So couldn't wait any longer on the custom TB so had mine bored out the the max of 80mm ,new butterfly and all!
excited to try this thing out !

 

Who did that for you and how are you going to do a before and after comparison?

EDIT: how is this one different from the custom one you are waiting on?

Also what is the diameter of the manifold inlet? If you don’t match throttle body bore to inlet diameter you’re not really going to accomplish anything.

 

I should have clarified, there's another thread about manufacturing new larger throttle body but it doesn't look like it's going anywhere. I realize about the manifold inlet That's something I will have to tackle when I do the install, Do you know how hard it is to remove?
I don't want to disclose the source yet as I still don't even know if it will function properly, I found out it's not that easy to Port these things properly with a matched enlarged butterfly to sit at a proper angle and on top of that disassembly is a headache .
I'd love to do before and after comparison, But I'm not sure I want to spend the money and time, I'm sure in my case it will make a difference as I'm pushing a good to amount of power and stock 75mm seems way under sized, will see.

 

Depends on how involved you want or can get into it but this is the time to pull the supercharger, replace hoses, port the supercharger, inlet and outlet, manifolds, etc to truly get any further airflow and power increase potential.

EDIT: yes I agree 75mm is too small, should be 90-100mm. Audi guys do it all the time though they have TVS blowers that automatically benefit from increased airflow.

I am no expert on the roots style blower but as I understand it I think we have run out of much further gains without going to a larger volume or different type of supercharger.

 

Maxbore offer this service also

 

Actually, Maxbore no longer works on Jaguar throttles.

 

They are still listed on his website, are you certain? Also looks like he increase diameter by only about 3mm, doesn’t seem worth the effort.

 

For anyone who wants to give it a go, this one seems INSANELY cheap:
https://www.ebay.com/itm/2013-Jaguar...oAAOSwzcpdm76O

 

Thats not even the right car..

 

4,656.6 is the square mm of a 77mm bore, and 5,026.5 is the square mm for an 80mm bore. 350mm\2 more area which is about 8%, so not horrible. I think the OEM size is 75mm though, which is 4,417.8 mm\2 so a difference of 580, so about 12% increase.

 

I didn't say for your car specifically, I did say that it was a heck of a cheap price for anyone who would want to send something out to be opened up. I'm tempted myself.

 

Ahh got ya! Although on the 5.0 it might be sized properly already so not much gains.. do you know what the size is on a 5.0?

 

I've tried to find out on The Google, but haven't found anything quickly.

 

Not sure how restrictive the x150 4.2s intake set up is... if your bottle neck is at the TB, then you will see gains. Regardless, I am sure you will notice more response and possible power coming in earlier on your curve. Curious to see myself. Hoping for the best.

5.0 TB is 82mm btw



.

My custom 83mm TB from that other thread is in New York going through customs right now. I am also getting the plenum ported to match the TB, as well as getting the supercharger outlet opened up a bit and polished. I have a Pro M racing 92mm MAF and housing I will install all the same time. Supercharger inlet and internal is already ported, and I have the Range Rover 90mm inlet tube. So hopefully we see some gains on the old x350.

Only downside to this whole custom TB thing is i have to transfer the electronics from my current 75mm Tb to the new larger one. Looks tedious. I usually like to wrench, but I am not looking forward to this.

 

Yes, I reached out to him a few months ago. Maybe that's changed since then.

 

Thanks for the info and pics. I'm looking at the na version vs x150/str on your photo, does it appear like the NA version has thicker walls so possibly more room for boring it out farther? And I'm assuming bolt pattern is the same.
Good luck with you project btw !

 

Update: so after finally installing the tb , porting the intake elbow. I wasn't too impressed by lack of improvement in performance of the car, and actually it felt like I might have lost some. Well after searching and checking everything over multiple times I found out why.
Very important to anyone upgrading and porting throttle bodies : Angle of opening becomes slightly off, not open at 90degrees at full throttle, so you will actually loose performance and airflow. We do not have a hard stop but it's all controlled electronically and having a larger butterfly throws things off and not optimal.
Solution I figured out in about a day of digging in the complex Denso ECU code, trial after trial and after around 20 ecu reflashes I finally got it . Now butterfly perfectly opens to 90 at full open throttle and power is back and plus some!!
Live and learn!!! Hope this helps those in the quest for more power.

 

Will you be able to measure any improvement?

 

Not planning to dyno this mod but expecting it will benefit the system overall maybe 10+hp , . Will see with track times