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Boring out the Throttle Body

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Old 08-20-2012, 07:33 AM
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Default Boring out the Throttle Body
Have just received a message from www.maxbore.com that he now works exclusively on throttle bodies, and does have time again to bore out the Jaguar ones.

I had done 1 AJ26 TB, which went from 75mm stock to about 80.50mm, and can recommend him for the work, and hope that he will also be very responsive now as he has focused solely on TBs.
 
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Old 08-20-2012, 01:10 PM
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Any drive-ability issues? Is any tuning required on these cars to take advantage of the larger TB bore?
 
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Old 08-21-2012, 12:25 AM
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There is no tuning required, though of course some porting on the intake elbow is required, but that’s a simple one. No drivability issues as well, I have gone even much further on my setup.
 
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Old 08-22-2012, 08:36 AM
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When dealing with ported TB's in the past, I've often found the throttle to be more "twitchy" as the transition from idle to drive was more sudden. No issues with these ones?
 
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Old 08-23-2012, 01:23 AM
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Our engines aren´t light fast revving ones, so that might be the reason why I haven´t noticed any of this twitchiness. Going from 75 to 80 is a small step from the idle point, although it does help of course high flow as it increases the airflow capacity about 13%.
 
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Old 09-04-2012, 10:13 PM
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Default What about the pontentiometer?
Did you have to reset the pontentiometer/tps?
 
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Old 09-05-2012, 12:32 AM
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The ECU is checking the positions (for idle) at ignition on, so small deviations will be adjusted for.
 
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Old 09-06-2012, 08:28 PM
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Originally Posted by avos
Have just received a message from www.maxbore.com that he now works exclusively on throttle bodies, and does have time again to bore out the Jaguar ones.

I had done 1 AJ26 TB, which went from 75mm stock to about 80.50mm, and can recommend him for the work, and hope that he will also be very responsive now as he has focused solely on TBs.
I don't mean to hijack the thread, but what is the 90mm throttle body do you use on your kit? Will it work with the m112?
 
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Old 09-07-2012, 12:20 AM
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Besides allowing more air thru, the more vacuum you have in the intake, the more power is needed to turn the supercharger, resulting in less power to the wheels.

So I have no doubt it will have an good effect also on the M112 if you work on the full intake, But the costs for a 90mm TB and electronics doesn't make it worthwhile imho, your far better of then going the TS road in the 1st place.

The bore out is the cheapest method and should give some result in conjunction with a modified intake of course.
 
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Old 09-07-2012, 11:17 AM
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I just sent my TB to Maxbore and it was only a one day turnaround, so I can recommend him fully. 75-> 82.5mm
 
Last edited by WaterDragon; 06-09-2013 at 03:32 PM. Reason: new info, deleted incorrect info- there are "other" sources for TS kits now locally in San Diego
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Old 09-07-2012, 03:33 PM
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Wasn't really asking for free, was wanting to know the price and if it could be sold as a bolt on so I could decide if it was worth a try.

No twin screw for me, so looks like boring is the only option.
 
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Old 09-07-2012, 06:26 PM
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Originally Posted by WaterDragon
AVOS has spent literally a thousand hours doing the R&D to make the best Jag TS adapter kit out there, so I can respect that he does not want to give away for free the hard won gains of his sweat and tears by revealing for free all his breakthroughs. The larger TB, as I understand it, was a source of endless problems, but has now been fixed.

I just sent my TB to Maxbore and it was only a one day turnaround, so I can recommend him fully.
I have the Twin Screw with the 90mm throttle & the only problem we had was a few issues with the interface on a US spec car. That was over 2 years ago & only a small bump along the road. I would recomend to anyone who wants to modify their car to save their money & just do the Twin Screw. I tried them all along the way. It was all a waste of money.
 
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Old 09-23-2012, 06:28 PM
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Originally Posted by JgaXkr
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I have the Twin Screw with the 90mm throttle & the only problem we had was a few issues with the interface on a US spec car. That was over 2 years ago & only a small bump along the road. I would recomend to anyone who wants to modify their car to save their money & just do the Twin Screw. I tried them all along the way. It was all a waste of money.

I see you are the only one in the USA that has the twin screw.

What numbers has your car pulled down on a dyno?
 
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Old 09-23-2012, 08:20 PM
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I hope to do a dyno run when I finnish with my latest upgrades. This should be somewhere around Thanksgiving.
 
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Old 09-23-2012, 11:37 PM
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I'm guessing somewhere in the low sixes.
This car must be the most powerful XKR of this model in the USA to date.
 
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Old 10-02-2012, 09:57 AM
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Anyone know the stock size on a STR?
 
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Old 10-03-2012, 01:04 AM
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Its also about 75mm, and from the looks of it you can also go to about 80mm (or slightly more).
 
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Old 10-03-2012, 07:20 AM
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Is it advantageous at all?
 
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Old 10-03-2012, 07:43 AM
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The TB is designed for a certain amount of airflow, if you increase the latter it will be advantagous obvioulsy. This is one of the reasons I am using now a 90mm one.
 
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Old 10-07-2012, 05:02 PM
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hi,
- My 1999 XJR throttle body was sent to Maxbore.com, he does a nice job, it is now 81mm, I am having trouble locating assembly and set up instructions, Andre (avos) sent a sketch so far, but would anyony know where to find detailed info on settings, from a Nippondenso manual or similar please
 
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