Monday, February 06, 2012 - 07:31 pm, by: Shane Haverkamp(Havabeer)
hi everyone, i recently did a a 5 speed conversion and a torsen diff swap on my TT. my problem is, my speedo is now reading close to 10% out. I've yet to try it exactly with my GPS but driving along side gf's brand new lancer going about a 100 my speedo was showing 110
the current rims i have on the car are 9.5 x 17" with 265 45 R17 on them and i'm up for some new tyres so i'm hoping i can get some different sized tyres to fix the problem.
now my questions are: 1. a tyre size calculator is saying i need to go to a 55 or 60 sized rim to get the speedo to show 7.9% and 11.9% slower on my speedo. is this correct
2. how can i go with stretching a smaller sized tyre on there. like a 235 seems to be a more common and "cheaper" size.
3. is there anything else i can look at to change my speedo, i thought i recall a mate saying something about a jaycar thing that can alter the speedo input electronically somehow.
Monday, February 06, 2012 - 09:54 pm, by: Aaron Casey(Blownminiturbo)
Apexi rsm, wires into your speed input to ecu. Allows you to change ratio to compensate for either different wheels, diff ratio etc. also has a speedo over 180km/hr and can de-speed limit car. If you get g sensor can do 1/4 times, 0-100km/hr, much more. Are you sure the diff ratio is 4.08? Take the back off the diff and count teeth.
Tuesday, February 07, 2012 - 08:42 am, by: Aaron Casey(Blownminiturbo)
They will fit stretched. You would be better off selling if its 3.9 as will kill acceleration and fuel economy as more load on engine as labouring it. And use the money to get correct ratio
Tuesday, February 07, 2012 - 11:52 am, by: Shane Haverkamp(Havabeer)
ok maybe i have it wrong aaron as the car seems to accellerate quicker in my opinion, wont know till i count the teeth, i'll try and get that done over the next few days
Tuesday, February 07, 2012 - 12:56 pm, by: Aaron Casey(Blownminiturbo)
Hmm interesting.. I think out of memory there was a 4.3 option in something that wasnt a soarer but cant remember. You count the teeth on the crown wheel, eg 49. And pinion teeth eg 12, divide the crown by the pinion 49/12= 4.083