If not mistaken, original is 2" from the extractor to the muffler. But don't bother to alter it into bigger size as it will decrease your power, if you like to have a louder or more aggressive sound, change out the whole system. You can try PM "Semperfi" as he have the whole new complete set of HKS muffler original from Japan for GTT. This might help you to get better HP and more aggressive sound.
Holla... Been a while since I posted DIY stuff here. Been kinda busy with 101 things since the New Year. Those who have seen it in ZTH Mag, here is the Forum page to discuss... Those have not, grab one! This round's...
hey guys & master's of rotary engines...
Just wanna know like if its all right or i should not try it at all....
I'm planning on putting a 13b into a datsun 510 SSS (year of make 1971)