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kcoke

Triple Carbs vs. SU

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What would be better for my L24? I Have a racing performance Cam with MSA 3 into 2 headers and electronic ignition. What would be better for my engine SU carbs or a set of triple carbs? Or even a 4 barrel conversion or the dual webers? I want to make my engine fast. Its a 1971 Datsun 240z. My goal is to smoke the stock GT's around.

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Anyone else get deja vu reading this???

yeah. haha.. go search man just type it up.

haha like just do it from nike AHHAHA ROFL

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kcoke,

You will find more info than you'll know what do with by using the search function, both here and on other sites. If your Z has the four-speed, you probably have the 3.36 geared R180 differential. Installing a 3.90 or 4.11 differential will dramatically affect your acceleration, probably much more than carburetor choice. A five-speed will still provide good economy.

Having said that, There are many 240Z drivers running mid 13's to high 12's with well-tuned SU's. Most use the 2.8 liter block bored and stroked, but there are several running just the 2.8 liter block. Almost all have done some serious head work in addition to cam, ignition, headers, and proper gearing.

I've seen, and read about, some very hot Z's running just the 2.4 block. And if you really love triples as I do, then go for it. They will usually improve your low-end torque and add horsepower over SU's. With your 2.4 block, I would stick with 40's, rather than 44 or 45's. But be prepared for jet swapping and dyno tuning to get them properly set up and to get the most out of your triples. This will not be cheap. Once you hear the sound of triples and experience the performance, you'll be hooked as I am.

As for dual Weber DGV's, they were originally used on the 73 240's and 74 260's to replace the poor performance-designed flat top low emission carburetors. But once used round top SU's became available, many ditched the DGV's in favor of the earlier round top SU's. The DGV's are more complicated than the SU's, but they can be made to run well.

All of the above are my opinions, and their are many, many more knowledgeable folks on this site. Some of them will chime in to correct or add to what I've said. But do yourself a favor and do the search, too. Good luck and best wishes in reaching your performance goals.

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but how about a set or triple SUs? We are doing the development (say casting of manifolds) work to duplicate the triple set-up Steve Epperly had on the ZTherapy Z. We can guaranty the pleasure of driving on SUs, with the punch of three of 'em, with the simplicity of playing with mixture nuts & three screws to get 'em right, while being so subtle the average car guy wont know the difference.

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but how about a set or triple SUs? We are doing the development (say casting of manifolds) work to duplicate the triple set-up Steve Epperly had on the ZTherapy Z. We can guaranty the pleasure of driving on SUs, with the punch of three of 'em, with the simplicity of playing with mixture nuts & three screws to get 'em right, while being so subtle the average car guy wont know the difference.

Sounds good I saw some videos on YouTube.com of Mike's yellow 240z with triple SU's manifold it looked awesome. Is that your work? :rambo:

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... that Steve built as the proto-type. Bolted them on did the tweaking and they have run like a swiss watch ever since ON BOTH CARS. They were put on Mike's car to get it up and running and for the show, but they will now be used for casting pattern work.

How many of you here think you would be interested in this lash-up complete ready to bolt on tweak 'em and go??

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... How many of you here think you would be interested in this lash-up complete ready to bolt on tweak 'em and go??

Hi Bruce, you can mark me down for a complete setup.

Would you need my SU's back? They were done by Scott B. a few years ago, and I have two that need overhauled as well.

Seriously interested,

Chris A.

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Chris,

Either call me at 503-587-9800 or email me at sales@ztherapy.com and we can go over your questions. I'd say that someone out there might benefit from those early ZTherapy carbs more than we would by dissasembling them for core parts. They are not quite up to the standards of our current production but should still have a lot of useable life left. Anyway Ebay or ??? might be the way to go when the time comes.

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but how about a set or triple SUs? We are doing the development (say casting of manifolds) work to duplicate the triple set-up Steve Epperly had on the ZTherapy Z. We can guaranty the pleasure of driving on SUs, with the punch of three of 'em, with the simplicity of playing with mixture nuts & three screws to get 'em right, while being so subtle the average car guy wont know the difference.

I could be persuaded...

Will

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IF I were to finish my yellow car, and if that finished product included an L28 rather than the L24 I have in it now, I think triple SUs would be extremely cool. I don't think that'll happen - but I can't rule it out...

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those early ZTherapy carbs...SNIP....are not quite up to the standards of our current production

OUCH!!!!! That stung a little considering what I spent on them.

Okay, Bruce, when the time is right for me I'll call you about getting triples.

Chris A.

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OUCH!!!!! That stung a little considering what I spent on them.

Okay, Bruce, when the time is right for me I'll call you about getting triples.

Chris A.

Chris, Just saying that the product out the door since Steve took over how the carbs are done has resulted in a better carb. Not that Scott necessarily built a bad carb the QC was up and down. If yours are working fine you musta got an UP set and that's good.

Steve, by the way, fixed all the Scott's "others" under warranty gratis for the duration of the warranty periods just so you all know where he is coming from customer care wise.

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... that Steve built as the proto-type. Bolted them on did the tweaking and they have run like a swiss watch ever since ON BOTH CARS. They were put on Mike's car to get it up and running and for the show, but they will now be used for casting pattern work.

How many of you here think you would be interested in this lash-up complete ready to bolt on tweak 'em and go??

They seem like a very cool set up, however I have bought myself a set of Triple 44 Mikuni's already. I have 4 SU carbs here also, so I could easily set this up with just a manifold. Given I'm in Australia and shipping all items and the extra expense of conversion from US to AU it probably wouldn't be worthwhile for me.

I'd consider buying a manifold just for the ultra cool triple SU look. It looks nice and standard but offers that bit extra.

Have you got anything to compare Triple SU's with Triple Mikuni's? Any pro's con's?

So at this stage I'm not interested, however I'd be interested in a Triple SU's manifold and possibly linkage set.

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my guess is you could sell quite a few of tripple SU manifolds if somebody made them up. It would be interesting to get some feedback on any performance gains!? they certainly would look pretty cool though, i would be up for one manifold!

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what about the issue of the sharing of the carbies? i know that webers/mikunis don't have that problem because there is one barrel per cylinder, but IIRC there was some controversy over the firing order and the separation of the SUs.... not trying to start an argument, it's just that i have always bypassed triple SUs because of that "issue"

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what about the issue of the sharing of the carbies? i know that webers/mikunis don't have that problem because there is one barrel per cylinder, but IIRC there was some controversy over the firing order and the separation of the SUs.... not trying to start an argument, it's just that i have always bypassed triple SUs because of that "issue"

Just because something isn't perfect doesn't mean it won't work. Yes there is a firing order issue. But Jags, Austin Healeys and I think Triumphs all ran triple SU's on a 6 cylinder from the factory.

I for one would be interested in seeing a back to back comparison of dual to triple SUs to Mikunis or Webers. Especially if you were using Cary's old engine. That would really be applicable to my own situation. I expect that the Mikunis would come out on top, but I would be happily surprised if they didn't.

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I for one would be interested in seeing a back to back comparison of dual to triple SUs to Mikunis or Webers. Especially if you were using Cary's old engine. That would really be applicable to my own situation. I expect that the Mikunis would come out on top, but I would be happily surprised if they didn't.
And even if the Mikunis did come out on top, it wouldn't surprise me at all if the difference was rather small.

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Chris, Just saying that the product out the door since Steve took over how the carbs are done has resulted in a better carb. Not that Scott necessarily built a bad carb the QC was up and down. If yours are working fine you musta got an UP set and that's good.

Steve, by the way, fixed all the Scott's "others" under warranty gratis for the duration of the warranty periods just so you all know where he is coming from customer care wise.

Thanks Bruce, I must have got an UP set then. So I'm not upset!

Just because something isn't perfect doesn't mean it won't work. Yes there is a firing order issue. But Jags, Austin Healeys and I think Triumphs all ran triple SU's on a 6 cylinder from the factory.

Yep, my brother-in-law's Healey runs like a scalded dog. Big 6 with triple's stock.

Chris A.

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