To build the ultimate 3.4 DOHC: Turbo DYNO NUMBERS

[Shaun41178(2)]

keep an eye on your air/fuel ratio.

What timing are you running at peak tq? Also what is your timing at redline?

[fieromadman]

AFR has been good. I'm a little rich, like 10.7, around the 4000 RPM mark, but then it goes to like 11.5-12.0 for the rest of the RPM band. Still have a lot of FINE tuning to do with the air fuel, but nothing terrible. As for timing, I'm running about 17 or 18 degrees at 4500 RPMs (peak torque) at 8 psi, and it retards with more boost. I'm running about the same at 7000 as well. When it comes to tuning ignition timing I'm pretty much an idiot. You guys should help me out. All I knew was the 24 degrees I was running at 5 pounds at 7000 rpms was TOO much.

[Shaun41178(2)]

why was 24 too much? Its not too much boost, and were you getting detonation or pinging with 24 degrees? if not then the timing is fine.

So your timing is 18 degrees at peak tq now with 8 psi, you want to increase timing as rpms go up even when at 8 psi. You need to maintain cylinder pressure so in order to keep pressure up, youneed to increase timing as rpms rise.

take screenshots of your timing tables vs boost and rpm, and post them up.

[fieromadman]

I will do that. I didnt have any noticeable pinging or anything. I just wanted to be safe. My knock gauge was flashing full knock in the higher rpms before though. I know that the gauge isnt the best and most useful thing in the world but its really all i knew to go off of...

[The Dark Side of Will]

What exactly is your knock gauge?
Now you're getting into engine management questions. You need datalogging to really assess whether an engine is knocking or not.

[Atilla the Fun]

not so. The MSD thing is as good as anything.

[fieromadman]

This is my knock gauge:

http://cgi.ebay.com/ebaymotors/Knock-ga ... arQ5fParts

And the problem with data logging is that the Haltech doesn't have a knock sensor input. Data logging with the Haltech E6K is kinda a waste of time.

[fieromadman]

Here is a screenshot of my timing table. I had to make it in excel otherwise you would have had over 10 screenshots for each rpm range in the Haltech. I made one of my fuel too. I'm going to use these as good baselines to adjust off of and then put the values into the Haltech when they are evened out and make more sense. It helps me to figure out exactly what RPM range I'm rich in by viewing the fuel tables this way especially. And as far as the most recent ignition table changes go, I did them in about 5 mins on the side of the road, so yeah.



If anyone is REALLY interested I could send the excel spreadsheets as well.

[Shaun41178(2)]

pulling timing lower in the rpm band will help with spool. Less gas will be burnt in the chamber and will actually burn as it is leaving the cylinder and into the exhaust manifolds. This can increase spool up.

24 degrees is a lot, but it just might be what the engine is capable of running at. Supras run low to mid 20's at full tilt on the stock computer. It has knock sensors too that pull timing if it picks up knock though.

have you verified your knock sensor working? Have you tapped on the block to see if the sensor is picking it up and relaying the signal to your gauge?

Usually with timing, you want to increase it as the rpms go up as the engine needs more timing to burn the fuel.

[fieromadman]

The knock sensor does work for sure. It lights up like a christmas tree when I'm at full boost. It actually makes it useless. Therefore I am lost as to where the timing is ok and where it isnt with this engine. I will keep in mind what you said about advancing timing as rpms increase and change that.

I think the knock sensor lights up like a christmas tree because of all the valvetrain noise that this engine has especially in the higher rpms. Other than that who knows.

On the other hand the car is running 11 psi successfully right now. The air fuel is safer and more consistant than it ever has been. Its a steady 11.4-11.6 the entire time at full boost. Cruising still needs a bit of work, but its still pretty damn good. I would have had it running 14 psi yesterday but I need to change my wastegate spring. I also need to install my catch can.

I recently put in a starter from a 99+ 3400. One of the most inexpensive (45 bux for my used one off ebay shipped) and worth it mods that I have done to my car. It's a gear reduction so it is smaller and MUCH lighter, and it seems to crank the engine faster than my old one. Not to mention, it sounds good!

Before I put it away for storage I will get some videos and pictures. The car is pretty fucking fast on 11 pounds. So far I'm pretty happy but I know it has more in it. 3rd gear is just chewed up like it were second with the N/A setup. Anyhow... someone should come up with a good timing table for me. Haha

[Shaun41178(2)]

is your knock sensor lighting up like a christmas tree at idle or at no load conditions or at light cruise conditions? if not, then its not valvetrain noise its hearing as that would be happening all the time. Its probably knocking then. thats why you bought it the thing right?

Also the more you turn up the boost, the more you have to pull back the timing. so in essence you can't run 24 degrees of timing at 14 psi like you did at 5 psi.

at 14 lbs you might want to pull timing down to around 14-15 degrees at peak tq, and then run around 16-17 degrees at redline to keep it safe.

[fieromadman]

Shaun, that sounds like a good place to start. And no it doesn't knock when i'm idling. When I'm cruising I see small amounts of knock but nothing like I do when the RPMs are up. It doesn't matter if I'm in boost when the RPM's are up or not its still lights up. I really don't think it's knocking but who knows?

[Shaun41178(2)]

pull the plugs and that will tell you.

so in essence, even when not at boost and no load or light load, if you have the rpms up at say 4500 it will show knock?

[fieromadman]

Yes that is correct about the gauge.

What am I looking for on plugs to be a clue of detonation?

Also, just bought new tires for the rear. Nitto NT05's. Thier supposed to be bitchin tires. We'll see. They were $303 shipped to my door from discounttires.com. Size is 245-40-18, 10 mm wider than the current ones on the rear. Might need some 5mm spacers. Damn that stock Fiero spring perch location. Here's a link to info about the tires: http://www.nittotire.com/#index%2Etire%2Ent05

[Aaron]

I put a nice set of Nitto street tires on our Camaro (Forgot what number exactly), but they are fucking awesome on dry pavement.

[Honest Don]

Yes that is correct about the gauge.

What am I looking for on plugs to be a clue of detonation?

Also, just bought new tires for the rear. Nitto NT05's. Thier supposed to be bitchin tires. We'll see. They were $303 shipped to my door from discounttires.com. Size is 245-40-18, 10 mm wider than the current ones on the rear. Might need some 5mm spacers. Damn that stock Fiero spring perch location. Here's a link to info about the tires: http://www.nittotire.com/#index%2Etire%2Ent05

they should fit as is. I've ran 245's before without trouble. Also, Nitto's tend to run just a little bit narrow for a given size

[Atilla the Fun]

You can desensitize the knock sensor by wrapping the threads in teflon tape, by not installing it as tight, by installing it farther from the cylinders, by using brass fittings between the sensor and the engine, or by any combination of these.

[fieromadman]

Good to hear about the tires. I still kinda wanna add a 5mm spacer anyhow because the rims could be placed more towards the outside for better looks anyhow. I'm thinking that I can get away with a 5 mm spacer without changing the studs. If not oh well, it's not that hard to get longer studs installed in the rear.

About the gauge, I may do that. It probably is too sensitive.

And again, what am I looking for on the plugs as a sign of detonation?

[Atilla the Fun]

On the plugs, tiny specs of aluminum mean that detonation is damaging the pistons.

[Shaun41178(2)]

the specs of dark on the white ceramic part of hte plug. Or a melted ground strap or broken insulation would be a good determining factor as well.