4722 replies to this topic

[Mopeytitan]

Damn it, had the handling spot on a few days ago but with the steering wheel slightly offset. So I adjusted the rack ends as identically as possible, but now the handling has got worse   Went off to an exhaust fabricators today and collected a load of scrap pipework off him for welding practice. So far I've used up 1/2 a big bottle of gas in the last few months and can only weld 2mm tubes with any sort of consistency. 1.5mm thick tube seems to be considerably harder to weld without blow-through    

Do you have a pedal for your welder? 1.5mm stainless tube shouldn't be that hard... What have you got your welder set to?

[Nev]

Here is my geo sheet, bear in mind I have yet to fix the O/S/R camber when I swap out the ball joints in that corner soon.

 

[Nev]

 

Damn it, had the handling spot on a few days ago but with the steering wheel slightly offset. So I adjusted the rack ends as identically as possible, but now the handling has got worse   Went off to an exhaust fabricators today and collected a load of scrap pipework off him for welding practice. So far I've used up 1/2 a big bottle of gas in the last few months and can only weld 2mm tubes with any sort of consistency. 1.5mm thick tube seems to be considerably harder to weld without blow-through    

Do you have a pedal for your welder? 1.5mm stainless tube shouldn't be that hard... What have you got your welder set to?

 

 

Yep, I've got a pedal, though I haven't been using it. Maybe I should give it a try, thanks for reminding me.

 

I was TIGing with 15 amp base current and 30 amp pulse, about 7 LPM of argon. I'm not back purging and the old exhaust pipes are full of soot deposits from the last owners! LOL

 

 

 

 

[Nev]

Had a bit of a head scratch about a gut feeling I've had for ages about the car feeling like it rear wheel steers in bumps and finally discovered that my rear wheels were toeing in a lot more than I thought. This is probably due to sloppy adjustment on my part (I remember making the adjustment and then not checking with the gauge) when I fiddled with them last time. Anyway, I've reduced the setting and the car is certainly behaving better than before. For a start, it's really noticable how you can hand roll it back and forward with less resistance.

 

I have also reduced front toe in a bit, so far I've had it on 3 different settings in the last 2 days (0 degrees, 0.5 degrees and now 0.2 degrees) , so I can drive it and see what I like best.

 

Dare I say it, but I think it's handling better than I've ever felt before. Am waiting on Mr Apex to test drive on Friday and see what he thinks.

Edited by Nev, 06 April 2016 - 08:16 AM.

[siztenboots]

Go for a tiny bit of front toeout.

[Nev]

Go for a tiny bit of front toeout.

 

Sounds a bit unusual for a road car, what characteristic will that give please, and do we know whos done that on their (road) cars?

 

Might give it a go just the feel the effects, but am a little hesitant to increase the scrub on the fronts when the camber is already moderatly accute (for road driving anyway).

Edited by Nev, 06 April 2016 - 07:16 PM.

[Matthew Bentley Racing Ltd]

Every single car irrelevant of use that comes out my workshop have toe out on the front.

[cookster501]

Just out of interest how much toe out would you recommend to run on the front with 17" wheels?

[Nev]

Every single car irrelevant of use that comes out my workshop have toe out on the front.

 

Thanks Matt, I will get in the garage today and add a bit and see what it does.  

Edited by Nev, 07 April 2016 - 07:26 AM.

[Nev]

Looking at the toe out settings here http://wiki.seloc.org/a/Geo_Setups it seems the toe out on the front has to be microscopic, not sure I can manage to get that setting with any accuracy, but will try.

[Nev]

LOL, it took me 3 goes of jacking the car up, adjusting and re-measuring, but managed to set it up with "about" 0.05 degrees of front toe out. This is more or less the tiniest amount that I could visually see/measure down the eyepiece of the gauge.

 

It raining so I can't subjectively test the car yet; fingers crossed for a dry afternoon, as naturally I am keen to see what it feels like.

Edited by Nev, 07 April 2016 - 10:33 AM.

[siztenboots]

measured on the rims , its about 0.5mm difference between the rim faces to the parallel string , 16" the difference is less for same angle.

[The Batman]

You still want 2 Na boxes?

[Doctor Ed]

you ever raced/driven/tuned a kart Nev?

 

an absolute ton of setup experience to be gained playing with those things

[Nev]

You still want 2 Na boxes?

 

No thanks, the 2 I've got seem to be working ok without restriction. I used a magenhelic gauge on the inlet track at 7000 RPM and there was no measurable pressure drop, so all is good.

 

Thanks for remembering

[Ali87]

Only 40 days till Hoon, still time to sign up...

[Nev]

you ever raced/driven/tuned a kart Nev?

 

an absolute ton of setup experience to be gained playing with those things

 

No, though I have thought of it (mainly in the past before I got Nipper). I can imagine there is a loads you can do.

 

I do sometimes support a Global GT1 owner which is semi-kart like (only 370 KG with fluids), though I've no idea of it's geo setup.

 

I've done a lot of fiddling with the geo on mine over the last 3 or so years. Even went out with someone this evening and swapped cars for some advice, he think my front rebound is poor, which is dead right as one of my nearly new Nitrons spat it's oil out about 3 months ago. I've been putting off sending it off for yet another refub, as it would mean the car will be off the road for a week at least.

 

I'm still learning about geoing - it's a real black art, on my car so much is different too. Experimentation helps hugely, but it does take ages, as I'm sure you know when you change one thing it often affects another. I've spent about 15 hours in the last 2 weeks fiddling with mine and it's currently worse than it was 4 days ago !

 

 

 

 

[Nev]

Only 40 days till Hoon, still time to sign up...

 

Yep, I have to say I might come as I am back in the country, lets see what the weather throws up and I'll make a last minute decission. I can always bring my tent and sleep bag as I love rough camping.

Edited by Nev, 08 April 2016 - 07:30 PM.

[Doctor Ed]

I only mention it as with karts, all the little changes make profound differences, and you can literally learn lap for lap what this or that does. Then it take 5mins to change, and you can test it back to back. Gives you a very rapid appreciation of what to expect with changes, and how to correct certain behaviors

[Mr Apex]

I drove Nipper at low and medium speeds today on a range of different surfaces. The car feels light and precise on smooth surfaces, it rides generally well, but as soon as it hits sharp bumps, it kicks off them, with no rebound damping. It feels like bump steer on rebound, rather than on compression, which is a weird sensation. There is also instability as the brakes are released. My car feels softer and is much easier to drive. I have less grip and more roll, but over undulating surfaces, my car feels much more settled.

I got back in my car after driving Nipper and nearly put my clutch pedal through the floor. Nipper has a seriously heavy clutch!

The engines couldn't be more different. Mine is SC stage 2 and running a 2.5" Tullett system. It is linear and smooth. Nipper chatters and pops and bangs at low revs, needs about 3K to wake up, then it is serious hammer time. 

Nev - you need to fix that damper, then get Nipper on a fast, undulating track.