Zrunner

My drag racing journey began in the summer of 95 when I went to Farmington Dragway in N.C. with a friend who raced his Plymouth Barracuda at the track regularly.

I had always street raced my cars since getting my driver's liscence in 1983, but I had never actually been to a dragstrip.

I planned on just trying it out once, but after the first run down the track in front of hundreds of spectators I was hooked!!

There's nothing like speeding and smoking your tires without the fear of flashing blue lights in your rear view mirror!! LOL

I have tried out five different variations of 6 cylinder Z motors over the years and have learned MANY little tricks that can be used to improve your Z's timeslips without having to spend a dime!!

There is nothing like free power!! hehe

I have had many goals that I have reached for over my years of drag racing , but my most exciting moment was when I achieved my first 12 second timeslip with STOCK 240Z Dual SU carb's!!

I ran a 12.94 @ 104.49 mph on Sept 17,1999

Do not ever underestimate the power of stock Datsun parts with a few minor tweeks!!

My best timeslip to date is a 12.88 @ 105.8 mph which I set on Nov 17,2000 at Rockingham dragway.That run was done with my now modified big bore Dual SU carbs.

I had trouble hooking up off the line due to poor track conditions that night ,so I am hoping to get my first 12.79 timeslip sometime this year!

My car is a daily driven, stock weight 71 240Z with a slightly unorthodox 2.9L stroker motor. I run my Z without the aid of Turbos ,Superchargers or Nitrous. In race track terminology that is referred to as an ALL MOTOR car.

You can read more about my car on this site by clicking on the articles icon on the very bottom of your screen.

For those of you that have never tried drag racing your Z, I can only suggest that you find your nearest track and go on a Test and Tune night where you will be able to make unlimited time runs for about 4 hours a night.

You will meet some great people at the dragstrip and really enjoy yourself.

I currently race mainly at Wilkesboro Dragway in Wilkesboro N.C. on Thursday nights from the Spring thru the Fall, but I also run at Farmington Dragway near Winston Salem N.C.
Shadyside Dragway near Shelby N.C.
Mooresville Dragway in Mooresville N.C.
and the 1/4 mile at Rockingham Dragway in Rockingham N.C.

I hope to meet some of you at the racetrack this coming year!


Later,norm

Zrunner

Z

eurozx

Welcome NORM, thanks for joining the board. I love your car man, great progress on all the work and I loved reading the interview zdriver? did with you. If i ever come out to Cali [next year] we all should get together

www.eurozx.com

eurozx.org

240z

Hey Norm I read the article on your Zed when it was posted on this site a couple of months back. I'm curious as to whether you can give me advice on how to get the most out of my SU's I recently had the throttle shafts replaced and bushed as both were worn and performace shot up. I understand you know many tricks to getting the most out of these carbs and I'm very interested in how to tune these carbs as I've had a hell of a time trying to learn. I understand I need a vacumm guage and colortune kit is this right? If so what should I get and what will I need to get the best performance out of my L28 Zed fitted with Dual SU's
Thanks Alot,

-=240z=-

Zrunner

Hey 240Z, get some performance SM fuel needles and the large dual K & N airfliters.
Smooth the sharp edge on the bridge in the carb body and the edge of the airflow piston with some 400 grit emory paper.
You can also file down the throttle shaft in between the screws to increase airflow capability.
Get a carb airlfow synchronizer tool and balance the airflow after turning each fuel mixture nut down 2 1/2 turns.You may need to turn your fuel mixture nuts up or down a 1/2-1 turns to get the car running right.

Warm up the engine fully. If you can floor the gas pedal from idle and the engine revs without any bog or backfiring then you should have your adjustment fairly close to optimum.

If the engine coughs when floored from idle then richen up the mixture by turning the fuel mixture nuts down.

With the car running and the airfilters removed lift the front carb piston up an inch so that the engine runs as a 3 cylinder on the back three cylinders only.If the engine dies richen up the back carb a 1/4 turn and try again.
Reverse the procedure to check the front carb.
If the engine runs roughly then you are running too rich and need to lean out the mixture.
Make sure your timing is adjusted properly. I have a modified engine and run about 34-36 degrees total advance. If your car is stock you will need less total advance.
Alot of problems people have with their engines missing and bogging is actually caused by their ignition timing being too retarded.

Later,norm

240z

Thanks Norm for the useful information. I have got a couple of problems with my carbs I think which are that when I lift the pin on the 1st carb it does nothing at all. But when I do it on the 2nd carb the engine almost stalls. The timming is at 9-10 degree's on a l28 engine it's got the K+N filters but that's without the vacumm advance connected. I thinks it's around 20 with it on. I think I may need to get a new mixture screw on the second carb it's a bit rounded and when I turn it downwards it get to a point where it moves in the up direction again obvious something is worn. I don't know if you've encountered anything like it before? When you say to file down the throttle shaft between the screws do you mean to file in between the two screws that hold the round object(not sure what it's called but it's like a butterfly sort of thing) on to the shaft? You'll have to forgive my ignorance when it comes to carbs I'm new to everthing to do with cars.
Suprisingly though the car runs quite well it's idle's very smooth but sometimes when it idles it's like it hiccups. Is this to do with valves or carbs settings?
Thanks Again Norm.

-=240z=-

Zrunner

Hey 240z, the hiccups you are referring to is probably just the normal idle stumble that you get with most any carbeurated car. FI cars are much smoother running at idle.

The shaft area between the screws on the throttle plate can be filed down with either a dremel tool or a regular file.
Unless you rev your engine above 6000 rpm and are running a longer than stock duration camshaft, I doubt if there is much point in your doing this mod.

Later,norm