Doug71zt

So, on a low-compression turbo engine with a P90, you don't stand much o f a chance of getting good quench with flat-tops anyway, especially on a stroked and overbored 3.0l. The chamber volume would be too small to get 8-8.5:1 without putting in a 2mm HG, or doing the same thing by putting the piston down the bore. Even if I open up the head diameter to 87mm (my bore size) and notch the bore, I don't think that I would be able to get the chamber volume required to bring the piston that close to the head. Theoretically, the N-series head would be worse for this application, as the chamber is even smaller. I welcome anyone's theory on this. Doug PS-jmortensen - Thanks for the quote.

Proud - It comes up in that context in translations from Chinese and Japanese fairly frequently. It made me scratch my head the first time I came across it. In theory - How close do the piston and head have to be to get good quench action? In my 3.0l, the pistons are flat-top, but a little way down the bore to achieve 8.5ish:1 ratio with the P90 head. Doug

Cody - I have a 87-89 Z31 turbo tranny which is very similar to the Z32 and skyline GTS-T, GT-R unit. It uses a huge output shaft and Ujoints compared to the early Z one. It also has double-cone syncros on 2nd and possibly 3rd gear(I can't remember). If I can't rework an L-series front housing to mount it up, I will probably mill the VG30 flange off of the bellhousing and weld an L-series flange in it's place. It has an integral shifter, and shifts much better than the early trannies. KY- I have gone through a set of 245/50/16 Nitto 555R DR's and they will hook up well When Heated UP. They are no good when they are cold. But, they don't last real long when you fry them every run. When I go to the track, I generally make 20-40 passes a night. It turns out that the slicks are more economical, because they are cheaper to buy in Canada and they last a lot longer. I only have to give them a little spin to get the crap off and they are good-to-go. I just have to get down to it and make a hoop that mounts on the back of the tranny, so I don't have to drill the floor/move my 3inch exhaust, etc. to get a standard hoop in there. I'm not worried about the rear ujoint, as the DS won't drop past my sway bar anyway (custom shaft). Wigen - It's not hard to slip that clutch - It's just that it won't hook up if you slip it off the line. I have to pretty much dump it, in order for it to hook. I don't think that I'm overpowering it, it is a Z31T/Z32NA clutch and 'allegedly' good for the HP I'm putting down. After owning 3 CF clutches over the years, I haven't been happy with any of them. Enough. They are very street-able, but they just won't take the abuse. Time for something industrial-grade. Especially with the new 3.0 and GT-series turbo. I can't wait for next spring. I'm going to end up with something very close to Speeder's engine, but (no offense) in a car a little bit lighter. . BTW- Speeder - have you run your car at the strip since the new engine install? Doug

KY - They tossed me last time out for running 26x9.5x16 slicks with no driveshaft hoop. Wigen - I have a CF DF 240mm clutch in there right now, and it doesn't handle slippage very well. It will be replaced with a Clutch Specialites or ACT unit this winter when the new 3.0 goes in. Along with a Z31 tranny and a lightened 240mm flywheel. My 2nd gear syncro is hurting bad. Also - I assume that you are launching on 15 inch rubber - correct? I'm running 17" with a short/stiff sidewall. They seem to either hook with minimal slippage or spin. I haven't been able to find that sweet spot in between yet. It may run better with a 3.54 LSD than the 3.70 that is in there now, I will find out next spring... FWIW - I was racing a couple Talons for a lot of the night. (25+ passes). They could always get the jump, but 3rd gear seemed to reel them in just fine. It seems like nothing eats up the midtrack like a Z.

I believe that the cold start inj. is only 170cc/min. Kind of a drop in the bucket. My old BAE 280z had it wired to a hobbs switch to come on a 5 psi. Evidently it was not enough, as the engine had 3 different bore sizes when I bought it with (another) melted piston.

I had a chance to compare the performance of my car at the strip with .63 stage 3 and .82 stage 3 exhaust housings. Now here is the important part - With 225/45/17 street tires. With the .63 housing, the car will launch at 3.5-4K and not bog - boost comes up quick and it will go 2.1 60's. With the .82 housing - it will bog and take a little while to recover. 2.4-2.6 60' times. BadBadBad. It is making more HP at the top end - because the ET only drops .2 (IE - 12.6-12.7 to 12.8-12.9). With the .82 housing - if I try to launch on boost, it will BLOW the tires away. If I short-shift to 2nd, it will blow them away again and get all squirrelly. Now if I run the slicks, this will all change because it will go 1.7-1.8 on slicks all day. And launching on the boost won't be a problem. But - I got tossed off the track for no DS hoop, so no slicks until I get a hoop.... As for trap speed, with 13 psi on 91 pump gas, it will now go 115-116. Before with the .63 housing, I had to run 15-16 psi on 94 pump gas to get 116. It will go faster with better fuel, as I had to pull some timing to stop the knock. If I could just get my sh*t together all at once, I know it will run in the 11s now.

Sean - You may want to call V-B and see if they will do a spline count and OD check on the 88SE shafts for you. Then you can measure up your diff and make sure before smacking down the cash. I'm interested in this also, because I have a Z32 N/A diff sitting in the shop doing nothing right now.

Oh - now that brings back bad memories... My 70's metal fan ended up sticking one blade right through the hood, and then the rest of the fan ate the rad... How did this happen, you may ask - missed the 3rd gear shift when racing one of those bitch'in new 5.0 mustangs in 1986. T-stone - welcome to the crew. Chances are you're not going to recover from this with a 12-step program. I'm afraid that the condition is terminal.... Welcome Doug

Well, on the bike it scared the crap out of me the first time it opened. Then again, the dump pipe is about 4 inches from the WG and it is right at your right toes. Actually - The bike just generally scared the crap out of me. 224 rwhp with no extended swingarm. It kind of re-calibrates your whole perception of what is quick. I owned a GPZ 750 Turbo back in the 80's - not even in the same league. Doug

I am looking to order a set of tulips for the L28 manifold I'm building, but I'm overseas at work and can't remember the ID of the runners. Can anyone help me out? Thanks - Doug

I fought with boost creep/instability with the ford/turbonetics internal WG for a couple years. I solved the problem with a Tial 38mm external gate that is now bolted to my turbine housing. I bought a 5 bolt SS flange and bored out the WG hole to the same ID as 1.5" SS thinwall pipe. A 45 deg bend and a little piece of straight pipe and Voila - no more WG problems. With the 38mm gate - I can run any boost pressure without instability or creep. It will clear the stock intake manifold and I have it routed back into the DP, but you could run it open to the atmosphere. Having driven a friends GSXR1000 with a ball-bearing GT25 and an open dump, no way is that going to happen in my car. Even with a helmet on - it makes a pile of racket. We won't even mention his bosses 'Busa with 540 rwhp (GT3040). I can post pics if you like, but I am overseas for 5 more weeks, so it will be a while. It is a less-costly way to go external and involves less work, IMHO. Doug

POP-Rivets are non-structural only. You need a solid-core rivet to stand structural loads. All aircraft structure is riveted - we order rivets by the pound and there are thousands in a pound. Many aircraft alloys are non-weldable, and welded structure is not as easily inspected as a riveted structure. The trail of fretted alumimun "smoke" is easy to spot, whereas a crack in a seam weld is hard to see. As previously stated, aircraft flex A LOT. Riveted structure quite tolerant of flex. Structural repair is relatively easy in riveted structure, not so in welded structure. For a unit-body car, Seam-welding is the ultimate, but has trade-offs. If you prang it, it prangs the whole car, and it won't be as easy a fix. I seam-welded my strut towers and around the upper rear hatch area and A-pillar. Funny, my interior still creaks over large transitions. As for riveting seams in the car, you would be using monel rivets, and as someone who does structural repairs using monel rivets, I wouldn't recommend it. They are hard to pound correctly. Buy a mig welder and develop a useful skill. Hope this helps Doug

Late 80's 200sx 4.11 gears fit, not sure about the truck stuff, some of the trucks were H190.

Hey Jeff - Similar story on the disc hub/ flywheel bolts interference here. They sent you a 300ZX turbo disc. The offset of the hub is different than the 280zx turbo disc. The damper springs touch the flywheel bolts on the L6 flywheel. The V6 flywheel has a deep depressed area in the center of the flywheel, so it will work with a center-hung damper assy, whereas the L6 flywheel is quite flat and requires an offset damper assy on the clutch disc. I also was quite careful on my break-in of the clutch, as I put probably 1500 miles on the car doing EFI tuning, etc before taking it to the strip for the first time. The flywheel was in excellent shape and freshly ground and balanced when the clutch was installed. I have had 2 other CF clutches with the similar story, I just thought that I was over-powering them, but I suspect that they don't live up to their rating system. I'll be looking elsewere for my next clutch. Right now I just dump it at 4K and deal with the bog and 1.9-2.2 60 ft times. It probably has 200 passes on it like this, and seems to work OK in this manner. But if you try to slip it to maintain traction, it will NEVER hook up when the engine starts making good power. I've been through the T/O system and nothing is sticking there. I've just come to the (justifiable) conclusion that they don't work as advertised. Doug

Z32 TT use a CV joint on the diff end of the driveshaft with the R230 rear end. Seems to work OK in that application. Doug

The road racing guys may have to step in on this one, But my car had more push (understeer) with the LSD.It does change the handling of the car. But that can be compensated for with tire pressures, sway bars, etc. Even upgrading to a 4 pinion open diff will be better, as we know that the R200's weak point is the spider gears. Doubling them up will make a big difference in how much abuse the diff will handle. I've never heard of any other mode of failure in the R200. The only problem is the choice of ratios available with the 12mm Ring gear late R200's - 3.7 and 3.9 are common. Doug

Late 86 and newer Z31 have 4-pinion diffs from the factory(or LSD). Spider gears really don't like one-wheel burnouts or shock-loading. I blew up an R200 with one wheel spinning on gravel and then hitting pavement. But, that was being stoopid

I'm pretty sure that the input shaft is different (longer) in the Z31 box. Not sure about the rest of the internals. Hope this helps - Doug

Do yourself a favor and don't waste the money on a Centerforce clutch. I have the heaviest 240mm DF in my turbo 240 and I'm not happy with it. It's OK under normal use, but even on street tires, sometimes it will slip when you have solid traction. I know that I'm not the only one who has experienced this. If I dump it at 4K, its alright on slicks, but if I try to walk it out on street tires, it won't hook up. I guess that it bites OK if you drop it, but if you slip it a bit, it won't hook up for a long time. That's the best way that I can explain it. Doug

I've got a fix for you - Jet (company that makes performance chips) has a temperature switch for fan control, turns on at 195 deg. I used to have my fan wired with a manual switch that turned on the relay, along with the Jet temperature sensor. Then - if I didn't turn the fan on, it would come on at 195 all by itself. Easy installation, 3/8 NPT with a one wire hookup. It is wired to ground the fan relay, turning it on. My last update to my SDS computer added fan relay control, so the computer does it now, but the sensor is still there, just in case. Sorry to hear about the amount of work it required to get it back together - I've done lots of stupid stuff to my Z, but I prefer to call them 'learning experiences' Good luck - Doug

Early 80's Toyota Celica and Supra rims will fit, They should be cheap and easy to find.

I had a bike from the same family - GPz 750 turbo. Same as all Kawa's of that vintage - Great engine - but the bike was heavy and clumsy. Narrow rear tire for the power -Frightening in the corners as the boost was somewhat unpredicable - very easy to have it come up and push the bike wide or spin the tire. I'm sure that the 1100 it will be a fun toy though. The EFI system was very good for that time. Doug

I run Z32 brakes on my 240Z - Is it possible? - Yes. Is it easy? - NO. If you can run a lathe and mill, it is reasonable in cost. If you have to pay someone, you would be better off selling the Z32 parts to a 240SX guy as they bolt on to that car and buying a well designed kit for your Z from Ross at Modern-motorsports or Dave at ArizonaZcar. As for ABS - with enought time and money, yes it can be done. Would it work correctly on a car that weighs 1100 lbs less - who knows? You would be in uncharted territory. Z31 hubs are a bolt-on for the early Z. Rear stub axles need to be re-drilled for 5 lug. Doug

You can configure the SDS to do anti-lag, but you really have to hate your turbo to do this to it. It does essentially the same thing, except it is pumping fuel through the injectors and retarding the timing under very high vaccuum (throttle closed), in order to have the fuel burn in the exhaust manifold instead of in the cylinders. Pretty hard on everything, I would imagine. But possible. Doug

Report on the 2.2 dodge pistons - They were made by TRW, forged flat-top in 87.5mm bore or 88mm oversize. Compression height is 1.610 inches or 40.8mm as far as we can tell. I don't have the engine calc. on this computer so I can't verify that number. They are not available from D/C mopar performance. Dis-continued like all the rest of the good stuff. I'm sure that some other company makes these pistons. Doug