Drax240z

I'm not sure you understant the severity of the heating that takes place. Remember that the head is allready cooled by the radiator, and I am assuming that a great intercooler is used. You still have 1400F+ exhaust gas heating the head, and are trying to pass sub 100F intake air through it. Even if you lower your intake temperature to 80F with an IC/shielding on the intake/etc you still have a huge temperature gradient in the intake port to contend with. What I am trying to say is that changing the intake charge temperature by 20 or 40 or 60F isn't going to solve the power loss issue created by a non cross-flow head. (though it will help) 600HP L6's... well you'll have to ask the people that are doing them. 240z Turbo, jeffp, Timz, etc. (I know you guys aren't 600hp, but you're certainly better able to describe the challanges associated with that type of build than I am) 8000rpm is a problem too I think. Crankshaft dynamics just won't allow that type of speed with the loads subjected by a high compression turbo setup. If you start to get resonance, or beating in the crank at that type of speed and loads it won't last long. I suppose it is possible to get a "super crank" made from somewhere to withstand this speed and power, but at that point I think you'd be better getting a "super head" made instead. Maybe the diesel crank is significantly stronger than the stock L6 crank, but I believe the dimentions and material are similar. What you are saying is feasible, an 800hp L6. But it would probably have a lifespan measured by a wristwatch. It certainly wouldn't be as reliable as the old supra engine putting out the same power numbers. Of course, this is just bench racing and really means not much in the grand scheme of things.

No way could an L6 get up there with the supra's. Not with any heads that exist in abundance in north america anyway. Sure, combustion chambers can be reshaped, pistons can be changed, ports can be ported, valves enlarged, etc. etc. But you still have the biggest flaw remaining: The L6 heads are not crossflow. This leaves you with big time heat going into your intake charge. I haven't done the tests myself on how much power this costs you, but I've read 11-18%. ie: a potential 700hp L6 becomes a 574hp L6, which we have seen from time to time. (a few on this board are in the area) I just reread and see that you are comparing with a untouched 4-valve motor... I'm not sure how well the stock supra head flowed, but I am sure it is comparible to a modified L6 head. However, the cross flow problem still persists!

Digikey is one of the best companies I've ever dealt with. Talk about the right way to run a business. Highly recommended.

Well to be honest, I was only involved with the body work of our car for a few hours, I was busy with the engine the rest of the time. As far as I remember, we used 3M spray adhesive to stick the foam together. Do a small test section first and make sure whatever you apply to the foam doesn't eat it! The next coat was some type of epoxy based paint or primer to seal the foam from melting when bondo/etc was applied. I believe the next step was to put down 1 layer of woven glass matting with an epoxy. Bondo was then applied to smooth any imperfections and ridges. (there weren't many, as we had our foam cut/shaped on a CNC router) From there, the plugs received a last coat of primer, then 6 layers of wax. Due to time constraints, we actually layed the parts up on these plugs, and pulled the body right from the plugs. Ideally you'd make a female mold from the plugs, and pull the body from that so that you had your best finished surface pointing out. We used 4 layers of woven (I can't recall what weight) e-glass with resin. We had an extremely flexible body (we made a 1'x1' sample, and could bend it back on itself without any cracking!) that weighed in total 14 lbs. Most teams that used carbon fiber/foam were around the 20lbs mark, so I'd say we were pretty sucessful. Anyway, I am far from an expert. I think the resident expert on this stuff would be Terry. (blueovalz) He's certainly played with this a lot more than I have. Final results of the body were rather good, even though the texture of the matting showed through a little. It added a neat effect actually, but its hard to see in pictures. [/img]

The Ethofoam (sp?) sold by home depot (the blue and pink stuff) works just fine for plugs, sands easily, etc. You do have to seal it before applying any bondo/polyester resin/etc however. Its fairly inexpensive and easy to work with in my experience. I'll add a picture... Raw foam, shaped and sanded prior to coating: Foam plug coated with epoxy, bondo'd, and primed prior to waxing/PVA: [/img]

I was in Detroit at the FSAE competition when Carroll Smith died... For those that don't know he's been the head judge of that competition for the past (12) years I believe. A great loss to that competition to be sure, as he had helped transform it from a little regional event to the worlds largest engineering competition, as well as the largest race week in the world. (by number of teams) If anyone is interested in more information on the pilot/teacher/race car driver/engineer that was Carroll Smith, check out the following thread written by one of his close personal friends, Dr. Bob Woods. (also of FSAE fame) http://fsae.com/6/ubb.x?a=tpc&s=763607348&f=825607348&m=9526016323

I think Scottie-GNZ is using a similar idea... (If I'm following you correctly)

I would think it depends a fair bit on the track in question as well. If we are talking tight, twisty parking lot autocross, I think the Z has a chance being smaller and lighter. I think as you stretch out the course however, the traction/power/high speed stability of the viper will come into play and take over. We know a modded Z can take a viper in a straight line. I'd say its possible for a "super Z" to be able to clean a stock vipers clock at least on a slow road course/parking lot autocross. Sticky tires can take you far!

I would think that a BOV will help performance, providing you are shifting that is. Simple physics... the faster the turbo spins, the more power you have. If you slow it down excessively every time you shift, the turbo isn't letting you produce as much power as it would if it wasn't slowing down as much. BOV is a simple mod, 1st generation eclipse BOV probably will cost about $50. Manual boost controller, another $20 for parts. You can probably run 9 or 10 psi on good quality gasoline without an IC. Then you have $400 ish to sort out whether you want to do exhaust or intercooler first. If your current exhaust is smaller than 2.5" diameter, do that first. Otherwise, I'd go for the IC.

Anyone found a good source for a replacement cable for the parking brakes? (talking 260z here) The front linkage is at maximum adjustment and the rear cable is still slack. (its old and stretched) Has anyone had sucess with just making a new cable from scratch?

I think you are going about this completely backwards. Having 2 used turbos that work doesn't mean you should build a car around them! In my experience, the only thing to design a car around are the tires! Anyway, figure out what your power goals are, and go from there. 2 stock GN turbo's are going to require some serious displacement to spin them up, and with that displacement you are going to probably end up with a stupidly fast car. In order to drive the car safely you'll likely have to spend $1000's on suspension, wheels, brakes, rear end, roll cage, etc. to the tune of easily $5000-$12000 depending on how extreme you go. So at that point, is it really worth it to design around some $500 parts? Sound like it is time to do some reasearch! I'd love to see a car that needed 2 GN turbos, but I think you need to know what you are getting into first!

Might be too late to chime in here now that metal is being cut, but free advice is free advice. 9 degrees sounds like too much to me. It is generally accepted that boundry layer seperation occurs at 10degrees or so. I would think that at 9 degrees, your car may be very sensitive aerodynamically to pitch changes. (ie: nose goes down as you lift, diffuser angle becomes more like 14 degrees, seperation occurs, back end gets light due to lack of load and downforce on rear wheels) Most diffusers aren't a flat plane, but instead a curve. Seperation tends not to happen as easily, not as drastically, and the car should be less sensative to pitch changes I believe. Anyway, just off the top of my head. Take it as you wish!

Well realistically you could have a perfectly fine engine there. But it isn't a matter of bolting on a turbo really. It would involve the turbo + exhaust manifold, making new exhaust piping, and new intake piping as a minimum. However, at that point you'd have a turbo but it would be doubtful that your stock NA fuel injection would be happy about it. You'd have to find a way to supply more fuel, which would probably involve a new fuel pump, new pressure regulator, new injectors, an extra injector, or something along those lines. Plus at this point you'd have a fairly restrictive intake system, as the NA cars weren't opened up for as much airflow as the turbo engines were. (ie: throttle bodies, AFM, etc) To really make decent power you'd have to swap all that stuff to the turbo parts. (which are probably STILL undersized really) So at that point, the only thing holding you back would be your camshaft probably, which isn't designed to be used with a turbo. You could swap in the turbo cam too I suppose. Of course then you might want to concern yourself with the higher compression ratio of the NA engine (which really isn't THAT high) and the weaker piston ring lands... It might be worth while to swap out the pistons too... Hey, and the head while you are at it! Of course, then the block is weaker in the NA car than the turbo car as well... I guess what I am trying to say is that you would be infinitely further ahead (both as far as time and money go) by finding a running turbo car with lots of rust, and swapping the whole engine over. You'll find 1000 people here that will testify that projects snowball uncontrollably, and even if you think you'd be happy with the minimum, chances are you'll want more very soon.

4-wire heated is metric as well.

I think the reason you don't see 3" DP's is because you can't get at the bolts when you flange it. Also, as you say the stock opening is 2-1/8" so what is the point? As for mild vs. stainless steels, I'd suggest bucking up and going with the stainless if you are going through the trouble of making it yourself. The thermal properties of most stainless steels (I'd stick to 3XX series) are much more suited to this task than any 10XX series mild steel I know of. Also you get some corrosion resistance as well. I suppose you could ceramic coat a mild steel DP and that would be a viable alternative. As for an O2 sensor bung, I believe all you need is a M18x1.25 (Or is it M18x1.0?) nut. Its huge and a bit unsightly, but it will work. Alternatively just buy the correct tap and make your own bung.

Hey Len, nice writup with some good info. Make sure you do an update when you are back at 7psi as well... Started running rich: You are cramming denser (cooler) air into your cylinders, however, with the loss of boost the net result is less air overall. In which case the same amount of fuel is too much. Go back up to 7psi and you'll be back on track. On the highway you will get much more of the cooling effect (wind chill on the IC) and have much denser air, which might be having more effect than the lost 1.5psi of boost. (though it doesn't seem to me that it should have that much effect) As for fuel economy... you turned your fuel pressure down man. You are making less power on less boost, of course your economy has gone up! Looking forwards to hearing more results!

Just a thought, are you sure the 300 mags are 4 bolt? All years except 84 were 5 bolt if I remember correctly. I'm sure you've checked, but it would suck to buy wheels you can't use.

Uhm, don't even think about it! No it won't run fine. I'd suggest following others advice here, get the car running. Do some research on turbos and turbo engines, and then decide whether you want to do the turbo swap or not. Knowledge is probably the most valuable tool you can have when doing a swap like this. (though we've proved time and time again that it isn't a necessity!!)

Personally I really like the minidisc players by sony. Mine lasts for 70 hours on 1 AA battery, never skips, and can fit up to about 100 songs on each mini disc. (which are about $2 each)

Heh, no wonder you didn't pick up the phone earlier today, too busy working on your car! Looks sweeet! Sorry Scottie, but I want to see James deep into the 10's!! (L6 power baby!)

Funny story. This took place in Calgary at a Flames game earlier this year. The guy hopped over the glass, slipped on the ice, and KO'd himself. They took him off on a stretcher.

Looking for a Wintec2 EPROM for a TEC-II asap. Please let me know if you an hook me up!

Lockjaw, if you are TIG'ing it is really easy to tell if you have pinholes or not. You have way more control, and more visability than MIG welding. As for welding tubing/pipe, it sucks pretty much. Your best bet is just finding a really comfortable position, and try to spin the piece you are welding as you go if it is convenient. I find the more I stop and start a bead with Mig, the more likely I am to have a hole.

Looked pretty legit to me... However I have to wonder if any turbo engine, even a 1.8L, would breathe through that tiny tailpipe. Maybe its just for show and he's dumping straight off the turbo in reality.

Good suggestions all... Once you get it sorted out with an EZ out in the bolt, I suggest putting the bolt through a few heat cycles witha propane torch, and cooling it rapidly with something like WD-40. I found that the expansion and contraction of the bolt with heat allowed the WD-40 to work its way down the thread. 2 or 3 heat cycles soaked down with WD and I removed a couple broken ones no problem. (with vice grips since I had something to grab onto) Worked for me anyway.