Scottie-GNZ

If that is the original wastegate cannister, I would check the diaphragm. Only way I know is to use some sort of a pump and put pressure to it and watch for the rod to move. Make certain when you adjust the rod that you disconnect it from the lever to relieve the sring preload, else you can damage the diaphragm.

My car is a 71 and the a/c was removed eons ago. Only thing on my engine is the alternator. I am using a simple custom-made bracket to let it sit lower than normal and using Heim joints for adjustability. If you look at the 2nd pic on the top row in my site you can get a glimpse of the alt bracket. I can help you make one if you wish.

Phil, if you are running the stock roadster diff, the ratio is probably too low for the turbo Buick. The Buick is not a high revver, unless you made mods to make it so. The turbo loves to have time in each gear to spool up. I believe the roadsters might have the R-160, but even if it is an R-180, the ratios will probably be 3.70 or 3.90. You can get R-160 LSDs from any Subaru AWD (not 4WD) but they also have 3.70. I would imagine you are running a short tire which makes it even worse. If you have not already though of it, you might consider a 240Z/260Z manual-shift R-180 with the 3.36. No shortage of those puppies . I do not, however, know how involved that swap would be.

Mike, did you ever determine what caused that one to not work?

Robert, before you go spending any money or doing something radical, check some of the obvious things that could contribute to the problem. Timing, Radiator cap, water pump, loose belt, faulty thermostat, blockage in the radiator or block. The Camaro rad should work but is more efficient with a shroud. The Griffin works, but I would hate to see you switch if there was another problem. As for placing things in front of the radiator, no doubt anything in front could potentially cause blockage but here is living proof of how good the Griffin is. Notice there is a big oil cooler, trans cooler and, ahem, a fair sized I/C, ALL not only blocking the air to the radiator, but heating it up. In the FL 90+* & 90+% humidity, I rarely go over 185*. I run a 160* thermostat, 10+% anti-freeze, a bottle each of WaterWetter and RMI-25. I use a 16" shrouded electric fan from origins unknown that I got from the boneyard. $188 shipped, one of the best bargains out there. [ July 17, 2001: Message edited by: Scottie-GNZ ]

Read this article on the engineering GM put into the 3800SC engine. GM 3800SC Tech Article

I stated a couple of days ago that if there was enough demand, minimum 10 pairs, that I would work with the machinist to do another run. I expect a slight increase in the cost of making them and considering some of the other adaptors I see being made (rear disc brakes, e.g.), the price SHOULD be in the $145/pr. I have not and probably will not speak with the machinist until I see that there is enough interest. If memory serves me right, I recall 3 up to this point. [ July 16, 2001: Message edited by: Scottie-GNZ ]

quote JohnC, your statement is accurate except that it leaves out a little detail on the assembly. It is my understanding that all LSDs and the NISMO R&P uses a 12mm bolt and the non-LSD units use a 10mm bolt. Therefore, bolting up an OEM non-LSD R&P to an LSD requires machine work. Either the LSD has to sleeved or the R&P bolt holes need to be opened up to 12mm. I personally have not confirmed this but this is the word I have gotten from 2 folks who have put 3.36 and 3.54 non-LSD R&Ps on OEM & NISMO LSDs.

Update. Got an email from Morgan asking the same thing. I sent him advance and retard maps and he said it really woke his car up. MOF, he said he added a little more advance and the car felt even stronger. Use my numbers as a guideline and adjust accordingly. You might all have have L28Ts but believe me, there are so many variables, every engine will react differently. Turbo size, gas quality, I/C efficiency, exhaust backpresure, etc, all play a little part in making the engines react differently. The SDS has a great tuning feature, the R/L knob. Learn to use it and you will be rewarded. E.g., if you sense a ltlle knock, richen the mixture and see if the knock goes away. If it does, then you have 2 choices, more fuel or less timing. If you have an A/F meter, it can help with that decision. Tim, I would say you are probably a little conservative, BUT, I follow the low-timing/high-boost philosophy myself but never run high boost w/o the most octane I can get. Why I say it might be conservative is that on the street, you only do short bursts of high-boost in 3rd or 4th gears and that is where the real load is, so you can get away with a little more timing.

Davo, send me an email.

Here is what worked for me and Patrick. Build an ignition curve that starts at 20* at idle and ramps up to 39* by about 3300, then take 39* up to redline. Then build a retard curve that starts at about 2# boost (whatever is close) and ramp it up to 15* retard at 15# boost (assuming you have a 2-bar). The goal is to have the quick advance to match the boost coming in early and to not runmore than 24* total (advance - retard) at 15# boost. If you want less timing, start at 20* and ramp up to less than 39* or make the numbers in the retard map larger.

If you are referring to the R-200 diff, the LSDs only came with 3.70 in 87-89 300ZXT (might be off on the years). If you want a 3.54 LSD or any other ratios, you have to get the LSD diff and the R&P or a diff with the R&P and put the R&P on the LSD diff. It will require machine work unless the R&P from NISMO.

Lone, the Ford 8.8 IRS is still an option for me. However, I spoke with Marty (sp?) at Raxles and he sells new HD 1.5" CVs for them at $500/pr! What I do not have is a list showing what vehicles came with what ratio. I know most of the T-Birds had a 2.73:1 and that is too tall. I know we can get these for a resonable price but if you have to cough up $500 for CVs, then also have to get a R&P and have it setup, it could get pricey. Keep us informed on whatever you find out. Here is another good pic of that complete unit.

If my math is correct, 94*C is 201+*F. I would be concerned about the air temp coming out of the compressor at full boost. It depends on how much boost and how lean you run but I am not sure PVC and the glue will hold up well to that type of temp.

KraZ4spd, if you or anyone else decide to go welded 3.54 for drag racing, I just pulled mine out. That is the one I have been running and will be dropping in a 3.36 to experiment, then on to something strong enough for me to run more power and slicks. If anyone are interested, you can have it cheap if you are willing to pay shipping AND you understand caveats of a welded diff.

Ashe, welcome. If you want to know the real pros/cons of a hybridZ, you have come to the right place. We are living it. There is not much that can be added to the great responses you have already gotten. As for the V-6 turbos, they are torque monsters. When you get them up in the 400RWHP range, they are equivalent to a healthy big block with torque exceeding 500 lb/ft. With the right combo of OEM parts, you can have an IRS that will withstand that power. There are enough lessons learned here that you will not have to experiment or re-invent the wheel. Leave that to the some the pioneers here

John, I have no reason to doubt your parts man and maybe it is possible that The number has changed or is being re-used. When I wrote that little How-To, the part # was taken off the box that the brackets came in.

There is indeed a bit of confusion in this thread. Let me see if I can help clarify some of it. Z_Ferrari When I referred to the ID of the line being the problem I had, I was referring to line that is the source for the wastegate actuator, not the I/C pipes. IMO, the pipes you have are a bit small considering you are running an upgraded turbo. I will repeat what both Tim and I have said about what we think is the problem. Based on the symptoms, it appears the wastegate is not functioning, ie, it is staying shut. I already gave you 3 reasons why that could happen and I caution you to find the problem before you continue running the car. The kind of boost you could potential see in 3rd or 4th with stock injs and pump gas is asking for trouble. Shortening the wastegate rod is a tried and trued method of adjusting boost, but there are some caveats. Do not use it to get more than about 6# boost increase. 1 full turn usually equates to 1# boost. When you shorten the rod you are preloading the spring in the wastegate cannister. The stock spring pressure and the length of the rod are the keys to the pre-set wastegate actuation. Pre-loading the spring by shortening the rod requires more boost against the diaphragm to move the rod. The more you shorten the rod, the more you have pull against the spring to put it back on the lever. Shortening it too much will reduce the rod travel and worse, cause the spring to bind. ANOTHER CAUTION, do not turn the rod while it is still connected with tension on it as that will destroy the diaphragm. SleeperZ I use a combination of a bleeder valve and an adjustable wastegate rod to go from the stock 12# wastegate setting to the 23-24# I run at the track. This is my latest procedure. I use the bleeder valve to go from 12# to about 20#, then the adjustable rod to go above that and do any adjustments at the track. When I am on the street, I disconnect the bleeder valve, and cap the line , and have about 15-16# on the street. DRAX Yes, the spring method is pretty neat also and puzzled why others do not try it. Hope I did not throw more mud in the pond.

Late model Supra TT, 6-spd.

Scotty, if you are running a t3/t04, then you should be using an adjustable wastegate rod so you can up the boost to recover the boost lost from the pressure drop in the I/C and take advantage of that bigger turbo. IMO, it really does not matter whether the source for the wastegate is coming from the compressor or the intake. What is important is that the reference point for the boost gauge comes from the intake. MOF, I think you get a more consistent source for the wastegate from the compressor and if the rod is adjustable, you adjust the boost accordingly until the gauge tells you that you are getting the desired boost at the intake. I had a similar problem with my L28T and it ended up being the ID of the line that caused the problem. BTW, the Buicks have the wastegate source off the compressor with a restrictor in the line. Think carefully about what is actually happening. Boost pushes against a diaphragm in the cannister which pulls the rod away from the turbo, pulling the lever which opens the wastegate puck. The less the puck opens, the less boost gets bled off, the more boost will be produced. With the source at the compressor, the diaphragm should be seeing higher boost making it easier to open the puck. Instead, as you put more load on the engine in the upper gears, the boost keeps going up which means the puck is not opening as much as it should. To me that means 1 of 3 things. - There is a restriction in the source line - The diaphragm is bad - The wastegate puck is stuck and not swinging open freely. Disconnect the wastegate rod and make sure the puck moves the puck freely. Every serious turbo owner should own a MityVac. If you had one, you would connect it to the wastegate and pump it up and as it increases the pressure (like boost) you should see the wastegate rod get pulled into the cannister. If it does not, then the diaphragm is probably torn. If the those are OK, check the source line and then try different ID lines. Vacuum lines are cheap. BTW, any boost testing should be done in 3rd because it puts more load on the engine and you have more time to react if the boost goes off the scale. [ July 08, 2001: Message edited by: Scottie-GNZ ]

Scott, I used the NPR in my L28T. Look here: http://www.zdriver.com/members/scottiegnz/icmods.html

You can certainly buy all the parts to make one but the price would be astronomical, for me anyway. You would need to find a 300ZXT LSD and if you can find one it will run you at least $400. Next you need the 3.36 R&P from a R-200 and can you say "Hen's teeeth"? Or you buy the one Ross C has for sale for $300+ship. BTW, I will be be freeing up one soon, but more on that later. If you cannot find a 300ZXT LSD, then you can buy one from NISMO for about $800 and it is a much better unit. You either have to sleeve the LSD for the smaller bolts used in the R&P or drill and tap the R&P for the larger bolts used in the LSD. All new bearings and a driveline shop to do it right and you well into 4-figures. Kinda makes you wonder why some of us are looking into alternatives, huh? I have an R-200 3.36 in the mail that I will use for a short while until I get my final setup, what ever that is. It supposedly makes a slight whine, but will suit my purpose of drag racing for a while. After that it will become available but it will be welded. Had a close look at a late Supra rear suspension yesterday. It is a nice compact setup and with a little "fabrication" , I can make it fit. Probably too wide to fit under the stock Z fenders. It measures 67" from the outside edge of the tires and that is with 17x9.5" wheels with 245 tires. That is only 1" wider than what I have today! I was just salivating when I saw the configuration, with aluminum arms, 12+" brakes, 3.133 LSD and guaranteed to be lighter than the Nissan IRS. Now I just have to find one . If not, I will go with a Ford 8.8 as nothing else has the ratios I need. [ July 07, 2001: Message edited by: Scottie-GNZ ]

If the engine is in good condition, you will save a ton by not even having to remove the head. An efficient I/C with mandrel bent piping, low-cost t3/t04 upgrade turbo, upgrade DP and/or 3" exhaust, low-cost inj upgrade (check my site for the SVO mod). To keep the cost down you will have to know how to "fiddle" with the AFM to get the proper mixture. I made 300RWHP running 17# boost with the stock T3 turbo. The engine was untouched, and I had an NPR I/C, my own DP with 3" exhaust, SVO 370cc injs, 300ZX 55mm TB, and SDS. I would not recommend trying to push the stock turbo that far. A low-cost t3/t04 upgrade is only $400+ and worth every penny. My buddy is makingh 350RWHP with a Spearco, bigger injs and turbo. The SDS tends to blow everyone's budget but you end up doing so much fiddling w/o it. It is so nice to not only have control of the fuel but timing advance AND retard. Check out DRAX's site and mine for tips. http://members.home.net/drax77/newpage.html http://www.zdriver.com/members/scottiegnz/scotties240zt.htm

By my calculation, 164.6mph with a 24.75 tire. I use the following formula: (tire diam * 2.905) / (diff ratio * trans ratio) = MPH per 1000 RPM

Lone, you got the idea. The difference between my solution and a solid diff mount is that the stock rubber mount is still in place to absorb vibrations. Since no one else is using it, folks have to take my word for it that there is no vibration or resonance like you get from a solid mount. My Z does not have a radio and those 4-500 mile highway trips lets me hear evey sound in the car and the rear end is not one of them. That was a good point about a bad rear end hightening the problem of a solid diff mount. You could also put in a pair of 2-chamber Flowmasters if the rear end noise bothers you. My apologies (sympathy) to those who have them .