240Z Turbo

I don't have an RB26, but twinturbo L28 with NOS. I don't know if it was track prep, but the Nitto 275-50/15's did not hook for crap in Montegomery. I was spraying 100shot nitrous and 10psi out of the hole and spinning the tires every time. I could only muster a 1.9 60ft with 11.2@129.45. I suspect the nitrous played a roll in the problem. The nitrous hits so hard I think the tire cannot handle such a quick transition from still to moving. This was also with an auto trans, so it was not like I droped the clutch. I doubt this helps, but I think you will want to get some slicks!

Horns vs No horns. Think of a wing on an airplane and what exactly causes lift? Pressure differential. Same goes for adding airhorns. The gains are due to a pressure differential created and the velocity of the air is greatly increased as it enters the stack because of this. I used small stacks on my last intake manifold and have heard they work just as well in forced induction applications. This was during construction of my last intake manifold.

I think that is called water pump osmosis, the diffusion of waterpump fins through a cast iron block.

Stony, you can order bearings to almost any size you desire. For example, you can order a bearing with the same OD as the stock 240Z bearing, but with a larger ID for a bigger stub axle. My buddies shop has a catalog of bearings with many different sizes. As far as shortening the shafts, Greg Kring in Dallas has a shop that shortened his and resplined for about $100/per. You can send me an e-mail and I will give you his information. turbo240z@yahoo.com

Stony, you can order bearings to almost any size you desire. For example, you can order a bearing with the same OD as the stock 240Z bearing, but with a larger ID for a bigger stub axle. My buddies shop has a catalog of bearings with many different sizes. As far as shortening the shafts, Greg Kring in Dallas has a shop that shortened his and resplined for about $100/per. You can send me an e-mail and I will give you his information. turbo240z@yahoo.com

very interesting, but that did not look like it was fun to make! What is up with the #2 runner? It looks as if it is not connected. Also, provision for an external wastegate?

Tony, that 1.15 a/r will NEVER spool with that setup. A .58 will provide excellent spoolup and will flow enough to support 500+RWHP. I ran a .81 a/r on my T64 and it was lazy as hell, but I was using a large converter so that brought it on much quicker. I also ran my 60-1(p-trim .58 a/r) and it gave full boost by 3700rpm or so. I would probably run a .69 as it is a compromise and you are not running that big of a compressor wheel.

Front header is finished and I should have the rear header done a week or two after TG.

I ordered all my stuff from Specialty Products Design . The flex sections can be ordered from Turbonetics for about $50 a piece and they are 304SS. You can also order the mucho expensive ones from Specialty Products Design listed above. As far as the tranny, I will be swapping to a 2004R when the new header and intake are complete. Only 1 project at a time says my wife! The Starion/Conquest tranny will support 320hp@wheels all day long with no slippage issues. I would say that is your best bet and it gives you a massive .68 OD ratio. Cruise at 90mph and 2700rpm!!!!

Well, I hope it will make over 525hp@wheels at 23psi and 100shot nitrous. Scottie and I had a good conversation last night. Sorry Scottie, I must tell. Scottie dynoed his car to the tune of 479hp@wheels. We compared his best 1/4 past from the 1/8th to 1/4 to my best pass. Here were the results: He ran the 2nd 1/8th mile .003sec faster than me I gained .4mph more over the second 1/8th mile So, assumming the cars weigh the same we are about dead even in RWHP and that was 16psi and 100shot nitrous. However, I cannot compete at this time with Scottie's ability to run the 1st 1/8th mile, which is where the race is run. Anyway, the front turbo is complete as I ran the last tube today. I have a few more welds before the front is done. I will hopefully have the money for the rear turbo within 2weeks. After that another custom intake with carbon fiber plenum and I am ready to kick some GNZ ass!

Don't mind the old twinturbo exhaust setup still in the car. I need to remove it before I begin routing the rear turbo.

Still running the 16Gs and it will all package without cutting the hood or other parts of the car. However, if I have to I will. The front turbine housing sits just inside the DS strut tower with the compressor housing sitting infront of the DS strut tower. The hood is about 1/2" from the compressor housing. I will take a pic on the car and post it.

POS, yea its a joke as someone called my old header a POS. The tubes are large, 1.75", and tube length is in the 23" range per primary. Thermal expansion, what does that mean? HEHE! Not to worry, it will be ok. Flange is 5/8" cold rolled steel that I machined entirely on the mill. Holes have been oversized to accomodate some thermal expansion. BTW, did you notice the turbo's are going to sit up by the hood?

I don't know, how much can I charge myself?I know the primaries are a bit large, but it is the same size I ran on my last header layout design. I would think 1-5/8" would suffice, but it just makes things easier as my exhaust ports are about the same size as the 1.75" primaries. Sunbelt made the exhaust ports "D" shaped. Yes, the setup didn't spool for $hit before, but the NOS spooled the turbo's instantaneously at the track. Should be interesting!

This is of the 321SS variety.

Just about the same results as TimZ on his system, but as we discussed and I mentioned in an earlier post, the backpressure in that part of the manifold may be much lower than if measured up in cylinders 1-4. Tap a hole by the #1 port and measure there if you have the ability before you take the thing apart. I would be curious.

South Florida Performance is making the manifold and will have TimZ's old manifold by early next week to begin the initial prototype design. Will keep everyone posted.

Dimensions....Just click!

When I lived in Houston I had Westside Performance rebuild my Nissan L28 motor. They have alot of experience with this motor and also have a torque plate made by a friend of mine. Jeff is very professional and reasonable. This company builds the short blocks for Hennessey(sp?) Viper.

The larger 50mm wastegate is the way to go as it will help to further reduce the backpressure. I can get you a good deal on a HKS 60mmGT wastegate and I would bet it is comperable to the price of your 50mm Tial. TimZ just sent his exhaust manifold to South Florida Performance for them to start making custom manifolds for the Nissan L6. They will be mild steel and carry a 3yr warranty against cracking and will be in the $800-$900 range, maybe less. As far as your backpressure, even if you measure the backpressure at the turbo it is probably not a reliable assessment of the true backpressure in the system. Remember, in that area you will have the least backpressure. I would bet that if you measured the backpressure at the #3 cylinder it would be much higher. This is my theory as to why you do not see hp peaks above 6K rpm on most Nissan L6 turbo apps that use the stock cast manifold. The stock manifold just will not flow big #'s as it is a restrictive design on high hp applications. I never peaked hp on the dyno even at 7200rpm, but I also used a POS turbo header. I will redyno the new long-tube header when it is complete.

Here is a source BATINC

In some instances even the -4 can supply too much oil. I would suggest using a -3 line to your turbo which is what I have been using for quite some time. You can go as low as about .095" restrictor to the turbo. If your turbo burns oil with the larger -4 line then step the line down to a -3 and it may solve your problems. -6 should not be an option. Basically, the seals in the turbo are dynamic and over oiling just forces the oil past the seals.

I run 1600F all day long before the turbo on the Greddy EGT. I suppose there will be some discrepancy between EGT manufacturers. That is a peak temp that occurs at the top of 3rd gear. I would say 1575-1600 for short bursts, drag racing, is fine. BTW, don't be confused, just because the exhaust temps are that high does not mean the pistons are seeing those temps. Remember, the cylinder walls carry away heat via coolant and the pistons are also cooled by the incoming charge.

Folks, this is a prime example of how/why you don't try to use a normal O2 on turbo apps running alot of boost and making good power. The O2 readings are useless in most situations. Hell, I tuned my car to .95V(0-1V) and on the dyno I was at 14.1:1. EGT is the next best thing and wideband is where its at. My last dyno session was 10.9:1 tuning by EGT and I picked up 40rwhp by tuning to 11.6:1-11.8:1. The moral of the story is do not trust a normal O2 for full boost tuning.

there is a point where the efficiency gained from raising the compression is outweighed by the power generated from the ability to run more boost. Make sense? Here is a hypothetical example: 7.4:1 I can run 24psi on 94octane 8.5:1 I can run 19psi on 94octane Although I gained 5% efficiency from the rise in compression, the 7.4:1 motor made more power because I can run 5psi more boost w/out detonation. So, try to keep the motor in the 8:1 range for most street applications.