Carb replacement

[LeonV]

Without forced induction of some sort, SUs, Webers, Hollys, etc are only going to supply as much air and fuel as the engine is going to draw..... The infernal combustion engine is afterall nothing more than an air pump.

Are you trying to imply that SUs are able to optimally feed each cylinder? The manifold design for SUs has been proven to be flawed in terms of mixture distribution to each cylinder with WB02 data-logging. The AFR between cylinders is not consistent, and there are some nice bends in there as well adding more pumping losses.

On the other hand, a triple setup gives each cylinder its own venturi. Bends in the intake tract are minimized and the mixture cylinder-to-cylinder is more or less consistent. It is also possible to do effective intake resonance tuning with this setup by simply switching out bell-mouths.

Yes, SUs work well and are great for someone looking for street driving and decent performance. However, when it comes down to tuning and maximization of power (or efficiency), the Webers have a profound advantage.

Yetterben brought up a good point in that the EP racers need to keep the stock carbs. You think that if carb choice were unlimited that SUs would be preferred over Webers? I think not.

As for the OP, if you don't know a lot about cars don't even think about triples, unless your wallet feels too heavy.

[yetterben]

This has been documented. I did not wanna bring this up either as this war never ends the little skirmish battles get won but no one can ever agree.

I stand buy my 34mm x6 theory. I also stand buy unlimited tune ability.

In this case though the OP sounds like he needs hassle free driving.

As far as pricing though. I want to make clear unless you are buying triples new (webers anyway) they are not worth 1500. USed webers are worth about 100-125 a pop unless there is documentation to back up a rebuild. Or how long they have sat. Why webers have dropped in price...loads. One can get a new carb for 275 bucks now. I learned instead if buying floats and needle jets to just buy the whole top cover for 70 bucks. Gets you 90 percent of a rebuild brand new float brand new shiny cover bolts etc.

Intakes are a different bag. I think the cannon/pierce mani is kinda junky. The two i have had where very rough, casting flash was really bad. the mikuni mani i had was top notch. The kamereri intake is very very very nice. for 450 bucks you get a super sweet intake throttle linkage the works.

Oer is still being made and qulaity has stepped upped. They are setup to handle boost as well up to 15psi. I almost went this route when i had my hks blowthrough setup,But at 550 a pop thats alot of cash-olo

I think what ultimately needs to happen is a dyno shoot out with the same car and different induction setups. From a non biased person at a location yet to be chosen .

I just wanted to put it out there that these carbs are not worth 1,500 and surely run from msa setup. The people i have talked to lately say they have been getting mix matched carbs and jet setups.

Mikuni and all the other carbs mileage is gonna vary. Some cost more than others. Webers are the ultimate in tune-ability. But there is something to be said over the mikunis or even the oer/sk rip offs of mikuni for a time piece.

Edited July 1, 2010 by yetterben

[LeonV]

I agree about the pricing as well, $1500 is ridiculous! Might as well go standalone FI at that point. I think that $500 to $800 is more like it for a complete triple setup, depending on condition of course.

I was actually planning to go dyno testing with well sorted SUs vs. Weber 40mm triples when my Z is back on the road. I have both setups and am curious as to the quantitative difference between them.

[Zs-ondabrain]

Well, There's a 1/4 mile shoot-out coming up on the 18th and I'd love to have the triples (Weber 40DCOE's) rebuilt and tuned by then. Then.... Make a few runs on the SU's, then take 40 minutes and swap in the Webers, linkage and timing and make 3 runs on those.

Post the results and let the conversation fly. This way, it'll be the same car, same motor, and same driver. I love my new SU's but also love a well tuned set of triples. I can say it will be a non biased test as I'll be happy to just be able to run the quarters, no matter what's under the hood or feeding the motor.

We'll see.

Dave