Guest Looking for apt in Alb Ny Posted July 25, 2003 Share Posted July 25, 2003 HI. Its Juan . I was wondering if anyone could use anything larger than 60mm from a stock 240sx. 65-70mm? Would making adapters from Mustang be worth it. I can most likely make it. Thanks Quote Link to comment Share on other sites More sharing options...
johnc Posted July 25, 2003 Share Posted July 25, 2003 I'm sure you could sell a bunch. Bigger throttle bodies are an aftermarket upgrade "must" despite their lack of benefit to most street L6 engines. The wonder of marketing. Quote Link to comment Share on other sites More sharing options...
Guest Looking for apt in Alb Ny Posted July 26, 2003 Share Posted July 26, 2003 Hi John do you mean it wouldnt be benificial or lack of availability to the Z Thanks Juan Quote Link to comment Share on other sites More sharing options...
johnc Posted July 27, 2003 Share Posted July 27, 2003 From what I've been told and what I've seen on engine dynos, the L6 engine needs the most work on the exhaust side. That's where the "restriction" is - in particular the two center exhaust ports. Just bolting on a set of headers does little to resolve this because the stock exhaust manifolds are well designed. Unless a person has made an effort to increase velocity on the exhaust side through head work, a bigger throttle body just slows the intake charge down and can reduce overall VE because of the time it takes to accelerate the intake charge into the combustion chamber. It might only start to work at higher rpms where the momentum of the intake charge can overcome the reversion from the exhaust side. Remember, the stock SU carbs work very well up to about 225 horsepower and a big reason for their effectiveness is the variable venturi design. Replace that with a "big hole" and you're reducing intake charge velocity. Also look at the horsepower being made from normally aspirated race engines that have to run restrictors. The Nissan V6 run in the ALMS LMP675 class breathes through one 30mm restrictor (2002 rules) and makes over 400 normally aspirated horsepower. But, again, reality has little to do with what sells in the automotive aftermarket. You'll be able to sell a bunch of these bigger throttle bodies 'cuz the "marketing education" has already been done for you. FYI... my 305hp NA 3L runs a 65mm TWM throttle body and it has extensive head work, a big cam, custom intake, and the 1.75" Nissan Comp headers. FYI2... None of the above applies to a turbocharged engine 'cuz they be different animals. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.