cygnusx1

I see, so it probably became apparent to me because I have increased the turbo's ability to spool up and now it blows more air at X rpm-X psi than the motor can ingest at X. Very cool....actually hot, because the turbo moves outside of it's efficient range. It's a T3 Turbine with a TO4B "Super-V" trim (dont really know what a "super-v" trim is other than it's a Garrett spec). I don't feel it's a huge problem because I just have to pedal it until I get to about 2800-2900 rpm's, have it floored by about 3000, and it really puts you in the seat with no surge at all at the current, 15psi. I am not going to further tighten the BOV, in fact, I'll loosen it and just drive it right. Bottom line, a nice free flowing intake WILL change the performance of the turbo noticeably.

If you want to rattle can it for better photos, just state that you did clearly.

Low RPM lugging IS NOT my driving style people!!! I have never owned a motor larger than 2.8 liters. All my other motors besides the Z were 2.0 or less. The ONLY reason I brought it up was because I DID NOT get the surge before I switched to MS-II and a Cone air filter right on the compressor. The ONLY reason I drove into "banned driving style" territory is because I was AUTO-TUNING my VE maps and needed to drive in that range. I dont lug my motor!! I love the way this accel curve of this car is exponentially up with speed. You can see it in the datalogs. It accelerates faster, the faster it goes! Back to tech talk. In the three years of driving this same engine and same turbo with factory EFI at 15psi boost, I never got the surge. What changed it?

Does not matter. Works either way AFAIK. They changed somewhere in the revisions but I don't think it matters in actual use.

Picking motors is like picking girls. To each their own. If you're lucky you can have one of each. If not, identify, your goals, your likes and dislikes about the ones you know, your cost objectives, and go get one. This is bordering on a "Best" thread already.

Yeah thanks but I was wondering if anyone knew about his head-building skills. You know, does he use a hammer and file like me or does he use a machine shop with knowledge, does he measure valve stems or does he just throw them back in.... I was looking more for a personal reference than feedback from ebay. Thanks anyway.

Anyone here ever do business with Ebayer, "datsun-parts". I was considering buying a "rebuilt" head from him but I don't know how his handiwork is? http://stores.ebay.com/datsun-parts Thanks, Dave

That car had the aerodynamics of a playing card! A little more science would have helped.

You can use a wideband to datalog AFR's to a computer and analyze it later. It doesnt necessarily have to tie into the factory ECU. The only problem is that you might not have any way to tune out the misfire. Maybe it's time for you to get a standalone fuel/spark system and ditch the factory EFI and AFM. By the way my turbo motor idles at 24° btdc and maxes out at 41° btdc by 3000 RPM. I decrease to 24°btdc max by 15psi boost.

Have you tried tuning with a Wideband O2 sensor? That might reveal what's going on.

My car is running well now but I am doing the trans swap soon. If it is all back together from the Z32 trans swap by then, I will join you's too. I could always hitchhike or take the WRX .

The pads backing away from the rotors due to vibration could cause a little of this. Warped rotors? EDIT: Jon beat me to the punch. Also wheel bearing play?

Alright! Another drill, hacksaw, and rat-tail file guy!!! We don't need no milling machine! Just give us a week and we'll make you a semi precise billet whatever. Nice handiwork.

LOL, yes I know flooring it at 2000 is not good driving (on small liter motors). Sorry I made it sound like I do that for fun...I don't. I am tuning the car and was tuning the high load/low RPM parts of the map for driveability. I just noticed the flutter there where I had never noticed it before the MS-II and the intake reconfiguration. You bring up a great point that actually went right over my head. I used to have my BOV (TurboXS Race Valve) recirculated back to the compressor intake and now it's vented to atmoshpere. I wonder if that's causing the flutter....hmm great point Tony.

Too tight is only good for some things....not for crank pulleys.

Dammit, can you mail me back my briefcase pleez!

Yeah once I get up above surge territory it accelerates like a jet fighter. You are right, why spend the $$$ just to bring the boost in slower when I can learn to drive around it. My only fear is that if I surge it enough, I will be needing a new turbo. Looking on ebay though, I see that turbo prices have come way down in the past few years so I am not too worried about shelling out too much. Turbos are even cheaper than the EBC's! In what way would a performance turbo cam make a difference in this situation? Would the engine VE go higher in the low range, high range, or both?

I worked for a BMW dealer when they came out and I will never forget the opportuity I had to drive one of those at the age of 16 or so. Love them dearly to this day. I have now driven every release of the M3 but only that one does it for me.

Time to get out the calipers and take some measurments before you got bonkers. Make sure the hole is not much smaller than the factory pulley. You dont want to press it on and have to pull the motor to get the pulley off later.

I grew up in the Bronx. My whole neighborhood was a dumpster. When I needed materials, I would wander into an abandoned lot where dumping was a part of life and scrounge. Nothing beats finding free stuff! Bike parts, car parts, road signs, hoses, plywood, all kinds of metal, sometimes we even got radios and other electronics. We actually made a roller coaster out of milk crates and old lengths of lumber we found.

Good news is that by installing the MS-II and the larger injectors I was able to get my TO4B "Super-V" to spool up quicker. Mainly due to better fuel/timing maps and a nice BIG free flowing intake. Bad news is that if I floor it in fourth at about 2000 RPM's the boost builds to about 10psi by 2500RPM's and I hear the wild goose surge flutter sound from the BOV, and the boost gauge goes bannanas. My first instinct was to add a washer to the BOV spring but then I realized that the increased "flutter pressure" was BAD for the turbo blades and bearing. I use a grainger style {ball-spring} boost controller that is set to 15psi. Is it time to go for an electronic boost controller or is there another relatively simple/budget fix? Please dont suggest not flooring the gas pedal. That aint gonna happen! -Dave "Turkey Call" LISTEN NOW: http://www.wildturkeyzone.com/gobbles.wav

Pretty much the only place in the country it's raining is here today Oh well, it's still a day off.

Update, I have not yet installed a 12v filter but now I carry the laptop equipped with the firmware ready-to-load just in case. I have had no more issues in about 300 miles of street tuning and cruising. It is running great. I think that the laptop must have killed the firmware because it's the only thing that I can remember being strange. It locked up once or twice while connected to MS-II and maybe it zapped it enough to make it unstable.

Wow, glad you were able to pull yourself together enough to crawl out of the wreckage and find your way back to us!

I agree. It runs, all the parts are there, take it apart, clean it up, paint it, put it back together with a few custom touches, and you are ahead of the game. Welcome to HybridZ. Send Pics!!!