So the muffler shop said for my car the thing to do would be the res delete with X pipe. I’d gain a few HP but more importantly I’d stave of any loss of power at full throttle. Well another guy told me he did that’s on his 02&05 and the low end torque fell flat on its face on take of but he did a mid and center muffler delete. A little more work then what I’m doing. What do you guys think of the delete with the X Pipe ? I’m at the 665hp now With all the bolt ins now. Let me know what you think. He said this is a great place to start and it’s easily replaceable if you want to go back to stock. JJ

 

Do you have a Dyno chart showing your power?
Mine put 530HP/540 TQ to the wheels on the Dyno.
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No. I’m talking about the exhaust options. Why are you only at 540? What year is your XJR ?

 

I have a xpipe/downpipes (cats delete) on mine supersport, no issues with a low rpm torque, still way too much to avoid a wheelspin.

 

oh I didn’t notice you said to the wheels. Gotcha. Supposed to have mine dynoed Wednesday we will see.

 

do you have an idea of what your total initial HP is ? What car do you have and what have all upgrades have you done ?

 

I ripped out the stock center resonators and replaced with x-pipe and resonated x-pipe (the resonated x-pipe was to knock down the drone from the Borla rear mufflers). No loss of torque or power.

 

Great to hear and post back your dyno chart if possible. We don't have many for the XJ.
I can guess the HP at the flywheel but you have to estimate drive train losses and they are a range of numbers posted.

Here is my dyno thread with pictures;
Dyno Run

Here is a stock 2016 XJR;
2016 Stock XJR
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Didn't had a time yet to do a dyno, but im trapping 1/4mile at 197.71kph (121.3mph) on a public road (on a track i think ill be faster) on mine long Supersport (Denso ECM and 6hp28), with a full tank, 125kg driver and lots of junk in a trunk

 

I have not done the 1/4 mile yet either and want to. But I am still practicing the launch and have been following the F-Type guys. I see low to mid 10's in the 1/4 mile so I know they are putting down some serious power!
But that AWD just plain kicks butt in the traction department.

That's a good 1/4 mile speed. I hit 120.6 on the track at the 1/4 at the Texas mile. Hot day as it was 97F too.
I am hoping for low 12's and and outside chance of maybe a high 11 in the 1/4. Afraid it will all depend on me getting the car off the line correctly. The car can do it if I can figure out the right launch technique!

Did you see that VAP now has a tune for the 8 speed ZF? Have not heard of anyone running it.
Don't know exactly what it will do because the transmission is very good as it is?
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Well, F-type is a bit diffrent car. AWD, plus diffrent rear diff ratio (2.56 XJ vs 3.31 F-type), so they putting more power to the wheels.
This particular run was made on a Triangle TH201 tyres, if ill put semi-slicks on, new air filters and a skinny driver (lol) it - it would be 11sec. Not to mention that the traction on a drag strip is way better than on the public road, where im testing
I've seen, but not intrested tbh (im runnin 6hp28 and slowly developing mine own tune for it). But i'd be very cautios with a trans tunes, i do know cases when a tune killed a transmission (and it's as easy as 1-2-3).