SHO-Z

I think the guy in Oregon that sells the New version of the SK racing carbs has them, but they are not cheap. With all of the information it this thread, go to the next leval or fab your own. http://forums.hybridz.org/showthread.php?t=127863

I stand corrected. I was just using the picture that I have.

I do not know if the SK racing and the TWM are copies. Here is a picture of the SK Racing carbs that I have. The carbs came from TWM from the little tabs that were on them when i bought them used. I do not think there is any marking on the maniflold.

There would be little difference between a targa and a convertible. You have to reinforce the chassis and where the top is cut. The cross supports for the top is the windshield and the hatch hinge area.

I got these off of ebay they are off of a camaro and are installed on the back side and molded in. They were a pain to get installed and not crack at the edges.

Here is an air box that will work. http://www.twminduction.com/airbox.htm They use to sell SK Racing and webers Here is a picture of my air box These are SK Racing carbs. It is set up for blow through supercharger

I would see my Z to anyone who has the cash! If he wanted to drive it in a demo derby I could care less. After it's gone it's gone, the new owner can do what they want. The only time I would have any feelings is if I saw it drive by and that could be both good and bad, it all matters if it was being taken care of.

I found this when I was looking at installing a SHO in my Z. By his write up a 2.5 is as large as you want. John Holowczak on Exhaust Design January 18, 1998 -------------------------------------------------------------------------------- The following are some comments and observations on exhaust system design that I've absorbed over the years, as applied to the SHO. Hopefully they will provide some meaningful guidance to any of you that are pondering designing your own custom system. I welcome any input or debate anyone wants to make here, other than the "Doug sez they rattle" or "Ted sez they're better in his book so it must be so" dual vs single debate we've heard too much about. All of the below is IMHO, and FWIW, I do not design exhaust systems for a living. First off, the ability of one pipe vs another to flow gas can be roughly approximated by their cross section areas (a paper towel roll being easier to exhale through than a straw, for example). For a stock SHO, as well as the Contour SVT 2.5 liter, the intermediate pipe is 2.25 inch in diameter, for an area of 4.0 square inches. For a 5.0 H.O. in a Mustang, dual 2.25 inch pipes are used for an area of about 8 square inches. The interesting thing about these two comparisons is that the SVT has a high winding 2.5 liter DOHC engine, similar in some respects to the SHO engine, but with lower peak horsepower. The engineers at SVT felt a single 2.25 inch pipe was ideal for high peak power, without reversion hurting low end torque. If true, the larger 3.0 liter SHO engine should need a 2.5 inch intermediate pipe (area of 4.9 square inches, 22% increase) for its 20% higher displacement, and 13% higher peak HP. The Mustang engine is added here because its factory exhaust is often noted for having very low backpressure for an unmodified 5.0l V8 engine, and because its peak horsepower is equal to the SHOs, or very close. In order to effectively burn enough fuel/air to make 215 to 220 hp, the Mustang has double the rough exhaust flow capacity of the SHO engine, even though, at peak hp, the amount of fuel/air consumed is roughly the same. The reason for this difference in size has to do with reversion, which is back flow of the burned exhaust gases back into the engine. The bigger that the pipes get, the better the chance that flow can reverse and contaminate the incoming fresh air/fuel charge. On a Mustang, the large displacement keeps the total volume of gas going though the exhaust high (at low rpm), and a moderate amount of reversion is even desirable to help reduce peak cylinder temperatures and keep NOx down (the 5.0 having a basic layout and chamber design that is not ideal from an emissions standpoint). With the smaller displacement, bone stock SHO engine, dual 2.25 inch pipes would likely allow too much reversion at low RPMs, hurting low rpm torque. This latter effect can only be mitigated somewhat through additional fuel/spark a la an LPM, but it can not be eliminated completely, irregardless of what you may hear elsewhere

The cam spins at half the speed of the crank.

Old School Method, At idle remove one spark plug wire at a time. If the noise goes way or changes it is a rod.

Any changes of direction will restrict air flow. Back in the day when these cars were new the guys racing them were not installing 4 barrels for racing, they would go with side draft webers or larger SUs. I really do not have anything against 4 barrels on Zs, but why are down draft webers considered junk? Heck all they are is a 2 piece 4 barrel. I have a set on my z and would much rather have a set of SUs.

If I remember right the electric pump only runs while starting the engine and is tied into the hot wire to the starter solenoid. My Z sits for months at a time. I have an electric pump back by the tank and have a separate switch to recharge the fuel system so the engine does not have to crank forever to start.

I did a conversion from R12 to Freeze 12 on my 91 4runner, got it off of Ebay. Before every year had to add a can of R12, a year later it is still working an blowing cold air. Did not have to change anything, evacuated system, added a can of oil in kit and the Freeze 12. I am happy with the stuff. I just thought I would let everyone know of another way to go.

Congrats, but is it really motocross, heck back in the day there were 3 motos to race, every track had a water hazard, corners were not all bermed, jumps were not as big and important, 5 inch suspension in the front and 3 in the back, hand on helmet starts, and the bikes were bultaco, montesa, greeves, ajs, maico, cz, husky, sachs, penton, you could race and win on a stock bike. Shows how old I was when I raced motocross.

Also watch the fluid it makes great paint remover so watch were you blow the stuff out too.

I know that 2" will flow the air but you are leaving HP on the table. The less pressure loss in the system the more HP out of the engine. Depending on your engine you could be leaving 10 to 20 or more hp.

Old engines like thick oil. On old engines I run 20 50 oil. Had a Blazer years back use 10 40 and went through a quart every 1000 miles, 20 50 every 3000 miles or ever oil change. This was probibly due to valve seals on that engine.

Ok lets look at it this way if you have around 6 elbows on each side of the intercooler and 10 ft of run piping gives an equivalant length of about 60 ft of pipe. At 15 psi of boost at 6000 RPM gives the following pressure drop between the turbo and the intake. This does not include the intercooler loss. 2" Pipe 1.78 psi 2.5" Pipe 0.54 psi 3" Pipe 0.21 psi It looks like 2.5" should be the optinal size for low turbo lag and pressure loss in most cases.

Try this calculator it will give you an idea of the flow looses in various pipe sizes. I know it is for hose but it will work the same. Every elbow needs to be added in ft of pipe. A 90 is about 3 ft if I remember right. Use your max RPM to calculate the CFM at your boost pressure. http://www.gates.com/industrial/pressure/airflow.cfm?location_id=3043

I found one at a plumbing supply store that will work. I didn't buy it but need to get back and get it soon. It as a real low pressure loss across it. If I get a chance I will get the make and model #.

Due to back problems I have not worked on it at all. I have decided to sell the Z and get a Z32, old man car.

Right now I am thinking about selling it, have a bad back and is no longer fun to work on. There is some added shaking in the hood area that could be corrected with a 3 way strut brace. There is no problem with the windshield, it is heck for stout, no flexing at all. I tied the rear struts together when I used the roof section for the trunk. If you look in my photos I used what is in the drawing to stiffen the chassis. If your 260 is a clean small bumper, keep the top on. If it is a semi abused large bumper 260 get a marker out and a 6 pack and start cutting after you install the reinforcement. Have fun either way!

Here is my write up on doing one. I do not have any lateral stability problem. The car lacks torsional stability, I can feel it flex on hard turning. I need to add an "X" brace tied to the 1x2 tube stock that I installed. Heck I have not put 500 miles on the car since I finished it 2 years ago and in mosty somewhere to stack stuff on in the garage anymore. This conversion was done similar to the Z Therapy conversion. I collected through the internet and several Kit Car Magazine articles my plan of attack on the conversion. First I would not do this to a real clean Z, there are enough ones out there with minimal rust and body damage around. This is a general summery of how I constructed my project. Step One Sit down with a couple of beers and think this project out, once you get to Step Two there is no turning back. Remove the entire interior from the doors back and the head liner. Jack the z up level and put the stands on the suspension points. Evan though the car is still a coupe I wanted to make sure that when I added the reinforcement the car was still square. Install the 2” x 1” x 1/8” tube stock under the car, behind the seats and through the floor. The use of a protractor square helps in laying out the angle cuts. I added additional welded tabs tying the tube stock into the existing uni-body frame rails. This does limit the seat travel for some one well over 6 ft. Evan with this there is still some torsional deflection in the car. I am planning in installing an X brace between the frame rails to elevate the problem. After doing this conversion I do not believe anyone who says that no reinforcement is required. Remove the rear hatch and side rear windows, Step Two Now comes the lump in your stomach. Layout a line about 1-1/2” back from the top of the windshield. Then another line from the back corner each of the rear windows to the around 2” from the back of the car. I used both a sawsall and a 4” grinder with a thin wheel to do the cutting. Basically cut on the lines lines, some blocking is required to keep things from binding. Once the top is removed cut the top again just off of where the top and the hatch hinges box section. Trim all of the excess metal from the sides of the hatch area. Remembering to leave enough metal to weld too. I set hatch hinge box section directly over the rear strut towers, leaving just enough room to get a box end wrench on the strut nuts. This will get you the length of the trunk and a hard point for the rear shape of the Z. This is the first section of the car that I welded in place. Welding the box section onto the strut towers is like adding a strut brace and I feel really helps stiffen the car. At this point the edges of the trunk were basically installed. This gives a basic arch across the back of the car. I cut out cardboard templates of all of the three sections that need to be filled in. Two for each side and one for behind the driver compartment. I used 10 gauge sheet steel for my added body work. This is trial and error situation but with the cardboard templates it just takes time. I added ¼” angle iron around the rear lip of the driver’s compartment for stiffness. The radius was bent around a piece of plywood after I heated the angle iron. After all of the basic sheet metal was installed and welded in I fabricated and installed a piece of sheet steel for the bulkhead between the driver’s compartment and the trunk. On both the lower lip I installed ¼” angle and one across the center. The upper end had extended 1” tabs every 5” that were bent over. Holes drilled through the sheet metal behind the driver’s compartment were used to weld the upper end of the trunk bulkhead in place. The rear hatch was cut and shortened in the widow section. I used a 1x2 piece of wood inside of each side to align the hatch and welded it back together. The widow section was filled with sheet steel from the original top with and added angle iron brace from below. The latch end of the hatch lid needs to be modified to clear the back edge off truck. I used a remote trunk latch from a Lancer mounted under the drivers seat. On the windshield header I cut slots about every inch or so with a grinder. These are bent down and tack welded to the windshield frame. Square cut and cap off the ends of the windshield posts. This gives a flat top to the windshield and will make fitting a soft too easier. This will basically finish all of the metal work. Now comes the pain of the body work. Looking back if I did this again I would use some of the new fillers with glass in it. One trick I did learn is using a long board sander to flatten and shape the trunk. I used a 2x12 that I cut to fit long board sander paper, glued on some old rubber sheet that I had and just stapled the sandpaper to end ends. It worked great flatting and smoothing the trunk and large surfaces. I have a top frame for a TR7 convertible that I need to modify to fit my Z. The design that I used does not allow for the top to be folded down. John Washington makes a fiberglass top that could probably be modified to work. Seat belts are from an Acura Integra, 3 point using bolt points on the inside body panel. This is the basics for building z convertible. Lessons learned: I would fiberglass the rear trunk lid instead of adding the steel window filler section, I was never happy about how this worked out. Use fiber filled body filler and less Bondo. Start with a Z that was in a little better shape than I had, found more rust around the rear edge of the hatch on both sides. Use a quality MIG welder. The one I used was borrowed and I fought the thing from day one. One weld would be great the next looked like ♥♥♥♥. Maybe I should have had a few more beers put my money into more HP, GTO kit, instead of no top. Trial fit everything at least two the three times to avoid mistakes. Do not hit a truck tire carcass on the freeway on your first day out, it can do a number on the front fender if hit just right. Would I do it again, I really do not know. This is a good exercise in Look at my photos http://album.hybridz.org/showgallery.php?cat=500&ppuser=8660

I would stick with the SUs, I have weber DVGs on my car and am not impressed. Bought them at a wrecking yard cheap and took off my flat tops and traded them off. I would have been much further ahead if I would have put round tops on it. If I come across a set of round top SUs cheap I would buy them and get rid of the webers. Of course what I need to do is install the tripple SKs that have been sitting on my bench for the last few years.