So I got a sick deal on a 70mm tb off a buddy of mine awhile back, and I later noticed that the 70mm bore is too big for my manifold (jrsc s-tube) since the actual 70mm bore overlaps into the iac passage. What is the typical workaround for this? I searched quite a bit and haven't found any info or products addressing this issue, all I've found is tb adapters for going from Ks to other Ks like wire to cable conversions, etc. Are there adapters that I just haven't come across or do I need to fab up a custom s- tube?

 

you can send the stube to lht to get the max bore, i think i had them get real close to 70mm on my LHT manifold setup, or you can buy a p2r tb spacer but it wont do you no good if nothings portmatched close.

 

my victorX is bored to a 76mm. we welded the inside of the iacv port so the "meat" to seal was on the inside.

 

I have a feeling I'm going to end up doing just that. I thought of offsetting the tb to the right a hair but the sealing surface between the bore and iac passage is still razor thin once the tb flange is bored out far enough. Did you weld yours all the way shut and then have to redrill it like doing an auto-manual conversion or just weld some meat along the lip?

 

I'm running a Blox 70TB with no issues and JRSC. Maybe you should just try starting the car and see how it goes even though you question that passage issue?

LHT can port the S tube, which I have not had done.

 

just welded and planed it flat.