Thanks for the "tech" of what I said. Call me when you are bored. I'm sitting around on the computer doing NOTHING!

Mikey

 

A local dealership warner in hummelstown pa., had a fp red evo that while on a test drive the rod decided it no longer wished to be in the engine! So what im gathering is you need built bottom end for this low end torque little monster turbos! yes? or no? well built to make it more safe? Cause after i make some more power im going little turbo to enjoy my car.

 

I have been making over 500hp on my stock motor for over a year and never had a problem. And I drive my car hard, 24/7 365.

Just took the motor apart to build it and there was no wear on the bearings or anything. I think as long as you keep tq below 450 and have a good tuner that won't push the timing to far, creating a lot of cp, then your motor will hold up just fine. I had full confident in my motor, however I want more HP

Mikey

 

I wouldn't fear the torque capability of these types of turbos.

Just use RPM based boost control and limit the peak boost at the low end. Use boost to keep torque flat out to redline and end up with a car that has a more tractable powerband.

350-375 ft-lbs from 3500-7500 RPM on a stock block will last and still be damn fast.

 

500hp/400tq is perfect for the stock motor and a great street car. Don't be scared! However I would stay with a Red or larger. Don't want to load up below 3500k... There have been a lot more Green cars blow up on 50-75 less hp... I think the load down low is killing the rods. I would even push a Black to 575hp on a stock block and feel fairly safe about it!

Mikey

 

Yes, your math is way off. Don't assume all gasoline is 14.7:1 stoichiometric, in fact there are very few that are close to that.

If .86-.87 La scares you I like to run Q16 at .90, in fact Q16 doesn't pick up power till .88 regardless of what VP claims. I prefer to run 93 at .87-.88, C16 .85-.86

My question to y'all is why do you run your cars so effing rich they rich knock?

What is knock, exactly? Why and when is it bad?

What is 'too lean'? At what point does imminent damage occur?

Stay tuned for another episode of internet mythbusters

 

Of course the standard disclaimer applies, don't try this at home, stunt performed on a closed course by professionals etc.


Last year, car was on C16, that is the ACTUAL AFR based on VP's published stoich value for C16.

Made two hotlaps at the strip with the fuel pressure regulator hose popped off, car was lazy and down 50 HP or so but not an issue as the driver was having problems getting it out of the hole right.

Ignore knock activity on launch and first gear as its due to accel rates, that is not actual knock.

Popped hose back on and made several more runs.

Camera scoped bores and head the next day, no damage.

Same engine as in dyno run and log on first page, only thing done to this engine since initial assembly is cam and spring swaps; head, pan, front side has never been apart.


So, again, what exactly is too lean?

In my opinion mild detonation is not harmful unless you allow it to progress, and preignition will kill your engine in a heartbeat. And end-gas detonation does not occur when there is no fuel left over to produce end-gas pockets. Think about that for a moment.

 

You can't burn fuel that isn't there... You can lean it out until you put the fire out and that's what your log shows. If you had done the same thing @ 14:1 AFR you'd have a new 2.3L we could all read about.

You did that on c16... much different than doing that on pump gas!

Thank you for sharing Robert.

 

Why is it different?

Where did the fire go out?

Those are full runs, look at the time from launch to 4th gear shutdown.

It was down on power and that's IT, no misfires, sags, etc.
I don't stay in the throttle if its misfiring.

 

Don't be so sarcastic. Octane, that's what's different. 93 compared to 117.

I've done the same on the engine dyno on an engine that is not knock limited (whether it's mechanically limited or by the fuel) Doing AFR sweeps from 12:1 all the way to 18:1. You can read Heyward's book and find examples in the text that will support my findings.

By not injecting the required amount of fuel you're not generating the cylinder pressure rise that you would with a fuel mixture near 12:1. If you were to log EGT's or cylinder pressure while varying AFR during a steady state full load pull...you can see the EGT's rise while leaning it out...and then they reach a point where the EGT's begin to fall again. (That's what I call...putting the fire out!)

Again... you were running c16... it can cover mistakes like this that would otherwise be costly.

 

Not being sarcastic, as an example of how meaningless Research or Motor octane ratings can be look into the Honda F1 engine program from the mid-80's. Limited by rules to test at 100 octane yet they ran 4.5+ bar boost in qualifying and also ran very very lean (at reduced power) at some tracks after the fuel qty rules came out. How about methanol puller engines? 200+ PSIg charge pressures, no IC. Octane seems to matter most to the test engines they determine octane on, not modern designs. If you're running in semi-stratified or full stratified charge conditions all the 'rules' seem to go out the window. Look what is happening with the current GDI setups.

Not disputing the fact heat goes up and down when you cross stoich for that fuel, or that power suffers if you go too far rich or lean for a particular set of circumstances, my question is when is it 'bad'? The only answer I've ever been able to say for sure is 'when you get something in the chamber so hot it causes preignition' at that point your engine is fuct in a very short period.

 

Good info guys. I'm going to stay away from this Ultimate Pump Gas Turbo until I get a built bottom. I've made 495WHP/435TQ but the torque was not produced that low in the curve. I'd like to get this turbo and push it to kill mode, but I have too much invested in my head, turbo, etc. to have engine debris ruin it all. Looks like I gotta shop for a built bottom.

 

All you ever are in your posts is sarcastic.

Your response was like making fun of your wife and then saying "just kidding!!" when she gets pissed at you.



- Bryan

 

nice one Bryan!

Mikey

 

The hottest incylinder temps are going to take place on gasoline around the 13:1-14:1 range. Leaner and there isn't enough fuel to put the heat in there to kill the engine. Richer and you have more then the minimum air that then absorbs more heat from the combustion event and cylinder temps drop.

I see Scott's point though that lean doesn't always lead to engine damage. I've personally ran 13.5:1 down the track with maxed out injectors years ago. Stock block 4G63. Nothing happened to the motor. Knock free on 110 octane leaded fuel. Tossed larger injectors in, got the AFR down to mid 12s and picked up 4mph.

"Bad" in that cse was just a loss of power and not engine damage.

On low boost, I'm running 12:1 on 91 octane without a problem. Car loves it, very clean burning (visually anyway) compared to most EVOs I've seen in the area.