SleeperZ

What's your RPM as you hit the traps? With my T5/3.90, I was well past the powerband when I hit the traps. Since I put in the 3.54, with no boost increase, I am hitting 109-110 traps instead of 107-108 traps with the 3.90.

More info please. How was it running before the rebuild? What sort of smoke? Have you checked (double-checked?) your cam timing and ignition timing? Verified you have no new vacuum leaks? Those are the obvious things when diagnosing...

So much for running a stock hood huh?

I hear you. I wasn't too worried during the pulls, as I had a few gallons of 100 octane in the tank. My base FP is running about 42-43 psi, and I think I'll increase it to about 45.

The device on the bottom of the stock TB is the BCDD, intoduces lots of air on deceleration, again not used with the turbo setup. Not sure which vacuum line you are referrring to, the small one on the bottom may go to the distributor advance or it may go the the charcoal fuel vapor cannister (I use the tb vacuum to run my cannister). The big one on the top is most likely the outlet of the air regulator, which helps maintain idle speed when the engine is cold.

Bernard: The turbo is just a stock unit with a TO4 fan and housing bolted on. I paid way too much for it, back when I didn't know what I wanted. It was advertised by Jim Cook Racing (same outfit that "sells" the Camden supercharger for Zs) as a "20% higher flow" turbo upgrade. It was $700 five years ago, and now you could probably get a real nice unit for that kind of cash. I did a few fuel pressure increases, as it was running leaner when I started, and I may increase it by 1 or 2 more psi just to stay on the safe side as I increase boost from 15psi.

Thanks for the props. Mods on a rock-stock motor and Felpro head gasket: Hybrid turbo, stock T3 turbine, TO4 V trim compressor Bosch fuel pump, AEM FPR, 370cc injectors Spearco intercooler Z31 ignition and ECU ScottyGNZ's stainless downpipe/3" mandrel bent exhaust/Dynomax ultraflow muffler Weber 60mm throttlebody Centerforce II clutch, working but slipping on launch. Initial timing is 20*BTDC. The MAF sensor was removed from it's housing and installed in my (larger) intake pipe, and this is how I run normal A/F ratios on larger injectors. I've got to get my used ClutchMasters clutch put in soon, I run the strip again in 2 weeks - I got the clutch from Shane, he ran low 12s, high 11s using it. I'll see if I can get my dyno chart scanned and uploaded on Monday.

Ran a baseline and did a little tuning on the dyno today. I was anxious to see how the trap speed calculations correlated to dyno measurements. My trap speed of 108 said I had 280hp to the wheels (the ET calculator shows only 250hp.) After a little tweeking, the DynoJet shows I have 313hp to the wheels, and 417 torque! Still running about 15-16 psi boost, I need to fine tune the boost controller to get rid of the slight spiking. But the A/F ratios were good, about 12.7:1 to 13.0 to 1, and nice and flat. I'm running the Z31 factory turbo ECU with a modified MAF sensor and SVO 370cc injectors.

I don't know what setup you have and what your goals are for the car. But to answer your question, it's the ECUs job to increase fuel with increased airflow - that's why it has an airflow meter. If you have a particular setup, and the item you are talking about meets your needs, then get it. But know what you are doing first, otherwise you will spend a lot of money and your car will not be any faster.

No. Not unless you know exactly what it does and why you need it. You'll be throwing your money away. IMHO, it has a very limited application.

Yeah, as I posting in your other thread, I got another low 13 with a 110mph, best trap yet, but my clutch is what kept me out of the 12s this time. Instead of nursing it off the line, I gave it some RPMs and with the clutch fully disengaged, it slipped all the way through first and partly through second. 13.3 @ 110.

Well, I'm glad I made no predictions...for myself anyway. I just got back, and I finally tried to lauch the car like I just stole it...lo and behold, my clutch slips like crazy. The same Centerforce II that has served me well for 4 seasons of babying. Soooo, if I want to get myself a 12, I gotta replace the clutch. I'm going to stick my used CM unit in, hopefully I can get that elusive 12. BTW, I set a new trap speed record. 110 mph!!!

My take on a two step boost controller: First gear, or even second, I can't make full boost anyway, so it's pointless. My issue is either blowing the tires loose, or bogging, right at the line. My boost comes on smoothly enough that once I have traction, I don't usually lose it again.

I'm not making big power (yet), my Centerforce II has been very reliable and easy to use. No slipping under boost, easy engagement.

It's not a switch, but a sender for the gauge. It's located on the oil pan near the drain plug.

Pretty sure Shane had to run a spacer with his JWT 450 kit.

Wow, old skool man... 8)

Ideally, clipping should improve flow for a better top end, but it will slow the spool up.

It's a POS. It has a terrible spray pattern and it won't flow a significant amount of fuel. Truly, I am a cheap bastard on a budget, but I won't touch that.

Sounds good - headgaskets can be replaced. So far, these L28 motors have proven to be quite durable.

I may have one, plus clutch, you can have fo nothin'. $10 shipping will cover it for sure, I'll check to make sure I still have it. Or you could come up to Denver and get it - be cool to get together with another Zhead.

I was just referring to the fuel rail. If your fuel cell has AN fittings, you will have to use them, unless it's tapped with pipe threads and you can replace the fittings with barbs. Since most stainless braided hose is AN sized, and you want to pass an NHRA technical inspection on your aftermarket fuel system, you pretty much have to use the AN stuff. Otherwise, just use the normal OEM stuff.

Huh? How are you going to get even close to a good fuel mixture without sensing load? What you are saying is, when you rev your motor up in the driveway, you are going to fuel it like WOT in third gear? No, you need a MAP sensor.

Stony, I can't believe there wasn't something wrong with that stub axle. There seem to be many here that run that fast with 240 and 280 stubs that aren't breaking that often. What would happen if you just replaced the 300ZX stub with another, magnafluxed of course, and give it one more chance? BTW, the urethane control arm bushings are working well, aside from an occasional squeak. Those and the new diff mount really give the Z rear a more solid feeling on a good launch....