I'm waiting on the return of my blower with the Snake Bite mods and am
thinking ahead to taking a trip to the San Antonio Raceway drag strip to
test the mods.

One of the things that is detrimental to this type of test is the anti-spin
controls on the STR. This may be synonymous with DSC, I simply am not
sure, but maybe one of you techies could educate me.

I want to be able to temporarily defeat the anti-spin control in order to be
able to take off from the start line witout the engine bogging down until
traction is regained as it will be severely detrimental to the elapsed time
measurement.

Can you help ?

 

Just turn off the DSC (see handbook). I think it may still activate in some circumstances but probably not from the start line. You'll probably wish you had an LSD.

 

There is the DSC button next to the shifter below the stereo. Click that and you will see on your screen that the DSC has been disabled. You will be to spin the tires at will.

Make sure that you show pics and post results!

 

FYI dont our s-types use the 8.8 Ford pumpkin whats the spline count? I wonder if the Ford racing LSD I was going to put in my Mark VIII will fit in the str.

 

Even if the DSC is set to the off position the DSC will intermittantly kick-in when sensing "excessive" wheel spin. In other words...slam the pedal down, the wheels will spin till they smoke...for a short while that is, because the DSC though initially disabled by the operator, still monitors conditions putting an end to this behavior (you'll notice the amber DSC light rapidly blinking on the dash). Jag worked hard engineering-in both mechanical and personal safety measures. I'd love to be able to disable the DSC along with a LSD!
I've read the differential is 8.8 inches, 28 or 31 splines? I bet one of us can confirm ring and pinion dimensions along with spline count via Jag. Who's up to it?

 

Have you run at the strip before so you can compare your times?

 

I've never officially run my STR. Go to DragTimes.com you will find 5 STR's that ran official times. The fastest was a stock 05. He ran a 13.1 1/4 mile at 105 mph. Outside temp. was 45 degrees. See what a nice cool day does for an engine? Dense O2 in low temp. high pressure atmosphere. IMHO, a well versed driver can put a stock STR through a high 12 second 1/4 mile when as closest to sea level on a cool day. Ya-all may have noticed from a stop, a graduated depression of the gas instead of a sharp stab to the floor yields a bog-less spin free start yielding quicker 0-60 and 1/4 mile.

 

Do bad things (MIL, RP, whatever) happen if you remove the DSC's power? Just thinking of another way to keep it off. Disconnecting wheel sensors might also do it.

There's some sort of dyno here but don't know if it's what you guys expect (I don't see temp or baro):
http://www.jaguarforum.co.uk/viewtop...31478&start=30

 

Am with bfsgross here, the more sudden power gets delivered the sooner a wheel will break out. DSC can still be of help, as when you apply the power carefully, and one wheel starts to spin slowly, the ECU will try to apply the brake first, sort of like a cheaps man LSD ;-). Anyhow, when the power isn’t too much during this small correction, the wheel should get traction again. If not, or when the braking doesn’t help the ECU will be more radical in lowering the power to the wheels by reducing engine power, but then you have lost the startup as (at least with my pre-historic tracts) the ECU will bring the power back again to abruptly and the whole circus above starts again, this can continue in 2nd gear.
If no lsd, then try to get better/wider tires, I think the Stype I have worked on has 275 wide toyo tires, not so bad in traction, but to noisy imo.
330-340 whp is about normal for a good working STR and on this particulat dyno type (1 large drum rollers). The graph does say it is DIN corrected, which means pressure and air temp have been taken into consideration.

 

yup, run it at the strip. I wasn't able to baseline mine so I'm bummed. One thing that is interesting is that at the shop yesterday when i was having the codes pulled, it said lean in both banks. I'm not sure if this is from when after I installed the blower or if it was from before. I'd have to believe it's from after though since the fuel system on these cars has a decent amount of headroom. So, if it is from after, this thing is moving some air and the motor is trying hard to fuel it.

I'm going to install alcohol injection to fight the discharge temps and fueling. Let me know how yours turns out. I'm happy so far!

 

well Ford racing has the LSD for both, I have the 28 spline version since the M8 was a spline count.
Mustang Cobras with IRS use the 31 spline count

 

I have a the feeling Jag used 28 splines on the STR.

 

hmmmm looks like I may crack into the pumpkin.

 

When I turn off the traction control, it seems like it is completely off, I smoked a tire half way down the track once...stupid non lsd bull****

 

I thought LSD was a psychedelic drug ? :-) What is it ?

 

Lysergic acid diethylamide aka LSD
LSD aka Limited Slip Differential

 

budsang. I don't know how your STR smoked the tire all the way down the track. Perhaps you managed a decent launch spinning the tire spun fast enough so that the DSC considered it normal wheel revolutions? Jaguar explained to me what I posted earlier because I noticed DSC intermittantly kicking in though I disabled it. ???

 

When I turn it off, it is off. I've smoked my tires on numerous occasions without it kicking in...

 

OHHH????? Hmmmmm.

 

Maybe it's a software change and some cars don't have it?

Bob S.