it? :dontknow:

speed sensor for the lm1?

bens_cab said

speed sensor for the lm1?

Got it in one!

I thought it was an audio lead, gotta have tunes  :mrgreen:

god im good

this should give
you some good info with the lm1 get those datalogs done  :wink:

bens_cab said

god im good

this should give
you some good info with the lm1 get those datalogs done  :wink:

Yeah, I can then check clutch slip %, maybe there's a little bit of time to come from a harder clutch? It would just be nice to have the speed in mph on the logs too. I can always correlate it against the timing slips if needs be.

One of the speed sensors is now fitted, and I also took the car for a test run (down a handy local private road, nearby) to check out the new gearbox, lightened flywheel and electronic gizmos.

You can definitely feel the lower gearing. On the way home (once fully warmed up) I can pretty much ignore 1st and out-accelerate other cars even starting in 2nd. Also if you put your foot down, the revs really jump up, so this must be the effect of the lightened flywheel.

This is the best log I recorded (shows the most useful stuff):



As can be seen (by looking at MAP, dark blue line) it was a very slow start in 1st, to avoid any kind of wheelspin. Also it was a curved start rather than a straight line, so the log goes from 1mph and the real acceleration starts around 0.7 secs in. Then I got a bunch of wheelspin once I changed into 2nd (the arrow indicates this) which I wasn't expecting, so I had to come off the throttle again.

3rd gear went better. Once I was in 4th, for some strange reason (which I need to fix) the datalogger couldn't record a speed more than about 80mph, so I need to look into this (possibly recalibrate things). But I can work out off the graph that at 7000rpm (approx where the limiter comes in) I'll be doing 98mph. So it should see me (just about) to the end of a 1/4 mile strip.

Also the digits on the right show the point in time selected by the cursor, in this case I put it as near to 60mph as possible. Taking into account the approx 0.7 sec before the start of acceleration, it shows 6.88 - 0.7 = 6.18 secs 0-60.

ooh pretty graph!!

 

i kind of understand it!

each line is a gear? x is time and y is revs?

pauls been playing with the ectha sketch again :mrgreen:

rov716y said

ooh pretty graph!!

 

i kind of understand it!

each line is a gear? x is time and y is revs?

No, each line is a parameter, and time (in seconds) is along the bottom. The parameters are: speed (mph), engine speed (revs/min), MAP (Manifold absolute pressure, ie how open the throttle is) (bar), AFR (air/fuel ratio)

oh i get it now lol!

you know when you look at those pictures hiding another picture. like on of them but i can actually see it!

so 10 sec to 80mph not to shabby paul!  prob a bit (lot) better than the gtd lol

but once i had a chance to do some more bits to her and fit the bigger turbo we'll see muhahaha

Just reviewing the logs, here's a more typical scenario, tootling through a suburban area:



You can see the gentle acceleration through 2nd –> 5th, and the much lower (only goes to about 0.7 bar) MAP and the AFR staying at around 15.5-16.0 (probably due to the 16V WUR which has a vacuum input and richens the mixture only on acceleration, eg high MAP).

This is the run at Inters 2008 which resulted in 0-60 in 5.5secs and 1/4 mile in 14.34 secs:



Even then, you can see areas I can improve. There's some kind of blip in 1st gear, probably due to not having traction in the 1st second or so, until the tyres 'hooked'. Then there's a good deal of wheelspin on engaging 2nd gear. So, without these things (ie at a better track) I should easily be able pick up another couple of tenths, whether I can break into a 13 second time, I don't know?  :dontknow:  But I'll find out in about a week's time at Santa Pod.

As many will know, I had mixed success at the Retro Car show at Santa Pod last weekend. On one hand, I won my class (A, under 2000cc non-boosted), beating many Ford, British Leyland stuff, etc. But I also broke my gearbox, the problems compounded when the AA felt like they'd not bother recovering me home either.

Here's some pics from the show (with thanks to Lawsy):











Anyway, with massive thanks to Rajan, the car is home now.

So the past week I have been busy scouring eBay and I've bought another FD code gearbox (bargain ?31) and also this:



so that I can at least stand a fighting chance of getting the car home next meet!

This week (in the evenings after work) I'll be swapping the 'box, at the moment its soaking in degreaser since it needs a good old clean.

And you will be pulling that with ?

 

chudd said

And you will be pulling that with ?

 

Another car?

your officially a trailer queen now haha

paul_c said

chudd said

And you will be pulling that with ?

 

Another car?

A Golf ?