I'm finishing up my ls/vtec bottom end atm, and I've been turning my attention to my homemade ITB project and wanted a little input as to runner length. I'm not shooting for a high-hp goal, it's just a low-budget build consisting of a stock block LS, stock pistons, and stock rods with ARP bolts and coupled to a mildly ported b16a head with a set of SiRII stock cams. The throttle bodies I have came off a 1300cc gsxr and thanks to Crome's new ITB utilities on the p30 rom base I'm going to use the stock gsxr tps sensor re-calibrated to the honda maps. Basically I'm getting ready to weld on the runners for the ITB's, and I'm trying to find what a good length would be to keep optimal bottom end torque but still maintain a good higher rpm curve. Anyone with some hands-on experience I'd appreciate the input, and thanks in advance!

 

1st off - bump for a fellow DIY ITB builder.

2nd - i believe there's some math on calculating runner length for ITB's on this page, if i remember correctly. https://honda-tech.com/zero...age=2 if not, there's a bunch of otherwise useful information for ITB setups.

hope this helps dude.

 

Thanks man, that link helps alot. After reading through that article and seeing how it affects low-end torque, I'm starting to wonder if ITB's are really the route I want to go.