Lockjaw

I don't have it either with the Bosch asjustable one I got from JWT. Of course I got to plumb it over by the return line, so that is in its favor.

I have not heard of anyone sending an intake off to extrude hone, so I can't say good or bad. I would think it would be pricey for the HP gain, but that is just my opinion. The 240SX tb is a good cheap mod. You should be able to get a machine shop to fab up a 1 inch spacer out of aluminum if you give him a gasket or the TB to use for a template. I think I paid 25 bucks or something like that.

Well if you have 4.5 years on the engine, that could explain your blowby issue too. I mean yes you have good compression and leak down is good also, but you could have a little wear in there. If it was me, I would plumb the top of the cover back infront of the turbo and drive it. My turbo engine uses oil, always has, but it has forged pistons and I flog the mess out of it at the track. I have about the same amount of time on mine, and plan on freshening it in a couple of years. I guess I could go with JE's next time and get a tighter cylinder wall clearance. I don't know what else to check. Good luck from here.

Yeah but you guys are forgetting one thing, the intake sits over a very hot turbo. I would bet a sustained run would see the bottom of that glass manifold start to char. You also would have to consider the proximity of the manifolds mating surfaces to the head as well. Very tight confines there. I am sure you could insulate it to a good degree, but if the heat every did manage to melt/burn thru, you would not have an easy time getting the car home if you were out and about. Just someone's .02

Are you getting black smoke out of the tail pipe when it happens? It is my only other hunch. If so, you could have some sort of vacuum leak between the turbo and the intake manifold causing it to lose pressure under boost. It would eventually catch up. I had this problem with an old rotomaster turbo, and it had a gasket between the backing plate and the compressor housing that was all but gone. The car would run, and when it boosted, it went way rich, but if you kept your foot in it, it would eventually clear out and go. I would check the hose that connects the turbo to the J pipe under the intake manifold and see if it has a crack or hole in it. Are there any other symptoms? Any problems with the car starting, idling etc? Oil should be pretty dark in a turbo engine. Imagine what it has to go thru to cool the turbo. It gets hotter than any part of the engine.

The best DSM engine is the 6 bolt one, so if I were going to go thru the trouble of installing one, I would make sure I got the best one. I believe 6 bolt refers to the number of bolts holding the flywheel to the crank, but you should double check me on that before proceeding. I am sure one of the good DSM sites could enlighten you on the subject.

Well I would say and o-ringed block pretty much would rule out a blown headgasket, unless there is major head warpage. What kind of rings did you run? The oil control rings I used in my engine had a fairly wide gap on the little flat rings that go above and below the wavy part. I recall being concerned about it, but I have never seen anything where someone has given a spec on ring end gap for those little thin deals. Also what kind of headwork did you have done? I have never replaced valve guides, but I usually always replace valve stem seals. I don't know how oil could get into the valve guide area except past the valve stem seals. Even if you had new ones installed, a small burr on one valve could make a hole where oil could get by. I got Beck Arnley seals from Advance Auto Parts online, and they are shorter than the one's I took off the P79 head I set up last week. Don't know if they are any good yet, but when I ring the engine and get it back together I will report in on them. They were nice and soft though, unlike the one's I took off. If you are not smoking and using oil, you could always just run a line from the valve cover into the hose in front of the turbo and make it go away. Know what is funny, the engine in my 260 has a major smoking problem, yet I have no blow by out of the valve cover. I have it out of the tube on the side of the block though. Of course that is plumbed in. I also know my compression is low on the back two cylinders. Go figure that one out. Good luck figuring it out.

You have mail. This evening will be fine with me. I would just like to see them out here to see what people say. Just remember guys, I am merely the messenger.

If you could see the picture of the intake, you would know why I asked that question.

I have some info on a Z car that is a claimed 9 second car. Here is the quote from them. The car run 9.63 @147mph. It is street driven and runs the stock computer set up. We have 4 additional injectors for additional fuel. The car dynoed to the wheels 738 HP at 24 lbs of boost. We are planning on putting on NOS to help keep up with the outlaw class. With some suspension tweaking and wider slicks we are sure the car can run low 9s. Thanks for writing. And we have never had a problem splitting the intake manifold. Hopefully Turbo magazine will picture the car in the magazine in the up coming future. __________________________________________________ I have some pictures I could email someone if they can put them out there. I don't have a wedsite to put them on. Email me and I will send them to you. These show the hogged out intake manifold, head, pictures of the engine compartment, etc.

I have never seen a claim on it either. Certainly they should be able to tell you something if you called them.

That is the stock intercooler, and it sucks. Turbo cars run much better once the ambient temp drops below 70 degree's. When it is really cold, the improvements can be very dramatic. The air cleaner that is where the turbo is drawing air should be in front of the radiator, Corky Bell emphasizes that in his book. It is also quieter. An air to air intercooler that is sized properly can get the intake charge down fairly close to ambient, say perhaps within 15 to 20 degree's. An Air to water can do better than that for short periods IF you introduce ice to the resevior. When it is really hot, nothing runs well. It is not unusual for a high performance carb'd engine to require rejetting in the summer and winter. Fuel injection make life so much nicer.

Good luck with the qwest to get your numbers. I have faith. Besides, you are charting new territory so I won't have to break in Clark on it.

I believe I ran 140 mains on my 40's with 33 mm chokes, and about a 190 or 195 AC. I found my car ran much better with the F11 emulsion tube, the F16 was to fat to suit me. I wonder if you are getting any black smoke from the tail pipe when it bogs. Usually a bog means you are lean, but also when lean, you should hear the carb spit too. If you have another set of pump jets, I would try bumping up to the next size. I would think that you should not have to make a radical change to move up in altitude, maybe increasing the size of the AC, or dropping the main jet one size. One thing that will really help you nail down your problems is and air/fuel mixture guage, or whatever they call them. Plumb in an O2 sensor, hook up the gauge and go for a drive. It should be able to tell you immediately where and what your issue is, and then you can take steps to address it. If weber parts are still as expensive as when I had them, the gauge is money well spent.

Was their anything that happened that you can recall that could have caused a problem? ie, over heat, bad gas and detonation. I have all my vents plumbed back into the intake tract since I don't like the smell, and it is supposed to make the engine internals stay cleaner longer. What does the underside of you oil cap look like? What about your oil? Do you see any oil in the antifreeze? White smoke from the exhaust? I would only use the Nissan gasket or the HKS one on a turbo engine. I am currently using the nissan gasket, and it has done a great job for me. If you change the head gasket, be sure to have the head checked for warpage. Sounds like Jeff has nailed you problem. Good luck with the repair.

According to the formula, the 62 flows 70 pounds, so it should provide about 1000 cfm, which is enough for Jeff's target. The other distinction is I believe Jeff is after 600 flywheel hp, and he is not that far from it with his current set-up. The extra 20 pounds of air provided by the 62 should be sufficient, IMO. While I am not trying to fan the flames and create another Jerry Springer Episode, speculation was his EFI set-up and turbo could not support JWT's claim of 450 flywheel hp, yet he dyno'd 415 rear wheel hp. It may take some tweeking, but I am betting he gets the number he is looking for with the 62. Just one guy's opinion. Go for it Jeff, and lets see some big numbers.

Yes it is possible to do that, and the E88 has a smaller combustion chamber than the P90, so that will give you a compression bump. But the turbo comression is 7.5 roughly, so don't expect it to have 10 to 1. Do you have the E88 head that looks like the E31 as far as the combustion chamber design, or is the standard open combustion chamber?

If the turbo is burnt up as you say, you should see oil smoke coming from the exhaust, or hear some racket when it spools. You can checj the condition of it generally by looking in the compressor housing for oil. You can also grasp the shaft in the compressor housing and gently see if there is any front to back and side to side play in it. I would also check you waste gate actuator is working properly. Alot of the time, where the rod connects to the actuator, rust develops, and that could bind it up some. You could also have a problem referred to as mystery turbo death, which is a term some friends made up to describe a common ailment we found with the turbo cars. Essentially, you should disconnect the wiring harness from the ecu, spray the connections and pins down with brake clean and reconnect. Do the same thing with the airflow meter. Alot of the time, that fixes mysterious random car issues.

Well the only one I know about is the Camden one that Jim Cook Racing sells, and it uses a Holly Projection to fuel it. It is a roots type blower and comes with all the stuff to make it go. The one benefit I see to it is that you could at least run a header. I am sure it is a torquey unit, and it seems to me if you started out with a turbo engine you could run more boost. There is lots of discussion on the merits of supercharging vs turbocharging. I like turbo's but I haven't ridden in a SC car, so I can't say much about it.

Corlky Bell has one, and it is set-up for a T4. I wonder if Rev Hard would do one. I was thinking of having 6 runnerscome into a centrally located flange and have the flange face down instead of out. Like they do on the 240sx manifold.

Do you mean the camden one like JCR sells, or some one off centrifugal?

I wonder if we knew a good welder if we cut the manifold into 3 pieces and port it, and then weld it back together. Hummmmm.....

Sounds like she is ok to me. I think there is no doubt you can spend some outrageous money on a Z engine. The guy who did my machine work told me I needed to get carillo rods if I wanted to run over about 5 or 6 psi. I was like they run more than that from the factory. No wonder his shop is no longer in business. I guess the scat crank would probably eliminate the crank resonance issue's with the factory crank, right? I have always wanted to try the 240 crank in a 280 block and bore it out to 89mm and see what that runs like. I don't know why, just do. I bet it would turn up some rpms though.

Yeah, Corky's book breaks stuff down, and I did my calculations based upon his book, and then got happy when my turbonetics catalog in and it was not in CFM. So I had to recalculate it. I was a little miffed. I know how you can get 600HP real easy, NOS. HAHA I have one word of caution about the head studs. There is a guy here in town who had what probably amounts to the fastest Z car with an L6 in it in Alabama , and he or his engine builder cracked his block installing the studs. I guess they bottomed out or something. Anyway, he had the worst time keeping head gaskets sealed up until he found out about the crack. I don't know if he has ever put it back together though. He had a big topend turbo cam that he said wouldn't idle below 1200 rpms, ported head, big valves, a tech II and it was a 3 liter too. HE kept breaking tranny's so he ended up getting some sort of adapter plate and running a turbo 350. If I recall correctly, he was running low 7's thru the 1/8th on the 5 speed. I don't know that he ever took it to a quartermile track. If I recall correctly, I think there is a company in Japan that makes a bellhousing to adapt the 300ZXTT tranny to the L series engine. I think Clark told me about that. I am thinking of a turbo 700 or 4L60 or something like that, with a nice converter. Or the Starion auto. Turbo 700 would probably be cheaper, and I have a pal that knows how to put one together that will stay together. I think you should stud the bottom end too. Probably pitch the crank and all 7 main caps thru the oil pan. (There is 7 right?)Might be cool to watch, but not cool to fix. May be time for some strut tower braces and a roll cage, if you don't have them already.

The 62 flows 70 lbs per minute, the 60 trim he currently has flows 50. I would have to hunt to convert to cfm, but I believe the 62 flows 10 percent more than a 60-1 and the 60 flows about 900 cfm. The problem with cfm is turbonetics lists all its compressor maps in pounds.