Hey guys

I ve been reading in these forums and i was wondering if someone could clear this up , i running a L28 with a fair warm cam, and i m have f54 needles in my SU , are these ok or should i get the SM needles that ztherapy have mentioned. If so would this change making any power difference.

cheers

Richard

It should, I also have a 280 in my 240 and runing SUs. I bought a set of SMs from Z Therapy but havent tried them yet. Going from a 240 to a 280 , the added CCs will require a little more fuel. The taper is much faster with the SMs , seems to be about the same at idle and at normal Rs but with your foot in it is should come on with the cam. At least this is why I am going to give them a try. I have a color tune so I will be able to see how the cylinders are burning up to 3000 Rpm .:classic:

Yeah I find that at 5000 i run out of gas and that s when my cam really starts to work .I have a stage 3 cam and I when hits 5000 the power just flattens out, but its my understanding that with this cam it sould be pulling really hard at thsi RPM. So am i right to assume that the SM needles will still give could fuel economy and more fuel at wide open throttle?

cheers

Richard

.... are all about. Fattening things up in the upper RPM ranges. The stock Z needles tended to lean things out up top and th SM's profile allows things to run a little fatter up high.

We have had a circumstance or 2 where guys were just flat not able to supply enough fuel through the fuel nozzle so we have supplied over size nozzles for them. Worked great.

On the other hand we are working with a customer who is complaining about his SUs running rich at, are you ready for this? 9,000ft!!! Duh, I wonder rich!! It's called no oxygen and all gas!! We see problems at Shasta at about 5,000'.

Thus ends the Friday morning consult.

for some reason my 240Z with a 280 engine has number 27 needles in the carbs.thats how it came when i brought it.

F.W.I.W. just got some wide band sensor readings the other day and was pleased with Ztherapy SU, SM needles and .101 nozzels. full radius airhorns, stock motor, 9.5 :1 compression, E31 head, E46 intakes, some cam & rockers, Pertronix ignition, MSD-6AL, Blaster coil, no smog, headers, Moroso muffler, fuel pressure is 2.9psi, was puttng out about a 13 to 14:1 AFR at a steady line. Don't mind being a little fat knowing we can back it off a little. But all in all I was glad to see the results were what Steve had sold us.

As far as driveability & idle no problem, I was only concerned about w.o.t. anyways.

:classic:

Hey Bruce, since you work at Ztherapy, can I get some advice. I'm planning to use a 280 bottom end with a E-31 head, should be between 10 and 10.5 to 1 compression, a hotter cam, hopful bigger valves. What needle and nozzle combo in SU's would you say to use? I know triple webers or the like would be best, but want to avoid the $$$ and hassle of them. Also would you say 10.5 to 1 is to much for pump premium (93 octane) gas? Thanx for your input!:classic:

Sorry, didnt mean just him, anyone else who has done this type of combo's oppinion is welcome too!:classic: :stupid: :classic:

... the deal just fine assuming your carbs are in decent shape and all the tuneup issues with the engine have been addressed.

SM needles for starters and over size nozzles as a second step if you feel you might have a fuel starvation problem. By the time these carbs might let you down on the big motor, the ticket will bust your pick anyway. You want to run out of carb before you run out of money......

You might read over the description of the ZTV-01 Tune up video for those engine related matters can can directly effect carb performance. We talk to a lot of guys who blame their carbs for things that are wrong in the engine. Not saying that's what you have going on here. Just thought I'd slip that editorial comment in as it really does get overlooked a lot.

OK, thanx for the info! Just wanted to make sure I was'nt setting myself up for any problems I would have to throw a lot of $$$ at to fix.

Just a quick question what does 13 to 14:1 AFR at a steady line mean im a little confused . Im running a L28 with a 42 79 cam with a N42 head? what sort of horsepower should this combo produce ?????

cheers

Richard

AFR would be a measure of Air and Fuel for my guess.

AFR if i had to guess stands for Air Fuel Ratio.

I have been intending to get a set of SM needles and the video etc.. for my car. However what I'm really interested in is a rebuild kit that includes all the ZTherapy goodies like the shafts that use a ball bearing to reduce wear around the shaft.

However I get confused easy with the whole deal, I would send mine over but the cost to send my cores and buy a set there is just out of my budget and besides I'd get more satisfaction from rebuilding them myself.

Let me know what you wanna do Richard as I would like to get some myself (SM needles) Perhaps the bigger nozzles as well.

We could order them together and perhaps save on shipping or whatever.

I also know a guy here in Melbourne who knows what he is doing with SU's and is running them on his Stroked L28. I can get you in contact with him.

Now that I'm on holidays I have some work planned for the car..

PS: I run out of puff around 5500rpm but i'm unsure as to what the problem is just yet.

I also hear that remapping the distributor is a must with a larger camshaft profile.

Gav