throttle body boring service and repair


Maxbore is a federally registered trademark, in business since 2002.
If you find another business/website using our trademark, please contact us, there might be a free TB boring service for you.

Updated May 2019.

Open regular hours, (8AM to 5PM East Coast)

Welcome to Maxbore ® throttle body boring service.

Please click on PICTURES at the top right of the page to see the latest work done at Maxbore ®

High Quality, High Quality, High quality. Those are the three main standards by which Maxbore ® operates. Maxbore ® is a highly specialized machine shop dedicated to boring and repairing throttle bodies. You are dealing directly with the machine shop, no middle men involved.


(321) 277 6151 .Open from 8 AM to 5 PM Eastern. NO TEXTs please

Or email me at:

Throttle Bodies sent in that are not found on the website and/or cannot be bored, are subject to a $15 return shipping fee. Please contact me first if you don't see your TB or if you are not sure if I can bore it. Please look in the "pictures" link at the top right of the page to find your particular TB.

EUROPEAN THROTTLE BODIES $150, please click here for more info

Maxbore prices depend on the number of butterflies your order has.

Simply count the number of butterflies and multiply by $125 and that's it.

The return shipping cost is included in the USA.

Canadian customers $25 Shipping.

All other International countries pay actual shipping.

Click here for shipping address

Service Purchase

Boring service for each butterfly your order has.
Click add to cart, then select quantity

European TB boring service
Click add to cart, then select quantity

TB Shaft machining. $35
Shaft is machined to a thinner profile to reduce turbulence. New low profile (flush with shaft) screws are installed. Not available by itself at this price, only as part of TB boring service.

TB Gasket $10
New, reusable OEM type gasket made to fit bored TB

Adapters and Spacers $35
This service machines any adapter or spacer SENT IN BY YOU, to the same size as the bored TB. Spacer is not included.

Canada and international shipping
No GROUND shipments from Canada. There is a $45 fee for Ground shipments from Canada.

Canada shipping $25

International shipping
Actual shipping cost.
Contact me for shipping quota.

Canada Shipping

Click here for shipping address


Maxbore ® is an internet only Business. Any other shop claiming to be Maxbore ® is not being honest.

This website is the ONLY way to get your TB bored or repaired at Maxbore ®.

Maxbore ® is a one man operation. My name is George, I own and operate everything involved with TBs. I do everything from disassembly, cleaning, boring, machining butterflies and shafts, assembly, ordering material, packaging, shipping, replying to emails, as well as working on my cars.
I am humble, I am thankful to all performance enthusiasts, to my family, and to all the customers over all these years that have allowed me to do this.

The MAXBORE ® process.

I have been asked many times if I make a new butterfly, if I bore or just port the TB and so on. I hope to answer most of those questions with these pictures and descriptions:

The work begins by inspecting your TB. I make sure it operates correctly and that there are no cracks or obvious damage.

The TB is fully disassembled and the factory butterfly is discarded.

The bare casting is then put on a lathe and bored to the max size possible. I bore the TB evenly from front to back. If possible I taper the opening ( filter side) to create a venturi effect which helps move air through the TB faster. After it is bored and polished, the casting is thoroughly cleaned, degreased and pressure washed to remove machining chips and aluminum dust from the polishing.

Then it's time to make a new bigger butterfly. I make all the butterflies from scratch, in house. They all start as a raw sections of brass or aluminum alloy (6061 T6) if your TB came with an aluminum butterfly.

The butterfly is now a blank ready to be machined to size. The butterflies I make are machined to .0005 tolerance, that is 1/2 of a thousand of an inch. The butterfly is custom sized for each TB, it has to be that way in order to get the most out of each TB.

The butterfly is not round, it's actually oval in shape since it has to stop at an angle inside the perfectly cylindrical bore. I can custom machine butterflies at any angle, thickness and diameter.

Once the blank is turned into a machined butterfly, I test fit it into the shaft. The slot in the shaft needs to be enlarged to accept the new bigger butterfly.

The butterfly now fits inside the enlarged slot of the shaft.

The casting, shaft, and butterfly are fitted to ensure all parts move without issues. The butterfly is marked for the location of the screws and drilled for clearance.

Once I am sure everything works as it should, I put the TB back together and test it again for proper operation. A lot of care is taken to make sure you get a TB that works like it's supposed to. I do not remove or seal important vacuum ports or coolant passages. For racing purposes where some of those features are not necessary, I can plug or remove those parts. There is an extra fee for those services, please contact me to discuss any custom work you'd like to be performed.


Turn around time is 5 days from the time your TB arrives at the shop for TB orders and 7 days for TB/Manifold orders. This is a good faith estimate and depending on circumstances sometimes beyond my control, it could take a few days longer. I do custom machining on used parts that sometimes do not cooperate. Turn around time does not include shipping time from you to maxbore ® and viceversa. Thank you for understanding.


Your throttle body comes back with a limited lifetime warranty on workmanship. Warranty does not cover Sensors. In order to obtain warranty work, the throttle body must be returned in the same condition it was sent to you.
This warranty will be void if you disassemble, or modify your throttle body in any way. There will be a flat $50 fee for any repairs on throttle bodies that have been disassembled or modified.


You agree to provide Maxbore with a minimum of one opportunity to correct any issues that may arise with your TB. There are no automatic refunds without first inspecting the TB. You are responsible for shipping costs to Maxbore and Maxbore will pay to return your TB. Brand new AND Junk Yard TBs sent to Maxbore without testing first for operation or compatibility, are not covered under the refund policy. It is STRONGLY recommended, installing the TB in your vehicle FIRST to make sure it actually works in your vehicle before sending it to Maxbore.

Do not wait until you get it back from Maxbore to find out it doesn't work with your vehicle.

If you send a TB for boring without first seeing it work in your vehicle, you assume all responsibility. Maxbore will work with you at our discretion on a case by case basis.

Please email me if you have questions not answered here.

Parts ( Throttle Bodies, Spacers, etc) left at Maxbore
from date of notice of completion of work, become property of Maxbore. Parts will be put up for sale to recover labor costs. You agree with this policy by sending your parts for machining at Maxbore ®.

Thank you!