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I'll try the pulls and monitor the MAF readings. I don't have pics of the 02 sensors placement. But I did research on the forum before the install. STR members with good results recommended 2" before the cats and 2"after. These cats are shorter in length than the original.
I would really like to meet up with my local Jag brothers in tampa. Who are they? I know rinzo lives here. Will be meeting up with him for the first time tomorrow night for a car meet.
I don't know anything about the trans in your car (too modern for me!). Is it a 5 speed auto? Six speed auto? What gear are you in going thru the traps?
On some cars I've driven the shift to 4th, 5th, and 6th can be like falling off a cliff....dropping you well below your power band, perhaps near the end of your run. That would hurt.
In the lower gears where does the trans shift at WOT? Is it shifting too soon? It matters!
OTOH...shifting too late can hurt your ET as well. I had an Olds 442 that ran 14.60s @ 99.99 mph shifting @ 4400 RPM and 14.80s @ 97 mph shifting @ 4800 rpm. The way the engine was cammed it actually lost a lot power over 4500 rpm....and the way it was geared I passed thru the traps right at 4400 rpm. It worked out !
Anyhow, I'm not drag race authority (or any other kind of authority for that matter) but I think any discussion of 1/4 mile ETs and speed must necessarily include power band and shift points.
Thanks for the follow up Cam and my fellow Jag lovers. I'll update on the status of the cat and hopefully find a tuner. This was my first time at the strip. Hopefully next time I'll do a little better.
I remember my first time. My pal, riding shotgun, was heckling me so badly that I made umpteen mistakes....which, of course, exactly what he intended
With a bit more experience...and no badgering..... I became more comfortable and could begin experimenting with different techniques. It's very satisfying when you watch your ETs drop thru noting more than practice and experimenting.
Years ago I had a Mustang GT (fun car!) which I took to the strip right after buying it. First run was 16.66 @85 mph. By the end of the night I was well into the 14s just by becoming familiar with the car, adjusting shift points, and trying different launch techniques.
NICE cambo . you are extremely close to your 12.99 target .
did i notice a new kitty in your collection ?
jazzyjags
after reading it rained when you got there . id say humidity may be the problem with top end power.
i also wonder if you cleaned out your charge coolers whilst the blower was off.
they tend to fill with crap.
i was going to jump in and say blocked cats , but i see you've been there done that . and that put mine back in the low-mid 13's . so I'm going to go with weather conditions theory .
Thanks for the follow up Cam and my fellow Jag lovers. I'll update on the status of the cat and hopefully find a tuner. This was my first time at the strip. Hopefully next time I'll do a little better.
Here's a video of 13.25 @ 105.45mph in my XJR at Santa Pod in the UK, maybe have a listen to the way it goes through the gears, see if it "sounds" like yours.
Jazzyjags, you seem down on power for the mods done. Have you ever had it on a dyno?
Cambo, it seems with the tune you gained ~2mph/20hp which is impressive. Have you and your man cracked how to flash the STRs/X350 XJRs yet without removing the ECU?
I've had no gearbox problems on my STR which is just shy of 80k and I've not heard of others with twin screws and the 6HP26 to have broken anything either.
I have not dyno'd yet. Will try to do so within the next 2 weeks or so.
Cam my 3rd gear sounds a little lazy compared to yours. Im driving my sons G35 and keeping the cat in the garage until the car show tonight. Afterwards I'll do a couple pulls and monitor the MAF readings in various gears and we'll see what I got.
Cambo, it seems with the tune you gained ~2mph/20hp which is impressive. Have you and your man cracked how to flash the STRs/X350 XJRs yet without removing the ECU?
I was hoping for 12.99 and more mph though...
Yes tunes in 2003-2005 XJR and STR flashed over the OBD port, no need to remove the ECU from the car.
Originally Posted by JagSTR2004
I've had no gearbox problems on my STR which is just shy of 80k and I've not heard of others with twin screws and the 6HP26 to have broken anything either.
Nothing is "broken" in mine it's just worn out. The issue is the main clutch pack wearing out, put too much torque through it (by raising the torque limiter in the tune) and it flares the shift 3-4 and slips a bit & I get a P0783 code and trans limp mode. Put the torque limiter back to stock and it drives ok. But as I said 118'000miles on mine, so it's getting up there...
I've spoken with a ZF specialist here in Australia (Nizpro) about getting a rebuild, and when i described the problem to him he said "yep, it's worn out"
I think the issue for me is that I bought the car with 91'500 miles on it, and for sure it had never had a trans fluid change, I changed the fluid not long after I bought it, but it was probably too late...
Originally Posted by jazzyjags
Cam my 3rd gear sounds a little lazy compared to yours.
I have a feeling you've got something else in the pipeline that'll be substantially faster than that though!
Let me know if you have a contact over here that can flash mine, I feel like the torque limiter is still holding me back a bit and well, you can never have enough power eh?
02-24-2017, 08:34 PM
