Hot-Air Guru's.....your help please!


Staff member
I have been doing some thinking with my car..and in my "pondering" I have wondered about a few things to get some air flowing...

Is there ANY WAY...AT open up the Turbo to Intake Adapter? I have a feeling if you can open it just a bit it will help spool, and might add a few Ponys!


I took a look at the Throttle body on my car the other day, and it looked small compared to the opening on my TA-33 Turbo....Can this be opened up a bit for better flow?

Thanks for you help....lookin for some tips!
Jay Jackson does hot-air t/b's too

on mine i smoothed out alot of the edges in the t/b like after the throttle plate were it gets smaller i rolled it in instead of it being a step up but first look in it from the turbo side and you will see it gets smaller at a point just before it goes bigger ...i opened that section to match the rest then rolled a nice smooth transition in it

for the stock turbo i had on my car it got smaller going in the housing to the compressor wheel but again in step ups .
so first off i bolted the t/b to the housing with the throttle plate out and went in it with a scribe and marked the housing.

then i cut the housing out to match the t/b and took the size in gradually to the compressor wheel so again no steep steps in the airflow.

as far as the adapter there really isnt much room to do any cutting in it just polish it up real good....also if you put it in the turbo outlet and rotate it around to get the best alignment and mark the adapter and housing so you can line then up when putting it together.
IMO, a ported TB should go along with a bigger turbo. People remove MAF screens and run open K&Ns to free up the intake side but imagine the effect a super small TB has before the turbo. Like I've said before, after moving the TB to after the turbo it spooled more than twice as fast and the car was all around more responsive.
I've been toying with the idea of trying to open the adapter up a bit. The small end actually has a fairly thick edge, it could probably be opened up nearly an 1/8 of an inch (or at least the edge could be radiused quite a bit to smooth the airflow).
Thanks alot for the help.....

I am happy with the stock size of the Throttle body where the MAF pipe bolts up...but it just necks down so much!

Is it ok if I just port it out after the TB butterfly?.....Kinda like making the part the the TB that is after the Butterfly the same DIA. as the front part (where the MAF pipe bolts to)

Kevin....if you have any new discoveres with the adapter..please let me know....Im sure that would add a few MPH if we could get it opened up enough.
Throttle body

If you have an after market turbo with a bigger compressor inlet opening than your opening at the back of the throttle body, IMO you can/t get all the benefits of the turbo. With the step behind the butterfly, the T B can be opened up to somewhere around 2 3/8 in. This can be done on a mill pretty easily. I just had a friend open mine up to 66 mm. (2 5/8 in. ) He went through the sides so we had to build the out side up with weld.
I have seen people talking about the PTE - 54. Does anyone know how this would compare to a 66 turbo?
I plan on using a John Craig 87 turbo built to a 66 with 009 inj.
with an intank and an external pump. Hope this will be enough FUEL.
I had my 84/5 TB matched to the TA-54 when I was going hot-air. if the 66 is in a TA housing it is probably the same size inlet as the 54. Any bigger and an inlet bell wouldnt fit. as it is, you need to feed the nuts on while you put the bell on or else they don't fit. When dave had it ported he had to weld a little material on where it was too thin on one side (broke through).

I will try to find my TB and measure it. then when I find it it's for sale :)