Scottie-GNZ

How is a turbo 5.7L V-8 vs a turbo 2.8L L6 apples-to-apples?

This is kind of the point I was leading up to. More speeds and stiffing gearing is the wrong way to go for a turbo car. You are not tying to rev quickly to get to and stay in a narrow power band. A lot of the small displacement turbo drag cars are starting to catch on. Dave Buschur recently broke into the 7s @ 170+ with his 2.0L stock-block DSM. Tranny of choice? A 2-spd Powerglide. 2.0L, for chrissakes!! Damn, thats scary.

Just curious. Why do you think your L28ET needs a 6-spd?

John, they are a little skinny but others have done fine with 235/60 BFGs. They should do fine if you learn the break point and stay within it. I used 275s and this is what worked for me. 16-17psi, back up to the edge of waterbox to get them damp, spin the tires lightly to move froward out of the wet area and get the entire tire wet, lightly on the gas to get them spinning, then romp on the gas to spin them hard counting 1-2-3, then drive out of it. Watch the RPMs when burning out hard. Keep it in D with an auto or start in 2nd with a stick and maybe even have to shift. My trans upshifts to 3rd and my speedo registers up to 90mph in that 1-2-3 count and it is easy to over-rev. You probably already know this but a lot of folks tend not to focus on that. BTW, I do this with a line-loc, a must-have. If you do not have one, then after moving away from the waterbox, brake rev it and drive hard out of it. Nittos seem to like a little more heat than BFGs. The rest might not apply since my engine setup is different and I use a trans-brake, another must-have if run an auto. I bring it up to about 5-6psi boost and floor it and release the t-brake at the same time. Anymore boost and I waste the tires. That is my break point.

You want to have a jet-hot/ceramic coating or wrap for the exhaust manifold, but I think a thermal dispersant is what you want for the intake.

Moisture gets trapped under the wrap that will eventually affect regular steel. Lots of headers have gone to the scrap as a result of folks unknowing.

I spoke to a BFG rep at Gainesville Raceway 14 months ago and he said the "Big-Boy" sizes would be available soon

I agree with Dan on the Toyos. They would have been my choice if my car was not so oriented towards drag racing. The heavy GNs commonly get 7,000 miles on the Nittos. Clint, I am not sure on the mileage of the Toyos, but Eddie Bello drove his RA1-shod 911 Turbo from NYC to West Palm Beach, ran 9s @ 150+ and drove home (2600 mile roundtrip) . The same tire will pull massive Gs on the road course. You can get 205/55-14 and 225/50-14 RA1s but they are extremely short. Anyone caught in the rain with BFG DRs is at great risk!.

Scotty, I assume you are wanting to wrap the exhaust manifold. Header wrap works great and I can actually hold my DP with the car idling. HOWEVER, I would not recommend putting header wrap on anything but stainless steel.

Unless he has a cam that moves the peak power way up, those numbers do not compute. I would expect to see a lot more torque than that. Now, if it was 320 at the flywhel, that would make more sense.

The problem you are facing with the stock turbo is one that just absolutely killed my ET when I ran the stock turbo also. I was running 245/50-15 ZR tires and struggled to get any traction at all. I upgraded to a t3/t04 and immediately cut a 1.74 on the same tires. Funny thing is that you hear so many complaints about turbo lag and I thought that instant response was just as much a problem . If I had to do another L28ET in a 240Z, I would probably use a lesson learned from my current setup and run a 3.54 or even 3.36 with the widest ratio gearbox available for drag racing a turbo.

DRs do not need VHT to stick. They have a traction limit and the trick is finding that limit and living within it. When you do, the results are amazing. You certainly cannot just rev it up and dump the clutch. For me, anything over 7+psi boost on the transbrake blows them away, but 5-6psi nets low-1.60s and the occasional 1.50s. You need to check out the NHRA Import Street-tire class and see guys launching 800+hp Supras with DRs and running mid-9s. Launching hard with DRs takes patience to find the "sweet-spot" and discipline to stay in it once you find it.

Jim, I am sure you are correct. I am on vacation and checked in with a modem (I forgot how bad it is). It seemed to go out to lunch, so I stoppped it and plugged in www and it responded almost immediately, relatively speaking .

Jim, fix that link in the sig.

Look up ZR8ED and send him an email. He did the swap and is quite happy with it.

The overheating problem is a concern. However, if someone like me running a 28" wide Bell I/C, big tranny and oil coolers have no cooling problems at all, then anyone with similar equipment SHOULD also not have a problem. Of course, there are other variables like timing, etc, but I believe the key is having adequate airflow from the fan and releasing the underhood hot air. I have a Griffin rad, about 15/85 coolant mix with RMI-25, WaterWetter, 160* thermo. I think the key is a shrouded fan that moves lots of air and 280Z hood vents recently replaced by a cowl hood. Even under extreme racing at the track in 90+* temps, I rarely ever see 180*+ water temp.

Regarding Waterwetter, etc, see my post on overheating in "How Efficient Is The COnquest Intercooler?".

I am not a big fan of OEM CAR I/Cs and my logic is simple. Any L28ET looking to install an I/C is probably looking to turn up the boost and increase HP. Many OEM car I/Cs, like the StarQuest, were designed for engines smaller and with less HP than a stock L28ET. How can it be expected that these I/Cs would efficiently, repeat, efficiently support a warmed-over L28ET? Only way possible is if the OEM designed in quite a bit more capacity than the targeted factory HP rating. Lets say the target HP for the L28ET is 275hp, achievable with the stock turbo. In order for the StarQuest I/C to efficiently support this, it would have to been designed with about 70% additional capacity. I dont think so. That is not to say you cannot still use it and get decent performance, but how efficient is it? Remember the objective of an I/C is to reduce the intake charge allowing you to increase boost w/o increasing heat and w/o significant pressure drop. Since you are measuring boost at the intake, it is difficult to know the actual boost at the turbo. As pressure drop increases, the turbo has to work harder to get the desired boost at the intake. The harder the turbo has to work, the hotter the charge it is delivering and the less efficient the I/C, the hotter the charge at the intake. An example of this is when I hit the limit on the Big NPR. I ran into a brick wall at about 400rwhp. The car was performing "OK" but had some strange problems, like not being able to run more than 20psi and more detonation than I liked. turns out at 20psi at the intake, the turbo was pushing 30psi and 325* charge!! At some point you get diminishing returns and start entering a danger zone, too much heat. I prefer to see folks target the large truck desiel I/Cs and OEM car I/Cs designed for higher HP applications like the Porsche 944, SupraTT, GN, etc. ANy one of those can support 300hp efficiently. Bottom line. If you are looking to crank up the boost for serious turbo performance, the I/C is the one thing not to skim on. As tempting as a $75 StarQuest might look, if you have to upgrade later, chances are the plumbing is wasted and you end up spending more in the end.

Checking in from the Big Apple. Cannot stay away for more than a day So, what is it? I obviously do not need it but if others did, I would get it and part it out. The owner cannot remember what it came out of but I can get it fairly "cheap". Will say one thing, it is from a fairly new car because it is clean as a whistle. It is an LSD and my guess is 3.90:1. He wants to get rid of the entire unit and unless I can move the diff, no point in me picking it and getting stuck with it. I will be back 6/19 so if we can clearly identify it and someone wants the LSD, I will get it and part it out.

I do not know what it is out of, so someone tell me. Nissan IRS 1 Nissan IRS 2 Nissan IRS 3 He also has a Jag IRS and wants $450 for it. Yes, it is upside down in case you were wondering. Jag IRS By my rough estimation, the Nissan diff is a 3.90 LSD and the Jag is a 3.0

I built one back in the late 70s with the same flare kit and a genuine 302 SBC (boy wish I had that car now). I used the Kennedy Engineering kit. 1st gear is pretty useless because of the gearing and the shift pattern with 1st being where 2nd is in a normal H pattern. Makes for destruction when trying to do a quick 1-2 and the clutch needs care. I never drag raced mine (meaning I never dumped the clutch) and only used 2nd-5th with about 62mph in 2nd. 13s is not considered quick for a hybridZ unless you go with a 305 or garden-variety 350. If he has any power, however, be careful on the top-end .

SleeperZ, thanks for clarifying things. I wonder how many people criticizing a part is doing so based on their experience with those parts or just theorizing.

Opie, welcome back. Been a while.

Good point. Not only is it single-turbo with a crossover from the pass side exh manifold, it appears to be non-I/Ced with the compressor outlet going directly into the intake.

What are you doing on a GN site?