Hallo !

I m new here and i have some questions for tuning my xjr6.
Please forgive me for my bad english i come from Austria
I already have installed a cold air intake, Andys brackets and custom dual exhaust system. I tested the jag on the dyno and it only had 280hp on the rearwheels, so i tested the loading pressure from the supercharger an it only loads 0,4bar and at higher rpm it falls down.


Now i have remanufactured and ported the SC and also bought a bigger lower pulley and i also will have a look at the bypass valve maybe there is the failure for the low pressure ??

And i also want to install a bigger throttle body, anyone did that before ? Andy Stodart told me that the engine is running rich enough no ecu remapping has to be done, i that correct ?

Thanks for your Help and Informations !

Greetings from AUSTRIA

 

Hi Austria


There is some good info about bigger throttle bodies in this thread; https://www.jaguarforums.com/forum/x...adapter-78096/


Seems like itīs possible to bore it out from the stock 72mm? to about 80mm and, of course, also have a matching blade made. If instead using some aftermarket tb you will have to arrange something different for the idle control.


I personally doubt that there is much gain with a bigger tb alone. Both the tb-adaptor and the air ducts have too much of knicks and bends. The square area in some sections are probably even insuffient with the stock tb. I have spent several hours on mine with files and sand paper rolls, trying to smooth and enlarge things but there is actually not very much that can be done. I think that, with a larger than stock tb, the only sensible thing to do is to fabricate some new tb adaptor and also skip the rest of the ducts.

Donīt know anything about the diameter of the air flow meter as I use a different system.


And, about your dyno power numbers; I donīt think that with your setup the 280 rwhp is that bad, should be equal to something like 330 – 340 hp on the crank, depending on type of transmission. Seems a little odd though that the max boost is only 0.4 bar with those numbers.


Best regards
Jan

 

Interesting topic. There are quite a few threads in some of the other model forums about bored/enlarged throttle bodies that a quick search turns up. Reactions are mixed, but one behavior they do seem to exhibit is "quicker" throttle response since at a given throttle position the butterfly is essentially open more.

Some found that quicker response attractive, others have not.

I have a TB for the XJR6 that was bored out by Maxbore, but I haven't tried fitting it yet. I had it fitted with the improved recall throttle spring when I had the R493 recall done last month, so it's ready to go. But that's a pretty low priority to tinker with at the moment.

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Hi guys

My dyno datas were 280 hp on the engine and 220hp on the rear wheels with 0.4bar Pressure from the Supercharger ! The higher the rpm the lower the pressure.

Today my jag mech called me , that a small part at the TB has been broken and at the bypassvalve also a part wasnt working. On Friday all parts will be installed in the engine. What do you think will bring me all tunings togheter ? Exhaust , Andys brackets , bigger lower Pully , Cold air intake , ported remanufactured Supercharger .