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2008 4.2xkr tuned vs 2011 5.0xkr with pulley 0-60
prediction for outcome?
Will be testing on same street , similar weather conditions and similar launch technique
Both cars have good summer tires 285 width
Results: to my surprise I was not able to get a better time than a 4.5 0-60 on the 5.0xkr, other runs were 4.6- 4-7 range , I was not able to launch completely spin free but pretty close on the 4.5 run.
So far older Xkr wins as I can get 4.2sec and as low as 4 flat with a perfect launch with hardly any wheel spin.
Next,: tuned 5.0xkr results, although I suspect traction will be an issue if we add more power.
(Note: if we are using a 1ft rollout for 0-60 as they do in magazines, above 0-60 times will be slightly faster by around .25 of a second)
If the 5.0L only has a pulley, but no tune (as you state), you could possibly be running less HP than a stock 5.0L.
The 5.0L needs a tune to get the most out of the pulley mod.
I have to agree, mine has a smaller upper pulley, modified exhaust (no backbox), K&N's and dyno'd it was just putting out 493, so some horses had escaped!
That said it's plenty powerful enough for me, although I do have a chattering SC nose coupler, which may result in the power being down. I'd not consider a tune until the nose coupler is done and the tranny has a fluid change. That said my local indy who will be doing the coupler races Jags (Swallows Jaguar) can't wait to tune mine as feel that can easily get 600bhp out of it without any many more mods. The question do I want one?
Just have to correct you guys on the pulley. Smaller upper pulley upgrade will not cause a power loss. You will actually gain some at low to mid rpm range until stock boost levels are reached That's when ECU will keep it at near stock levels. So you will gain boost at low to mid RPMs. ECU tune (proper one) will actually unlock and remove the limiters which are there to keep stock boost in check.
I'm I'm not surprised by the numbers as a stock XKRS manages the best of 4.26 compared to my 4.2xkr at 4.05
Yep, tyres can and do make a yuge difference.
With crappy P-Zeros (code name for Zero traction!) or Dunlop SportMaxx (AKA Dunslips) on the rear the tyres will spin spin spin and/or the DSC will cut the power, resulting in a very poor launch.
But with Michelin Pilot Sport 4S instead the car will simply grip and go.
Yep, tyres can and do make a yuge difference.
With crappy P-Zeros (code name for Zero traction!) or Dunlop SportMaxx (AKA Dunslips) on the rear the tyres will spin spin spin and/or the DSC will cut the power, resulting in a very poor launch.
But with Michelin Pilot Sport 4S instead the car will simply grip and go.
Ps4s cant get grip too ( lots of spin, nor much acceleration, they're starting to grip after 120-130kph.
Just have to correct you guys on the pulley. Smaller upper pulley upgrade will not cause a power loss. You will actually gain some at low to mid rpm range until stock boost levels are reached
Apologies then Alex
So would my rattling nose coupler be robbing me of 17 horses, or would my standard tune with no backbox be responsible?
Ps4s cant get grip too ( lots of spin, nor much acceleration, they're starting to grip after 120-130kph.
Surely temps and atmospheric conditions play a part?
For example the average annual temp in Moscow is 43f where (for example in San Diego it's 20f degrees warmer on average (even more in some other US locations).
I know my PS4S's work better on hot days here in the UK...or seems to feel that way to me.
Surely temps and atmospheric conditions play a part?
For example the average annual temp in Moscow is 43f where (for example in San Diego it's 20f degrees warmer on average (even more in some other US locations).
I know my PS4S's work better on hot days here in the UK...or seems to feel that way to me.
They're still spinning at 70+ F, its summer here however while the car was in stock they had decent grip.
well, anyway 0-100 is an indication for a slow)underpowered cars only. For anything greater than 450fwhp the 100-200, 0-200 or a 1/4 are only decent measures.
Surely temps and atmospheric conditions play a part?
For example the average annual temp in Moscow is 43f where (for example in San Diego it's 20f degrees warmer on average (even more in some other US locations).
I know my PS4S's work better on hot days here in the UK...or seems to feel that way to me.
Both cars, my car and customers tested have good summer still tires. Mine has PS4 , customers has Goodyear F1 ( will. Have to double check)
They're still spinning at 70+ F, its summer here however while the car was in stock they had decent grip.
well, anyway 0-100 is an indication for a slow)underpowered cars only. For anything greater than 450fwhp the 100-200, 0-200 or a 1/4 are only decent measures.
I think there is a point where rear wheel drive cars actually become slower with added power at 0-60 , all wheel drive or racing slicks needed .
Ps4s cant get grip too ( lots of spin, nor much acceleration, they're starting to grip after 120-130kph.
You can't just mash accelerator pedal from a dead stop. Michelin Pilot 4S will offer more grip but it is still possible to overwhelm traction and spin tires. I still loose traction with my F-type, and I also have LSD.
You can't just mash accelerator pedal from a dead stop. Michelin Pilot 4S will offer more grip but it is still possible to overwhelm traction and spin tires. I still loose traction with my F-type, and I also have LSD.
I know. But ive had spin last week when shifting at WOT from 3rd to 4th gear at 150kph. Its not mashing from a dead spot...
4.2xkr tuned vs 5.0xkr with pulley 0-60
however while the car was in stock they had decent grip.
2008 XKR Convertible, (mods: AlphaJagTuning ECU Tune , 1.5lb pulley, (200cel cats( are now melted), xpipe, Bosch 001 pump, 180 Thermostat.
