jeffp

Along with harmonics, the damper also absorbs the torsional stresses created by every combustion event in the engine, and that is very important as well.

I dont think the raised part of the chamber in between the valves is going to beneficial. What I would do in stead is to relieve the block and the head like you see on big block chevy engines on the exhaust side. Using a metal head gasket will enable you to open up the exhuast valve flow on the edge of the combustion chamber, then cutting a slight relief in the cylinder, and deck to mirror the relief in the head will improve the flow significantly, then with the other modifications to the port you should reach the numbers you are looking for. The intake side of the head is easily improved with your porting, then use a stainless steel valve that is worked with the valve seat area close to the top of the valve head, remove excess valve area by countouring the valve to a smooth transition to the seat on the valve. That will improve the flow of the intake valve. Now, the lift on the cam, you will want to watch the lift on the exhaust side as increased lift on a ported head tends to hinder flow, but with a good relief in the side of the combustion chamber it may improve. The trick here is to use the valve and the lift to promote an easy exit of the gases, with the relief in the head and the deck, you can use the valve as a base for the exit, then contour the port, to flow with the added opening in the combustion chamber and deck. Do you see what I am talking about? anyway just some of my thoughts.

You outlined almost exactly what I drew on your picture. The second surface acn have material removed as well, making the port the same diameter for a good even flow. The thing is that as exhaust exits the combustion chamber the port will promote a rolling effect of the gases because of the longer radious which will help the exit of the exhaust. Also like I said about the guide, you can take some of the material off and make the guide shorter, but you do run the risk of wearing the guide fast, so if you move the guide up some, you will be able to maintain a longer guide that will make a longer lasting part. I did not see the different materials, and the steel ring in the head is what is holding the guide for the most part, so it should stay in place provided the knurl is a correct debth and size. I think this would work out well, but dont forget about the heat on the exhaust port and especially the heat dissipation.

The idea here is to move the guide up, so .375 would be good. I am not sure about the contact area of the guide to the cylinder head. I would like to see some of the contact area maintained for the exhaust guide by building up weld and then machining the welded area. Its important to remember here that the exhaust valve and guide get much hotter then the intake valve does, so that being said, I am reasoning more contact area would be a safer bet then to just remove all of the material and count on the knurl in the guide to hold it in place with less contact area. One thing to consider is that in my head I am running a exhaust valve that is 1.400 and not the stock 1.380 a slightly bigger valve, but it improves the flow of the exhaust. That big chunk of material in the exhaust port is the key factor hindering flow, so if that can be removed, the guide moved up the suggested .375 then the flow of the port will be improved significantly. Then if you want to go really radical, then have a guide that fits a 7mm valve stem and gain some area that way. I called ISKY and they said they could make a valve spring retainer and locks for a 7mm stem. These modifications will improve the hp output of a turbo application, and it will help out the N/A engine as well. anyway, I am curious to see what the guy is going to suggest for improvements, post some pics James so we can see what he suggests.

I was looking at the exhaust port and guide area and that is a real problem for the head in my opinion. The intake can be done easily enough to get the flow up. The exhaust port on the other hand is a different ball game. I printed the picture of the port and here is a possible solution to improve the flow. The first thing that can be done is to shorten up the guide, but with that you run the risk of a quick failing guide. The thing that occured to me was to move the guide up say 1/2". Weld on the top in the spring area to provide added support for the longer quide. That would have to be figured out just how much weld could be built up so that the spring retainer would not hit, but I think you could get away wil about 1/2" Then machine the weld so that it would not touch the spring and accept the seal. After that is completed then you can remove the chunk of material in the port and still maintain the guide strength so that it will not wear out quickly. That would free up allot of space in the port. then on the lower side of the exit you can remove some of the radious above the water jacket and free up some more space. The question is tho, how much can you build up the valve spring seat area in the head, and would you, and or, how much would you have to shorten the guide. The thing is that even if you did just the intake side of the head, the exhaust side will be the bottle neck and it will gain you nothing if you cant exhaust the same or close to the volume you can take into the intake side of the head. What do you think James? That guide and radious side of the valve guide seat if that could be effectivly removed and keep a strong guide would really improve the flow, if you wanted to keep a close tolerance you could remove enough of the radious and make it the same size diameter as the valve.

The damper significantly reduces the pulsation that occures in the fuel rail from the injectors opening and closing. Without the damper you will have a very hard time getting the fuel management to do its job effectivly. The idea here is to keep as constant pressure at the inlet of the injector as possible so that it will deliver a consistant amount of fuel each time the injector opens. Some of the new cars run two dampers, and I think that is not a bad idea. There is a company that has made a ball type damper that I have considered installing on my car as well. You can find them on the web if you do a search for fuel damper.

I did my setyp with the 6A and the 8910HEI tack adapter. I did not have to run the stock coil to get the tack to work. Very simple to do. You use the stock power transistor, the stock harness, and hook up the tack adapter wires from the (8910HEI) to the black wire and the blue wires. One of the blue wires is for the tack and the other is for the coil. they are connected together on the stock configuration and they stay that way for the MSD box. You use the electronic ignition connector from the MSD box to connect it to the system and it works excellent, very clean. The question of using the MSD box or not, well there again it gives you a few advantages like the multi spark to 3K rpm. You get with the right coil 45,000 volts out of the coil, it is the big blur transformer type coil. I cant remember the name on the coil. The one thing that you will have to do when you start getting up into the higher boost levels is to gap the plugs to .025 because even with the bigger coil, at the higher boost levels you will start getting misfires with the standard plug gap suggested by Nissan. Other then that, the MSD box is an excellent addition to a turbo car and works very well.

I built my system and I was trying to market it through MSA but they said it was to expensive and they would not have the demand for the system. I did before and after data on the car, it was stock and ran good. I dynoed the stock system, then I installed my system and it gained 20-25hp and 20-25 foot pounds of torque. I did list the dyno sheets on my web page at http://www.angelfire.com/extreme/280zxt. I really wanted to sell the system because I knew it would sell, but I could not get any shop to buy a quantity of the complete system. The bender I used, and they are for the most part exclusive, would not one or two system at a time for me. But in answer to your question, yes just changing out the stock system on a stock car will gain you a seat ofthe pants change no question about it. That should clear up your questions.

I went with a slightly different combo for my latest turbo build. I decided on a .70 A/R exhaust turbine housing machined to fit the stage 5 exhaust turbine wheel (ten blade turbine) Then I went a little off the norm with a .60 TO4E compressor housing machined to fit a 62-1 compressor wheel. I think this is going to be a very good high boost combination for my car with the way I configured the bottom end. BUT, I will know for sure the first time I blast the boost and see where it spols up at. I am trying to maintain full boost @ 3000 rpm's and that will be ideal for me. Good for the freeway, and not to bad for around town either, Good for the track, so if my design work operates the way I think it is going to, I will have an excellent combination. I will let everyone know what it turns out like here in a few weeks.

I ran the car without a muffler , not even down the road and with the cat still in the system the noise was at least 50% louder. This was with just the muffler removed and all of the system installed. I did not like the noise level at all.

I just went through getting a cross flow radiator for my 83. I looked at three companies, one of which I cant remember what the name was, but I could not get anyone on the phone so I dropped them as a builder. Griffin radiators are known for their quality and do work well. The one thing that I really did not like about their unit wasthe fact that they use epoxy to seal the end tanks. I realize this works well, but for me I did not want any sealer, glue, or anythhing else used on my radiator except welding to make the part. I found a company CR Racing and they made the radiator to my specifications, all welded parts, not glue of any sort. I am very pleases with the part, and I think it will last a good long time in my car. If you are interested in what they have to offer and talk to someone, give Rob a call at (317) 293-4100, tell him Jeff Priddy sent you. I made sure Rob did a set of drawings on my unit as it will fit any zcar application. The radiator will also support a 600hp engine and provide proper cooling for performance applications as well stock applications. hope that helps.

I received the finished product today from BHJ. The Damper looks sooooooo sweeeeeeeet! This part will put an end to the damper issue associated with the high RPM L series engines. I am taking pictures of the part for the NEXT SportZ issue, so if you want a picture of the part and the specifications of the part you will find them in SportZ magazine. I will tell you one thing tho the part is sweeeeeeeeeeet!

If you are going to machine the bushing on a lathe, then make it a .001 press fit. The bushing will crush down when you do, so the ID of the bushing, after install should be about .0025 clearance for the input shaft. Make sure it is not to lose and that it is not to tight. Both cases will make either a hard shifter, noisy, get stuck in gear, or pop out of gear.

I was having much the same problems you are talking about and tried all of the above, except the new lower hose, that had not occured to me. I was not sure about the temp gauge and wanted to be sure baout it so I went to target and bought a 14.00 dollar digital thermometer and ran the car. I opened up the radiator after I got the car hot and got an exact reading of the temp and it was dead nuts on 190 The car gauge was right at center of the gauge. Then I let it sit in the radiator for a little longer and it went to 198-200 and the gauge in the car went about two needle widths above the center. I did not solve the problem, but I did verify the gauge. I then went to a 180 thermostat and that helped a little, but I was still getting a temp creep at the long lights, but it would come back down as soon as I was on the move. I tried all the various fans, flex, electric, and the stock fan. The stock fan worked the best. Now what I have done is say hell with it and got an aluminum cross flow unit from CR racing, that should cool down the engine and enable the thermostat to do its job correctly. I will find out here in a few days how it works.

I was running a stock manifold that I did a little work on. I port matched the turbo inlet, opened up the exhaust ports somewhat. My last dyno pull got me 413 hp and 475 foot pounds of torque at the wheel. Really, the stock manifold will do just about what ever you want it to do within reason. I have found that if you take the time to port match and open up the inlet to the manifold the part works well. I was just not to sure about getting 600hp from the unit. The other consideration is the waste gate for the turbo, that seems to be a factor in the whole setup. I was running a stock exhaust turbine housing machined for a stage 5 exhaust turbine wheel and it did well. I was @ 20psi of boost by 3K rpm's not to bad. The waste gate in the stock housing was starting to give me a little trouble as I did have a little boost creep at the higher rpm levels, so keep that in mind. Here is the thing I liked about the stock manifold. Being a log type setup, the run to the turbo was short. This plays a significant role in the exhaust gases that are turning the turbine. Keeping the run short will keep the exhaust hot, and the Volume of the exhaust will be more just because there is not all of the long runner to fill before you get it to the turbo. When you start getting the longer run to the turbo, it takes more volume of exhaust to fill and pressurize the inlet of the turbo that will turn the turbine wheel. I am not so sure that there is enough volume in the L28 to properly fill and produce the required exhaust to effectively turn the turbine at the lower rpm levels to get a quick response turbo. Just my thinking here, but like some say, if it isnt broke dont fix it. When I was ready to take the turbo off for a bigger exhaust turbine housing, I decided to do a back pressure test of the system to get an idea of what would change in the system with the bigger A/R exhaust turbine housing. I was very plaesed to find that my back pressure was running 1:1 so at 23 psi of boost @ 7K rpm I was getting 23psi of back pressure @ the inlet of the turbo, this was vary good for any application. So my thinking now is that with the bigger turbo pushing 30-35psi of boost to get me to the 600Hp range, the new setup should be excellent with the .70 A/R exhaust turbine housing machined to 2 1/2", running the stage 5 exhaust turbine wheel. I should never hit the breaking point on the back pressure curve to make the added boost ineffective. The question remains, how fast will the boost come up and at what rpm. I am hoping and thinking that 3K will be right in the ball park for my new build. If I can be at 30psi of boost @ 3k rpm, I will be very happy, and 5k rpm look out, because my engine will be putting out some real power at that point. So that is what I have found with the stock exhaust manifold, my thoughts on the system and how I accomplished my results. hope that helps.

Take a look at a TO4E .50 trim with a stock Nissasn housing machined to accept a stage 5 exhaust turbine wheel. That setup is what I ran, and is what Lockjaw is running on his car now. I got the Hp to 500 hp at the flywheel and the exhaust side was not the problem. I took the time to do a back pressure test on the setup before I took it off the car and I was running 23 psi back pressure for 23psi of boost. You cant get much better then that. Remember this was with a atock Nissan .64 A/R housing machined for the stage 5 wheel. That combination works excellent, keep the internal waste gate, run a stock housing, and build 20psi of boost @ 3000rpm's Good setup!

You are correct the older slider for the 340 is shorter. Use the T5 slider, and I do believe you can use/swap out the throwout bearing I had both of them aitting next to each other at one time, but I cant remember if the contact area was the same on the bearings. That would be what you need to check. But use the T5 parts, and if you have an old adjustable clutch arm with the hole in it, use that setup, and you will be very happy to be able to adjust the clutch arm, and have the return spring as well.

Well I finally got the pan completed and it is in the welder to get all put back together. I did the layout work on it and tacked it together. The scrapers were hitting three rods so I made adjustments in the windage tray for that also. All in all, it has turned out good. I got the holes made for the temp sensor and the turbo oil dump. I should have the pan back Friday, so then it is off to get powder coated and finally installed. The one thing that keeps coming up in my head is the pickup. I noticed they made a pickup that has about a 1" tall pickup cup, but the tube doesn't go to half way or 3/4 the way into the cup, the tube is mounted near the top of the cup. I am not sure if that will be an issue or not, as that will put the pickup tube about 1 1 1/4" from the bottom of the pan. I will have to think about this one for a while.

I just had this part made for me last week. I am running a TKO2 tranny now and I had to have the driveline made for the car. The 300ZXT LSD pinion flange is larger then the standard flange. It uses the 100 blots, but most significant is the fact that Spicer makes a companion flange that will hold a 1310 universal joint, much stronger then anything Nissan made. I have a picture of the driveline and flange on my web page at http://www.angelfire.com/extreme/280zxt/page24.html I also went with the non greasable universal joints which are srtronger still. I dont think you will have a problem with that type setup on your car.

The clutch fork is the same part for the T5, but what I would do is get a fork from an older 240 that has the hole for the adjuster, so you can adjust the throwout bearing. Just go with all of the T5 parts, flywheel, clutch, throwout bearing. I do believe that the tranny mount should also work as well. The only thing that I have heard that was different was the shifter location, but then you can buy the Ford mustang shifter and that will solve that problem. The stock clutch stuff will work for you as far as I know. I have a Turbo diff flange if you need one to use with the driveline.

Hi James, I was looking at your post and the bellhousing looks good. I have a question tho, are you sure the C4 is going to hold up to the abuse you are going to put it through? I have a suggestion, Ford made a C6 that fit the SB application on some of their trucks and vans. The C6 is a much beefier tranny then the C4 is. I have a good friend in Carson City that ownes a Ford junk yard, and he builds trannies. His name is Richard Haas, his number is 775 246-3444, just a thought here, but you might want to give him a call about the C6 application, he can get you one if you would like to go with a stronger tranny that the C6 has to offer. Just something to think about before you get full force into the C4 tranny.

I was thinking of going with the ZF6 in my car and even bought one for the car. That tranny is a monster, and it is not easily installed at all in ANY Zcar. The biggest thing is that the gear set is no on center of the case, it is moved over about 2 inches or so. Then the other thing is that the shifter is also moved over another 2 inces or so. That makes the shifter way to far over to fit the hump, and even into the seat area. The case will hit the hump on the left side so it will have to be cut, so juust to get the thing into the car you will have to hack the heck out of your car and figure out a way to change the shifter, and then it to is sloppy shifting. Then you have to figure out the clutch, the driveline, the tranny mount and the clutch, pilet bushing. I WOULD NOT RECOMMEND TRYING THIS TRANNY, there is just to much to change to get it to fit, and then they have a problem with second gear going out. If you want the best bang for your buck, go with a tremec TKO or TKO2 tranny. They are by far the easiest tranny to get installed in the car and they are strong, stronger then the T56. I was going to do the T56 tranny, but there again, there were so many more mods to do, and the part that really bothered me was that the input spline/shaft was 1" to short and required to have the pilet bushing/bearing installed in the flywheel. I did not like that idea to much. I did like the gear ratios that the T56 had to offer for the car, but that was about it. There is a guy that has done the bell housing, Virgel Plunk, but I dont have his number anymore. He wanted about 600.00 to do the bell housing. I have installed a TKO2 in my car, and you can see what I have done at my web page at http://www.angelfire.com/extreme/280zxt/page24.html and I have a number of pictures of the tranny and everything I have done to get it in my car. hope that helpes.

I called yesterday about the build and did not get a call back from Frank. I called again today and am waiting for a call from him. I will call again after lunch and see if I can get him on the phone.

Hi Tim, I cant remember which pin gets the ground. I am assuming you are using a DB9 connector off of your pc. But from the PC connector say pin2 is the receive, then it goes to the transmit pin on the eprom, and say pin3 on the PC is the transmit, then the eprom end of the wire goes to the receive. You need to make sure the transmit and receive lines are swapped in order for the comm to work. Transmit from the Eprom goes to the receive on the pc, and the receive on the eprom goes to the transmit on the PC. If the two wires are not swapped then you will be have the transmit line going into the transmit line on the other end. I dont have the schematic of the megasquirt so I am not sure if it is swown or not. Hope that makes it clear to you, and if you have already done this then you may have a bad setup or megasquirt. BTY what software are you using to program the megasquirt? Did they give you software to use for programing? or are you using something like procomm or procomm plus?