An Odyssey of Tuning a Big Power VX220
Discussion
nevcontractor said:
robinessex said:
Quote:-
Since the last update I've stuck some uprights on it (to help with lowering it's COG)
How does that work then?
You can do that to adjust the roll centre, but it ain't going do anything to the COG
The uprights I installed raise the hub location by 40mm, this in turn allows me to lower the car by the same amount without affecting the geometry of the wishbones. So in summary, the car is now 4cm lower with corresponding lower CoG.Since the last update I've stuck some uprights on it (to help with lowering it's COG)
How does that work then?
You can do that to adjust the roll centre, but it ain't going do anything to the COG
Edited by nevcontractor on Friday 13th March 15:21
robinessex said:
Er, hubs up 40mm, car down by 4cm, happens to be 40mm-4cm=0.0. No change of COG height there then.
If the hubs are located 40mm further up on the uprights, then this means a 40mm drop with no changes to any suspension geometry. The COG w.r.t the roll centre obviously won't move much, since both have moved in the same direction. The COG w.r.t to the tyre contact patches clearly will have been lowered.
robinessex said:
Er, hubs up 40mm, car down by 4cm, happens to be 40mm-4cm=0.0. No change of COG height there then.
Maybe I didn't explain well enough. The OEM car with OEM hubs rides at 140 mm above the tarmac. My car (due to the hubs) now runs at around 100mm above the tarmac. Thus the CoG is lower.Hadn't seen this topic the first time round 
I had a K series Elise tuned to 200hp and that wasn't slow by any means The good thing about the K series is that it encouraged you to drive it hard, all the power was at the top of revs so the right gear at the right time was critical. I've now got a 400hp TVR (offical figures so subject to some leeway) and I've never found myself thinking, you know what this needs? More power!
Looks good - boxy, but good
I had a K series Elise tuned to 200hp and that wasn't slow by any means
The good thing about the K series is that it encouraged you to drive it hard, all the power was at the top of revs so the right gear at the right time was critical. I've now got a 400hp TVR (offical figures so subject to some leeway) and I've never found myself thinking, you know what this needs? More power! Looks good - boxy, but good
Blimey, I haven't updated this thread for ages, so...
The ECU is in now with 2 maps, one for minimum boost (11 PSI) and one for 25 PSI, I can hot-swap between them with a switch on the dash and re-program things anywhere between those 2 settings with an on board laptop. I restricted max boost to just 25 PSI as I was finding the car too hard to control at 31 PSI with 500 ft/lb and 550 BHP previously, it is now quite a bit more subdued and probably a faster drive on an average road as a result.
I have also machined up some bespoke parts to fit some Brembo 4 pots on the front of the car which now have RC6 pads though front Bias is too much ATM. I may remedy this with a similar rear setup and a bias controller. I used Alfa 159 28mm x 330mm discs (which just cost £15 on eBay!) and Porsche GT2/GT3 calipers (quite cheap too).
I have also installed some (very expensive!) uprights which raise the hubs up 4cm (which helps handling when lowered), followed by a very intensive geo setup by myself over 2 weeks, with literally dozens of tweaks and fine tuning each followed by a test run. The car now really handles like it never has, other VX220 owners who have driven it say it has more grip and "security" than their own cars.
I've had a few minor bugs, a melted water pipe (easily fixed), burnt out GT3 flange gaskets (and a snapped flange bolt), wheel rubbing issues (fixed with spacers) etc, knackered wheel bearing and 1 weeping coil-over. Overall however, the car has been nice and reliable for 1.5 years now.
Old calipers vs the new ones:
Low power map (super smooth and linear power delivery):
High power map (extra mid range for making Porche/Lambo/Ferarri owners cry):
Dummying up:
Machineing the dummy:
The final look:
The car gets USED (it ain't no garage queen)!
My fave blast run, 160 mile circuit in the Black Mountains at dawn, with almost no other cars on the road, faster than most tracks ;o)
Geo'ed up, old skool style with penty of testing:
Tyre expenditure requires it's own bank account:
Another magazine article:
The ECU is in now with 2 maps, one for minimum boost (11 PSI) and one for 25 PSI, I can hot-swap between them with a switch on the dash and re-program things anywhere between those 2 settings with an on board laptop. I restricted max boost to just 25 PSI as I was finding the car too hard to control at 31 PSI with 500 ft/lb and 550 BHP previously, it is now quite a bit more subdued and probably a faster drive on an average road as a result.
I have also machined up some bespoke parts to fit some Brembo 4 pots on the front of the car which now have RC6 pads though front Bias is too much ATM. I may remedy this with a similar rear setup and a bias controller. I used Alfa 159 28mm x 330mm discs (which just cost £15 on eBay!) and Porsche GT2/GT3 calipers (quite cheap too).
I have also installed some (very expensive!) uprights which raise the hubs up 4cm (which helps handling when lowered), followed by a very intensive geo setup by myself over 2 weeks, with literally dozens of tweaks and fine tuning each followed by a test run. The car now really handles like it never has, other VX220 owners who have driven it say it has more grip and "security" than their own cars.
I've had a few minor bugs, a melted water pipe (easily fixed), burnt out GT3 flange gaskets (and a snapped flange bolt), wheel rubbing issues (fixed with spacers) etc, knackered wheel bearing and 1 weeping coil-over. Overall however, the car has been nice and reliable for 1.5 years now.
Old calipers vs the new ones:
Low power map (super smooth and linear power delivery):
High power map (extra mid range for making Porche/Lambo/Ferarri owners cry):
Dummying up:
Machineing the dummy:
The final look:
The car gets USED (it ain't no garage queen)!
My fave blast run, 160 mile circuit in the Black Mountains at dawn, with almost no other cars on the road, faster than most tracks ;o)
Geo'ed up, old skool style with penty of testing:
Tyre expenditure requires it's own bank account:
Another magazine article:
Do not ever, no, don't do it, pack it in, stop it, washing bits in PETROL. It's awful stuff, the fumes are VERY BAD, and you might blow yourself up. Use either a water soluble stuff, or White Spirit. Still don't breath in those fumes though. I made a wash tank from a very large plastic box, nice and strong, £10 from high street shop. Made a wire shelf from an old oven shelf that sits about 3" from the bottom. Put a drain tap in it. To use, fill with WATER until it's just below the shelf. Top up with WHITE SPIRIT. When you clean things, a lot of the crude will drop into the water, and keep the White Spirit much cleaner. Occasionally drain of the yucky water, and refill. When stuff is clean, pop along to a local guy who can blast all the steel bits, and Aqua blast the ali bits. http://www.aquablast.co.uk/ The you can choose how to paint the steel bits, some like to powder coat, others a 2 pack epoxy. The ali bit look real cool if you have them anodised. I use these guys, not local to you I know, but good. http://ctc-powder-coating.co.uk/
RemyMartin said:
Looks like a bloody awful mess! But I'm sure it's a riot to drive
Ha ha, yes it's not many people's cup of tea, messy, VERY noisy, smelly, brash and visceral. Anyone who even slightly thinks of his car as a piece of jewelery won't like it. If you like going faster than almost anything else around then you'd like it.
Another year has passed by, this year's niggles have been:
1/ Build a new exhaust silencer for it as the old one got too hot and cracked and made the steel too brittle to weld up.
2/ Made a new PCV swirl pot that drains back into the sump which has helped reduce emissions.
3/ Bought some new (second hand) front wheels that are 1" less radius and take a 20mm narrower tyre. This has helped make the front end better mannered on the bumpy country roads I tend to drive on .
4/ Discovered the cam cover has melted and warped, so this is currently being replaced, along with a new thermostat.
5/ Decided to stiffen up an engine mount (by pouring some PU into the existing one).
Other than that it's been reliable and fun, just pour in the petrol and go.
1/ Build a new exhaust silencer for it as the old one got too hot and cracked and made the steel too brittle to weld up.
2/ Made a new PCV swirl pot that drains back into the sump which has helped reduce emissions.
3/ Bought some new (second hand) front wheels that are 1" less radius and take a 20mm narrower tyre. This has helped make the front end better mannered on the bumpy country roads I tend to drive on .
4/ Discovered the cam cover has melted and warped, so this is currently being replaced, along with a new thermostat.
5/ Decided to stiffen up an engine mount (by pouring some PU into the existing one).
Other than that it's been reliable and fun, just pour in the petrol and go.
Edited by nevcontractor on Saturday 24th March 11:51
Gassing Station | Readers' Cars | Top of Page | What's New | My Stuff