240Z Turbo

OK, so I broke my promise! quote Oh yea, you made 330hp @ crank. CHUCKLE! I remember when my 1st turbo setup wasn't making much power either. Of course, that was about 3.5 years ago. Send me an e-mail and I will give you some advice on how to make more power. BTW, my 2.5hrs of street tuning netted a 12.2@121 on my old..old..old setup. Hey TimZ, did you not get over 375hp@wheels by street tuning alone? You Chevie guys are always so funny!

Now we are talking apples and oranges. I don't doubt that a shop doing corvettes can't just take a chip and mod it from experience for other corvettes. It is what JWT does all the time for people who buy their computer and never come to the shop. It is also what the GN guys do who order chips. I agree, for 1 particular car and type of setup you can grab an old program and may only require minor changes. However, this is completely different from me bringing my TT L setup to him where he has no database of programs and due to head design and other engine differences he can't just easily create a file. In this case there is no way to make 3-4 runs to determine any type of optimal program. I know TimZ is holding back from also commenting on this, but I think those of use who have alot of experience know the truth about what it takes. Even when I change my own setup it require substatial changes to the program. OK, I promise not to post again on this thread!

Oh, so in 3-4 passes they can somehow optimize the timing, optimize the AFR for all 64 points in the VE table, set all the acceleration enrichments correctly, set all decel enrichements, optimize TOG and IOT and correctly setup all breakpoints for driveability. I apologize, what was I thinking to doubt such abilities. Can the guy tuning also pull a rabbit out of his butt? Anyone can setup a conservative timing curve and dump too much fuel and have the car run. I was talking about properly tuning. Anyway, no big deal I guess I am wrong. Later!

The fact that GM paid to use the coil pack stuff has nothing to do with the ability to tune a motor in 3 or 4 dyno passes. There is no way in hell you can correctly tune in such few passes. I have been using the system for 4 years and have some experience dyno tuning the Electromotive and Haltech. Even if you could optimize your parameters with some design of experiment it would still take alot of dyno pulls to determine the optimal timing, fuel and cam timing under WOT that achieved the best results. This is only 1 small area in the whole tuning process. I personally find it best to dial it in on the street and only use the dyno to determine optimal cam timing and then to see what types of AFR I am getting under full boost. Nobody is trying to knock you or your buddy, but it is just not realistic to think that 3-4 pulls will accomplish much. Hell, it usually takes that many pulls before I can get the tech to even read properly on the dyno!

Norm, why do you want a 2mm gasket? I have one that I used for several months that is in great condition. You can reuse these gasket several times. Just let me know. BTW, they are about $175 from NISMO who bought the last of them from HKS.

I have run a 65 shot ontop of 18psi of boost with no problems. The result is very drastic as far as performance. For a small shot like a 65hp I do not think you will need to jack with the timing, but try to limit boost to about 15psi on pump gas. As with additional boost make sure you do not have any knock and it is good to use your EGT to tell whether you are running lean. I would keep the EGT's in the 1550F-1600F with the NOS and pump gas. I will probably spray on my new TT setup if I am confident it is all dialed in. If you have it kick off at a lower boost level the results are not as noticable in my opinion. The real fun occurs at full boost with the NOS. The funny thing is a small shot can potentially reduce knock because of drastically decreased intake temps, just have to watch for too much cylinder pressure. Oh well, enough rambling!

Scottie, I had a similar problem with fuel pressure hitting peak and then dropping off. It turned out to be my fuel filter and you can easily check this. Bypass the filter and see if the problem persists. Also, make sure your pump is seeing a constant 13+V under boost and somehow now dropping off. I would check the filter 1st before getting a new pump. The Pierburg I bought from Bell was about $200 and is rated at 680hp @ 70psi.

To give a comparison, the 16G compressor wheel is the exact wheel that came stock in the 280zxt T3. The tip height is slightly different, but the wheel is the same. So, your TDO4 is smaller and the 16G is rated at 505cfm@15psi, but that is also a function of the TDO5 compressor housing.

This is something that I am definitely going to do when I graduate. I am here in New Zealand and had the chance to look over an RB26 on an engine stand for quite some time along with the tranny. As Stony said the front diff is not in the ideal position, but I think that is somewhat trivial. If you are going to attempt this swap you had better accept that you are going to be doing alot of custom stuff and changing things at every corner. i don't see it as being impossible to relocate the diff with respect to the engine so that you can position the motor where it needs to be. I have always known the stock cross member would have to be scrapped and if you had the whole front clip you could graft it into the Z. the engine and front suspension has its own subframe that could be bolted to the 240 if properly planned. Anyway, to answer Stony's question. Mount the engine and then mod the pan to move the diff location. You will have to notch the tunnel on the passenger side for the transfer case and do all the other mods. It is a big job, but I think it can be done and you had better have that attitude if you were to attempt the swap.

McGuiver could do it with 2 sticks of gum, baking powder, 7 Q-tips and some urine from a bullfrog.

Ahh, Walker's old ride. I thought that thing had a 60-1, not particularly a laggy turbo. I have run the NOS ontop the turbo on a 60-1 and 18psi of boost. Just add race gas and you should be ok without doing anything else for a 65shot or so. Believe me, it makes a world of difference. I went 8.0@97 on street tires without a LSD unit with a crappy 2.16 60'.

Scottie MIZ, are you running an aftermarker fuel management unit?

A typical size for most apps would be 2.25" turbo-intercooler and then 2.5" intercooler to TB. You always want the intercooler to TB as big as if not bigger than the turbo-intercooler piping. My current piping will be 2.5" turbo's-intercooler and 3" from intercooler to TB. The intercooler is also a reservoir which is why you want to the same size if not bigger from intercooer-TB. There is no reason to run a 2.25" pipe to the opening of a TB that is 2.5". You might as well have run 2.5".

You are on track with TimZ and myself. We are colaborating on a control system for the tech and have been floating the idea around for several months. However, our main goal is the integration of wideband technology for use with the Tech. Now, if Tim would just get off his....Whoops! Sorry Tim! HEHE!

That was not my original thinking, but if you properly port the area around the wastegate hole and possible enlarge it some with a bigger puck, you could probably support 350@wheels with an internal wastegate. It would not be my setup of choice. I used to run A T04E with a 57trim @19psi of boost and had to do some porting around the wastegate hole to eliminate some boost creep. I had no problems after that. I figure that motor was in the 340hp@wheels range.

It is not the boost you need to worry about, but the flow. You can run 17psi with the stock internal wastegate and have no problems with creep. It is more a question of HP developed that will dictate the use of an external wastegate. 350hp is no problem for a factory internal wastegate and if you did see some creep you can just do some mild porting around the wastegate hole and it will solve your problems.

I believe that diff is actually an R190 unit. I forgot what input shafts are required, but the diff can be run in the Z.

BTW, you will see in my timing curve that I drastically take out timing when I hit boost. There are 2 modes of thinking when tuning. Less timing and less fuel or more timing and more fuel. I was speaking with TIMZ and he runs alot more timing than me at low boost, but he also runs more fuel, probably in the 12.5:1 range where I am in the 14:1 range. I will probably opt to add more timing in this area when my motor is finished and add enough fuel so it does not ping trying to keep it in the 13:1 range.

I made this JPG file of my timing curve for Ron and thought I would share it. It is roughly dialed in and I am sure it could be further tweaked. I am not recommending this much advance under boost unless you have a decent intercooler and upgraded turbo that is more efficient at higher boost levels. It is moreso intended to give an idea of how to formulate a curve for a turbo setup. All motors will be different, but this is generally a good curve although slightly more aggressive under boost.

1 light short of full rich should be about .89V 02. That should be sufficient and somewhat conservative. You should atleast be about 2 lights short of full rich on the gauge. The gauge only reads the O2 voltages and is solely a function of your O2 sensor. You cannot compare it to what someone else sees unless you have the same O2 sensor.

Huh? Why do you care if it is hand tightened. Because it is a stud, you gain additional clamping force with the finer thread pitch on the torqueing side. These studs go further into the block than the stock head bolts which alone gives you more ability to gain clamping force.

Preloading on the block side to cancel forces does not make sense to me. If you torque the studs in the block, bottoming it out, you exert force on the top side of the stud threads and the bottom side of the block threads. This is the same thing that happens when you torque the nut on the stud. So you have effectively now placed additional stress on the threads. Remember, the amount of threads needed is 1.5xstud diameter or 1.5x10mm=15mm. That means the stud only needs to go into the block 15mm before there are enough threads to adequately hold it. So why the need to preload the studs, just put them into the block as far as they will go hand tight and you have enough threads to hold it. Maybe I am off my rocker and could be wrong in my thinking.

Thanks to TimZ for scanning this and sending it to me.

The reason I ask about the RB30 crank in the RB26 is because JUN offers a 3.0L kit for the RB26 they say is for 1000-1400hp applicataions.

Here is a pic of the pressure port before the turbo. The bottom tube is the pressure port and the top thingy is the EGT probe.