I just got my 73 240z running for the first time and was underwhelmed with the power. I was not expecting a rocket ship, but I am now wondering what simple things I can do to add to the horse power. It already has a dual webber carb. What mods have people done to the exhaust and what have the results been?

Zover

There are a few bolt on modifications that you could do to add a few more ponies. Unfortunately none of them will be felt in the "seat of the pants". Headers-exhaust maybe 10+ hp, Cam maybe another 10+ hp. Upgrade the ignition, and a proper tune. Your looking at maybe 150 hp. Do a compression test to determine the current condition of your engine. Maybe you need a rebuild? One of the biggest upgrades you will notice is people swapping out the L24 for a L28 (280 ZX motor). It really all depends on how fat your wallet is and how fast you want to go. You could go Turbo or even the dreaded V8 swap. But with all swaps you must realize that you must also be able to stop the car. A suspension rebuild and a brake upgrade is the first step.

Let us know what your dream is and we'll help you if we can.

I have no desire to swap out engines at this time. Is there a specific manufacturer for header exhaust combo that people recommend?

Zover

i kinda like motorsport auto's set-up...

I would make absolutely sure that the engine is performing as expected. Have you driven other 240Z's or know anyone who has one? If the car is not tuned properly the performance will be awful and adding headers, etc. won't do much good.

I don't do webbers , but I know that they need to be jetted correctly . This is a start. I agree with the others posted before me.

Duel webbers, well that's the problem.

Back to Su's or if you want webbers then triple's....

MOM

When you say 'dual webers' (one are you referring to DGV's? If so, that is probably the source of your discomforture. If you have the downdrafts, I've yet to see a pair of those outperform triple sidedrafts or even a properly set up pair of SU's.

I feel stupid to ask, but what is everyone mean when they say SU's.

Zover

SU's are the standard side draft, single venturi carbs used on the 240 and 260 here in the US. Actually they are 'SU style' carbureators manufactured by Hitachi for use on Datsuns. If I reacall correctly SU stands for 'Skinners Union.' I think that is the company in England that originally made them for use on Jaguars, MGs, Triumpths, etc. We refer to the Datsun carbs as SUs but they are actually Hitachis.

one thing you can do to really liven up the performance is to change the diff. gearing , got to a 390 ratio this will make a big difference. If off the line performance is what you are after.