throttle bodies and jms inlet runner length comaprison

[GTaylor]

Hi everyone, as far as im aware inlet runner length has an impact on torque, was wondering if people would post up what length inlet they use (ie from cylinder head face to trumpet face) and what dyno figure for torque they had. obviously the vehicle spec will have an effect on this, but trying to see whether increasing trumpet length would be beneficial on the jms setup. Any help or info would be much appretiated. Greg

 

[Andrew Cooke]

Hi everyone, as far as im aware inlet runner length has an impact on torque, was wondering if people would post up what length inlet they use (ie from cylinder head face to trumpet face) and what dyno figure for torque they had. obviously the vehicle spec will have an effect on this, but trying to see whether increasing trumpet length would be beneficial on the jms setup. Any help or info would be much appretiated. Greg

That info won't really help you as the JMS kit is a Helmholtz plenum and a single trumpet is just that. It's apples and oranges...

 

[TimR26]

Tom experimented with a longer runner length on Nick's 172 Cup. I think he didn't market it because the gains weren't enough versus the cost of removing the slam panel, aerocatches etc

 

[Nick172Cup]

Tom experimented with a longer runner length on Nick's 172 Cup. I think he didn't market it because the gains weren't enough versus the cost of removing the slam panel, aerocatches etc

This is true to an extent, with the extended runner length it only made a few more bhp but made almost 10 lb/ft of torque which is a reasonable gain. Guess it depends on how compromised your car is already.

 

[GTaylor]

Thanks for the info, 10 lb/ft is quite impressive, il build an inlet and see what it does. cheers to all Greg