dcg9381

I'll adjust my AFRs for ~11.5 or so. If the gasket comes in, I should get it back together that day.

I can buy 100LL octane AV gas here about a mile away at just over the cost of premium, but the lead isn't good for my wideband. I may run it anyway just to get the things tuned and provide a margin of error. The SRT-4 guys also swear by an additive called "torco" which allows them to flip the 100 octane timing switch without issue.. May try that also.

My air charge sensor is in my manifold, I tapped the spot where the stock cold start injector was. It's a GM free element sensor.

I was running 93 octane.


I trust your judgement on tuning, Rick - the fact that you've kept a stock 22RE together at 170 hp is amazing... Anyone wants a bolt-on bang for the buck mod, talk to fullboogie....

Full Boogie

Darin, which wideband are you using? I have tuned cars on leaded "race" gas using an LM-1 and the FAST widebands......Them along with a few others claim to be safe with leaded fuel, diesel fuel and alcohol/methonol. This is why I use the LM-1, I rent this unit out to customers that want to tune most of their engine themselves, and a replacement O2 from Precision retails at 80 bucks!


Later

dcg9381

I'm using the LC-1.
It can be used with leaded, it just "wears" it about 10x faster than unleaded..

Full Boogie

I have heard the same thing about many O2's, but have lasted going on 10 years. Your LC-1 basically uses the same sensor as what I use, go get yourself some AV gas so you don't hurt your engine again, and tune away. If and when it goes bad I will sell you a sensor....cheap, besides, I'm not saying run leaded fuel all the time, just when doing an initial tune on a new set-up. I know how weird it feels to have a bunch of money in something then going out and tuning it, getting to 100% throttle and watching the boost come up and pray nothing happens......some guys are almost annoyed how conservative I am on first runs and making them put $5 per gallon fuel in their tank before I'll tune it. It hasn't happened yet, but when a guy dumps 20 grand in his racecar for his engine/turbo/computer set-up and wants you to tune it, you don't really want to blow it up!

Later

dcg9381

Def blew the HG.. #4 and looks like #3 was leaking too..
Photo is big so I'll link to it instead of posting it:
http://lakebox.dnsalias.com/photos/1...ebuild/hg1.jpg

Bill

Are you going to have the valve clearance to run AV gas, seeing that it is leaded?

Isn't the lead build up on the valves going to couse some serious issues?

dcg9381

Bill, I don't think lead will build up on the valves.. Lead is pretty soft. New valve seats are harder than the ones in factory v8s back in the 1970s. The lead is actually good for detonation also...
We're not talking about running this truck around on leaded all the time, we're talking about a tankful to give me some safety factor if i want to tune it to peak.

I'm also installing a 38mm TIAL wastegate, which should eliminate boost creep.

dcg9381

An update on my turbo project:
I started tuning this thing mid last week. Basically my primary goal was to get the air/fuel right and then play with timing. Megasquirt has the ability to "autotune" - which I found useful, but only after radically slowing down how fast it reacts rich/lean conditions.

Once set, you basically try to go through a number of throttle position and RPM combinations, keeping the throttle as steady as possible for each. Obviously you can't do this perfectly, so you smooth out areas that don't look right manually.

For those who haven't seen this - the fuel map is VEbin.
Y-axis is engine load, x-axis is RPM. Anything over 100KPa is boost - this is just an example:
http://lakebox.dnsalias.com/photos/1988%20...ock22remaps.jpg

You can set air fuel targets also - basically I choose 12.4:1 into boost. Below boost, 14.4:1.

After I got that right, I decided to tune into boost. My turbo is a bit large - a t3/t04b, my understanding is the wastegate was setup for 6psi.
I'd start to boost at about 2k and be at 9k by 4500, which is a little late and indicates that my turbo is too big for what I want to do.
I retarded timing, but I hit detonation at 9psi a few times (just for a second). Logs indicated I was doing a bit more boost than that. I checked the interal wastgate acutator, rigged it up to my leak down tester and it wasn't opening until 20 psi. That's Bad.

As it turns out, this was enough to blow my HG. I did a leak down on #4 and had air in the cooling system.




This was a bit of a bummer... I reviewed my logs and found that I was hitting over 9psi.. Not good.. I also figured out that megasquirt can't retard past base timing. That means if you mechanically set your base timing to 10 BTDC, you can't go lower than that. You need to set it to 0 BTDC and advance electronically at idle.

Things to correct:
1) Base timing issue. Be sure to confirm that advance / retard works with a timing light.
2) Boost creep. I added an external wastegate to my setup, set to .4 bar ~6psi, until I'm tuned.
3) Drop my AFR to 11.5:1, per Rick's suggestions (info@fullboogie.net) - he's done a lot more tuning than I have.

Bumpin' Yota

So wait the OEM wastegate on that turbo wasnt opening untill 20psig? Could there have been a leak from the compressor outlet to the WG actuator, or is the spring just that BIG on the WG actuator? Or is the hotside just flawed in that the internal wastegate cant flow enough?

dcg9381

No leak. I put 20psi (via leak down tester) into the WG actuator itself.. It doesn't feel damaged, it feels like a big spring.

The hotside has a larger than normal internal gate.. I could have just replaced the actuator.

Bill

Is there a limit to how much you electronically advance timing? Base timing sets the relation between the crank shaft and the cam, and thus the valves.

So if you set the base timing to 10* BTDC, isn't it going to run slightly different than setting it to 10* electronically with a 0*BTDC, because of valve position? Or is it negligable?

dcg9381

There is a limit with a distributor, you could always trigger way to early and actually have the spark distributed to the wrong cylinder.. Practically, don't worry about it.

Electronic and static timing of 10 BTDC should be the same... I was having issues setting 10 BTDC electronically, so I'll sort that as soon as it's back together.

tampabayota

you guys are loseing me!!!! I dont know anything about this stuff and your scraring me.My turbo is being shipped today from jason at tec turbo finally.Motor will go in right after x mas. can you break this down to laymans terms as to what is going on.Darin did you blow the hg after your build or before?

dcg9381

tom, don't worry about it... The TEC setup you're getting will work fine with the 22RTE.

My motor has significantly higher compression than yours, but not as much as a 22RE. I have to sort out the timing and fuel - things that your ECU does for you automatically. If you don't get them right then you can have issues like I just had.. It's one of the downsides to having a "flexible" ECU.

In layman terms:
1) Air/fuel (A/F) = I get to determine how much fuel I give the motor.
2) Timing = I determine when to trigger the spark plug. Too early and it can detonate. Too late and I lose power. BTDC = before top dead center, this is the # that you typically see on your timing light. With turbo motors, you start giving it less timing as you increase boost.
3) Higher octane - race gas - AV gas - these fuels are less volitile than standard pump gas. As such detonation is less likely.

tampabayota

thanks darin any help i can get ill take!!!