cygnusx1

Advancing the timing allows more time for the fuel to burn in the cylinders. This uses up more of the fuel mixture thus dumping less "live mixture" into the exhaust. Less "live mixture" in the exhaust means lower EGT and Turbine Temps. Advancing too far will cause the ignition to start when the piston is too low in the compression stroke. This will create a much higher dynamic compression ratio and cause PING. I think.

This must be the patent...... http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=6,745,568.WKU.&OS=PN/6,745,568&RS=PN/6,745,568

Sounds like fun...I live on a road resembling a track. 75% of my commute is on roads that wind and pitch like a track. I am hoping that hours and hours of commuting "practice" on these roads has made me a natural line picker, apexer, and overall car dynamics natural. We will see. I hope to have the confidence to push the car, but also to have enough sense not to overpush the car. The area in which I live could easily be mistaken for a tarmac, pro rally track. Yes, there are jumps also.... I save those for the WRX.

Hey now that oxygen isnt mixing with your exhaust, try connecting your oxygen sensor again. Since moving the timing ahead, mine runs good with the O2 connected.

Oh, I see. Thanks for the tip. It could be the case, the pulley looked good when I painted it and put it on but you never know. It does have 110K on it.

Hmm, how would that move? The timing pulley is keyed, the scale is bolted to the block and piston one TDC, can't move relative to the keyway on the crank. The only error that can be made is by picking the wrong tooth when sliding the oil pump in. Ultimately that wont matter however as long as timing jives with a timing light and the distributor bolts line up at factory timing. I haven't yet built a Z motor so I may be missing something You are right though, confirming TDC with a tool would not be a bad idea.

Hey, Alex how are you? Your turbo is putting down some good power and I don't want to blow the motor all to bits. I think I will settle for about 12psi or so and use the street gas; 92. I know it works for 14psi on the street. I will be out of the cage Goals: 1) Learn to drive track 2) Keep motor intact 3) Stay out of the tire barrier after Big Bend, on the inside. (if you know Limerock you've seen cars in that barrier)

I just want to follow up. I brought my base ign timing from 22 to 27 btdc and the turbo glows MUCH less than before under the same set of driving conditions. I also feel I gained a sh'load of torque from 2K to 4K rpms. I luv it. Idle has also improved. Engine GROWL has improved. She's running like a monzter! Thanks for the tips!!!

Slowing down may be a good thing the first time on the track with my baby. Yeah, I suppose a "resistance to ignition" (octane), increase would yield either a slower burn or a delayed ignition causing less power. I think I will just take my timing back to near factory and drop the boost down to about 12psi to be safe while I learn to brake, turn-in, apex, and exit corners properly. I REALLY would like to keep the car in one piece for the duration so I will be "slow" while I learn to drive for sure....at least this time.

Well, yeah I agree, If I can guarantee 95-100 octane in the tank I will leave all the parameters alone and drive it how it is. I just was thinking that an ounce of prevention could save me a flatbed fee back to my house from the track.

I am running 27 at idle now and it is SUPER torquey. I may be near or at detonation but it sure feels right. 83 motor. Stock EFI. FMU@60psi fuel@14psi boost...I am thinking of backing down a few degrees for piston preservation....I dont hear any ping but that doesnt mean it's not there. At 27, the idle is stronger and the turbo seems to run cooler also.

Off topic sort of. My turbo used to come home nice and red. I was running 13-14psi boost with 60psi fuel from an FMU, and stock timing and EFI. I advanced the timing from 22 to 27 and it barely glows anymore. This tells me that it's not only mixture that effects turbo temp. It's the efficiency of your burn. I figured it must have been running a bit rich and burning leftover fuel in the turbine. By advancing the timing, it burns more of the mixture in the cylinders where it should, thus keeping turbo temp down. Just an observation.

I am about to sign up to bring my Z to Limerock Park for a time trial session on the road course. Just to be safe I was thinking about backing my timing down from 27 to about 25 and maybe turning the boost from 14 to about 12. I was also wondering if any of these "octane boost" additives really would add a margin of safety; reducing possible detonation under track conditions. Race fuel would be ideal but being a street car, I run 92 octane pump gas. The time trial is with EMRA at Limerock on Oct. 29th. I think my Z is going to fall into the Tuner class. I have never driven on a track before but I cant wait to not have to worry about mail trucks, school buses, oncoming traffic, and pedestrians.

I built it once. I can build it again. Let me have fun breaking it!

If you can, put it in front of the I/C. In my case, I selected a cylindrical shaped filter by opening random boxes in the auto parts store. I mounted the filter right behind the left headlight. If you look up from underneath the car, in the wheel well, you will see there is a nice "box" area that is somewhat protected from road debris and splash up in the fender against the rear of the headlight bucked. I fit a 5" round by 6"long filter up in there and hold it in place with a metal bracket bolted to the tow hook bolt. The 2.5" intake hose runs from the filter, down under the frame rail in front of the sway bushing, and back up behind the radiator to the AFM and Turbo Inlet. In this location, it gets cool air and it does not block front end airflow. Getting the 2.5" tube up behind the radiator required oval tubing (round steel pipe and a vice) for a short section. If you want some photos of this setup you can start here. http://www.hvmp.com/dc or I can take some updated photos and post them. The bellypPan needs to be left off or modified for this to work. I am not sure if the added length of intake is offset by the cooler temp of intake air in my case. Whatever the case may be, the car runs strong.

Just an FYI. I advanced the base ignition timing to about 26 deg and it makes a world of difference in the 2-3K rpm power band. Lots more torque and smoother power. It also runs VERY strong from 3-5k rpms. I am maxing boost to 14psi and adding about 60psi of fuel under boost to the stock injection with the FMU. I must be near the point of no return because stepping on the gas makes me laugh and grin as if I just found a winning lotto ticket. I dont hear ping but the engine growls a bit more now under load. I really dont ever rev past 5500 rpms and dont race so I think the pistons should be safe. If not, I will let you know and I will upgrade the internals and the FI and consider it "taking one for the team. " Too Fun!

I think it's cool. Definately "outside the box". So what if it's an expensive way to make a little more power? Follow this: One guy wastes $60,000 to buy an exotic car to run 12.5 seconds. Another guy spends tens of thousands of dollars and hundreds of struggling hours to make a cheap, ugly, sedan with a "park bench wing", and a 1.5 liter motor run as fast as the $60,000 guy. A third guy builds a $5,000 Hybrid Z that rivals both of them. Who is right? ANSWER: The Hybrid Z guy of course Get my point?

Bump. Anyone?

Here is a way to improve your 1/4 mile times. http://www.ratsun.com/videos/9.35.mpg <---This belongs to a HybridZ member.

Skip the clutch. Why would you ever want to run with the supercharger turned off??? Sounds like a fun project keep us posted.

The only time I have ever heard ping in my Z was with the N/A original motor in top gear trying to stay with an early 90's 300ZX on the highway. With this 83 Turbo Motor I run 13-14psi, 100% stock EFI and FMU, like bast said and I have never heard it ping. I also have heard that ping can be difficult to hear when it's borderline. When we had my friends modded WRX wagon on the four-wheel dyno at TurboXS, they were hearing ping with a special listening device. We couldn't hear any ping standing outside the car.

Hmmm about 2mpg less. Hmm, I could probably sell the O2 sensor to pay for the increase in fuel consumption. I only do about 3K per year on my Z. That's weird...I used to be a donating member but now I'm just a member again.

Over the past few weeks I have been trying to tune the car using the stock O2 sensor, a digital multimeter, and the AFM. I got the car to run around stoich during idle and cruise. The O2 voltages flipped past 0.5V every second or so and the green LED on the ECU blinked accordingly. The car ran pretty good and idled pretty good but it wasnt consistent. It seemed to run good and smooth and then the next day it would surge and miss in the 2K-3K rpm and at idle. I already checked a dozen times for intake/exhaust leaks using several well known methods and havent found any. I decided to unplug the O2 sensor about a week ago and the idle smoothed right out and the surging during cruise minimized. I did have a lack of torque in the 2K-3K rpm range so I richened up the AFM a few teeth untill I got power back in that range. Now it seems to drive better than it ever has. There is only a tiny bit of surge/miss in the 2k-3k when boost is climbing through 10psi. This is without the o2 sensor, and with the TPS connected. I can't yet comment on fuel mileage but I suspect it has suffered. One other point. About 2 minutes after a cold start, it runs like "pooh" for about 1 minute. After that it runs normal again. This was the case both with and without the O2. Bottom line, I think the tune of the EFI has a much greater effect than a small leak. However, small leaks should be fixed before they create bigger problems.

My 83 ZXT motor used to fire up INSTANTLY from any temperature. Since I installed the I/C, the TO4B, and the 60mm TB it takes two or three cranks and stumbles a bit before actually finding happy idle. I have no idea why it changed after those installs. Yes, sensors, switches, fastidle, signals, and wires, are all working as they were before. Maybe the extra volume of air between the AFM and the pistons, by adding the IC, causes a delayed AFM response at low rpm (cranking) speeds.

Run to the patent office! Dont walk. Sorry but I couldnt resist.