Seems to be a good Q for the forum........

Is it safe to run boost w/o retard on a 2.4? I am having problems with my GM reflashed ECU, so I was thinking about using a stock ECU and AFMU with my 310cc injectors and AFPR, I also have a SAFC, but have not messed with the adjustments.

Is this a good idea, or is there a need for retarding the timing, I have searched the members reg. and it seems there are quite a few people running turbo setups without anything to change the timing or at least they didn't list it.

I guess what I want to know is if the stock ECU would be able to pull enough timing for 6psi.?

Jason



USACi =>146.9db
14.88 @ 90.73MPH =>GM Charger, Motor Mounts, Catback exhaust

you dont want the car to pull timing, the more timing it pulls due to knock or intake temp robs power



1989 Turbo Trans Am #82, 2007 Cobalt SS G85

Quote:

you dont want the car to pull timing, the more timing it pulls due to knock or intake temp robs power

Yes, but you don't want it to knock either!

MSD Boost Timing Master. Check it out




I was a retard, and now I'm permanently banned.

You do want to pull timing for safety purposes. It doesn't ROB power. Remember that a better tune will allow you to run more boost reliably. Every additional pound of pressure in the combustion chamber is going to mean it takes that much less time to fully burn the mixture.



Cardomain|Myspace

Spotabee Racing wrote:MSD Boost Timing Master. Check it out

Man can this thing work for nitrous also? I'm sure it reads boost then starts to retard to whatever degree you have it at. Couldn't I hook it in some way to read the "boost" coming in from the nitrous also and retard off that?




N2O + Bolt-ons = 220Hp/250Tq

Coming Soon:HpTunersPro, EagleConnectingRods, WiescoPistons, 13sec2200

Question for you guys...

If you're running a lower compression, retarding timing wouldn't be that necessary because you are less likely to detonate (example: going from 10:1 to 9:1 compression)?



www.kronosperformance.com / 732-742-8837

You run lower compression so you can run higher boost safely. Timing retard is never going to be NEEDED, it is just a wa of more accurately tuning your engine. I'd do it, but thats just me.
Jamal, I am setting up my sunbird to spray using an MSD multistep retarder. If you are just spraying, this is a great option, if not I would go with a programmable ignition system. You should have switched timing maps that you can set up just like the multistep, but they overlay on top of the boost maps. It's pretty much an all-in-one system.



Cardomain|Myspace

Bballjamal (Cav-AtL) wrote:

Spotabee Racing wrote:MSD Boost Timing Master. Check it out

Man can this thing work for nitrous also? I'm sure it reads boost then starts to retard to whatever degree you have it at. Couldn't I hook it in some way to read the "boost" coming in from the nitrous also and retard off that?

In that case, I'd go with an MSD Multi-step retarder, or depending on your funds, you could always do the MSD Programable DIS-2




I was a retard, and now I'm permanently banned.

M I N I O N - Sinbird wrote:You do want to pull timing for safety purposes. It doesn't ROB power. Remember that a better tune will allow you to run more boost reliably. Every additional pound of pressure in the combustion chamber is going to mean it takes that much less time to fully burn the mixture.

Retarding your ignition timing will cause a loss of hp.

M I N I O N - Sinbird wrote:You run lower compression so you can run higher boost safely. Timing retard is never going to be NEEDED, it is just a wa of more accurately tuning your engine. I'd do it, but thats just me.

Just because you lower your compession ratio does no mean you will never need to retard timing, lol.

Retarding timing is simply a way do avoid detination, just like adding higher octane gas. The more air you stuff into a cylinder or the higher the ratio it is compressed to, the greater the risk of detonation is. To avoid it you can either use higher octane fuel that is more resistant to combustion from pressure/heat or you can retard timing which will cool down cylinder temps.


- 93 mph in the 1/8 mile
Member of J-Body Of Michigan.

Following Minion's post, you do want to run less spark advance under boost. Don't think that retarding timing robs power. That's a generalization which is not correct. More air compressed = more heat in the combustion chamber = faster burn time. If the air charge is preheated by the turbo, then burn time is further decreased. Best power is achieved when maximum cylinder pressure occurs around 12-15 degrees after TDC. With faster burn times, you create maximum cylinder pressure at the correct time by starting the burn later.

People use excess fuel instead of decreasing spark advance. This decreases burn time by reducing the heat in the chamber and by reducing the available oxygen. But it doesn't deliver as much power as a system with ignition control (less oxygen to burn = less power) and it wastes fuel. It also tends to pollute engine oil much faster than a well tuned spark and fuel system.

If you reduce the static compression ratio you reduce the heat created in the chamber during the compression stroke. It follows that spark advance doesn't need to be dropped as much when boost builds. But the other side of this coin is that cylinder temps (and consequently power) during the times when the engine is not under boost is also lower. Lower compression turbo engines typically have increased spark timing at 0 psi and below than their NA higher compression brothers.


-->Slow

slowolej, i agree with everything you said except saying that pulling timing does not cause a loss of hp. Using a higher octane fuel instead of retarding timing to avoid detonation will result in higher hp. For example, (i'm just pulling these #'s out of my ass for an example) you're running 6 psi on a 2.4 with 91 octane gas and get no knock but when you turn up the boost to 10 psi it knocks like crazy. So you retard the timing X degrees under boost until the motor can run on 10 psi without any knock. If you had instead of retarding timing just used a high enough octane fuel for the motor not to knock at 10 psi you would be making more hp.


- 93 mph in the 1/8 mile
Member of J-Body Of Michigan.

Quote:

slowolej, i agree with everything you said except saying that pulling timing does not cause a loss of hp.

Ok. I see what you're saying. The original question is about switching back to stock program for an NA engine, and the main point is that stock timing for an NA engine is just too much for running any serious boost, no matter how high the octane. Running 20-25 degrees spark advance at 8 - 10 psi in a 10:1 (for example) engine is just asking for trouble, no matter how much octane you put in the tank. You won't lose any hp by dropping spark. You'll probably save the engine.

But ya, once you get the timing close it's better to make some runs to see if more timing and more octane together improve the situation. It almost always does, but some engines really like a little less timing and lower octane. It's all about getting the peak pressure when the rod and crank angles work best together.

Sometimes it's hard to catch it, but too much timing can cause problems even if you aren't hearing detonation. The engine oil has to absorb the force created in the chamber and transferred through the piston and rod. When timing is advanced too much, the oil takes a beating. If you have an oil temp gauge you can see the needle rise when timing is advanced beyond peak power. And if the oil is heating up, the cooling system is also working harder. More heat in the head means more heat transferred to the intake air after the intercooler and more heat that will build in the combustion chamber. I prefer to avoid that when I can.

-->Slow

Skilz10179 wrote:

M I N I O N - Sinbird wrote:You do want to pull timing for safety purposes. It doesn't ROB power. Remember that a better tune will allow you to run more boost reliably. Every additional pound of pressure in the combustion chamber is going to mean it takes that much less time to fully burn the mixture.

Retarding your ignition timing will cause a loss of hp.

M I N I O N - Sinbird wrote:You run lower compression so you can run higher boost safely. Timing retard is never going to be NEEDED, it is just a wa of more accurately tuning your engine. I'd do it, but thats just me.

Just because you lower your compession ratio does no mean you will never need to retard timing, lol.

Retarding timing is simply a way do avoid detination, just like adding higher octane gas. The more air you stuff into a cylinder or the higher the ratio it is compressed to, the greater the risk of detonation is. To avoid it you can either use higher octane fuel that is more resistant to combustion from pressure/heat or you can retard timing which will cool down cylinder temps.

Way too pretend to dissagree with me and then restate everything I said.
You don't NEED to retard timing under any circumstance, just like you don't NEED to even run an intercooler. Eveyrthing you don't do is going to cost you in reliability and potential. If you perfectly tuned your fuel system with perfect timing, you could run a lot more boost than without the timing pull AND you will be getting better gas milage because you don't need to waste fuel to cool the cylinders.

I'm going to again say that retarding timing doesn't rob your horsepower, it allows you to have the same horsepower safely with a little more boost and less fuel consumption.

Really, once you hit 91-93 octane, daily drivers don't have many other options for getting the right spark timing than manually pulling it.

The cool thing about programmable ignition systems is that you can have alternate timing curves for different grades of fuel if maybe you wanted to get rid of some of the retard and run 110 octane at the track like you had said. Basically, you are right about that with the octane ratings, but that doesn't mean what I said was wrong.



Cardomain|Myspace

If you pull out timing, you will loose power.




275hp & 306tq - 1999 2.2 ohv
13.2 @ 108 mph
-1996 2.4 liter + Turbo + Built motor + Torco + More boost = Lots o' Power
-2000 Mustang GT + 2004 Cobra motor, Whipple 2.3 supercharger,
built rear-end,Dodge Viper spec T56 6 speed, bolt-ons = wheelies at the track!!!!!

i dont pull timing and I am at 10 psi



LE61T PTE6262 Powered

Pulling timing doesn't always mean losing power. You could be getting spark knock at higher boost pressures, which would rob power. Being on the edge of knock and detonation with timing doesn't mean its the highest HP. The best timing for HP is one that's set on a dyno.


O noes!

M I N I O N - Sinbird wrote:

Way too pretend to dissagree with me and then restate everything I said.
You don't NEED to retard timing under any circumstance, just like you don't NEED to even run an intercooler. Eveyrthing you don't do is going to cost you in reliability and potential. If you perfectly tuned your fuel system with perfect timing, you could run a lot more boost than without the timing pull AND you will be getting better gas milage because you don't need to waste fuel to cool the cylinders.

I am not pretending to do anything, i still disagree with you. You said "Timing retard is never going to be NEEDED" and i disgree, not sure why you think i am pretending. I think your deffinition of the word "need" seems to be a little different than mine on this topic. Under your way of thinking you can also so you don't NEED to have oil in your engine for it to run, which is true but it will destroy itself very fast. So yeah, you never NEED to retard ignition timing but if you boost it to a certain level it will start to get detonation and breaking internal engine parts no matter how low your compression is.

M I N I O N - Sinbird wrote:I'm going to again say that retarding timing doesn't rob your horsepower, it allows you to have the same horsepower safely with a little more boost and less fuel consumption.

Yeah, it won't cause a loss of power if you add more boost to make up for it, lol.


- 93 mph in the 1/8 mile
Member of J-Body Of Michigan.

^^^^^ Ok then... you need to pull timing... since every single car on the site that is boosted is running an MSD with boost retard...... You are going from one extreme to the other with the oil thing.. that is just rediculous.
I pull timing on all of my boosted cars. Why are you trying to argue with ME about this?

"You do want to pull timing for safety purposes." - me
"Retarding timing is simply a way do avoid detination" - you

And to me... "needed" means you have to do it. How many people here are actually doing it? I'd say my deffinition of "need" is right on the money.

"Just because you lower your compession ratio does no mean you will never need to retard timing, lol. "
I never said that? So why is it funny?

We are saying the exact same things besids for you saying pulling timing robs horsepower. If you want to take it into the absolute most litteral sense possible, then fine... pulling timing is going to mean less horspower, but nobody that is actually taking the effort to tune the timing curve is going to pull lower numbers on the dyno from it... they are doing it to run more boost and more finely tune the engine.



Cardomain|Myspace

M I N I O N - Sinbird wrote: ^^^^^ Ok then... you need to pull timing... since every single car on the site that is boosted is running an MSD with boost retard...... You are going from one extreme to the other with the oil thing.. that is just rediculous.
I pull timing on all of my boosted cars. Why are you trying to argue with ME about this?

Because you say you never need to pull timing and i disagree, but when i did you said i was only pretending to disagree.......lol. The oil thing is not rediculas at all, there are things you "need" to do to make you motor survive and having oil in it and not letting it constantly detonate are a couple of them.

M I N I O N - Sinbird wrote:And to me... "needed" means you have to do it. How many people here are actually doing it? I'd say my deffinition of "need" is right on the money.

And how many people have blown thier motors due to detonation that could have been prevented by pulling timing?

M I N I O N - Sinbird wrote:"Just because you lower your compession ratio does no mean you will never need to retard timing, lol. "
I never said that? So why is it funny?

You said, and i quote "You run lower compression so you can run higher boost safely. Timing retard is never going to be NEEDED". This was in responce to the question "If you're running a lower compression, retarding timing wouldn't be that necessary because you are less likely to detonate (example: going from 10:1 to 9:1 compression)?".

M I N I O N - Sinbird wrote:We are saying the exact same things besids for you saying pulling timing robs horsepower. If you want to take it into the absolute most litteral sense possible, then fine... pulling timing is going to mean less horspower, but nobody that is actually taking the effort to tune the timing curve is going to pull lower numbers on the dyno from it... they are doing it to run more boost and more finely tune the engine.

I'm glag you finally admit you were wrong.





- 93 mph in the 1/8 mile
Member of J-Body Of Michigan.

^^^^Ok, you stop pulling timing because it ROBS horsepower and I will do it because it allows me to run more boost safely. I'll try your no oil trick too.
I'm really done arguing about it. I would say "agree to dissagree" but you are arguing from the same side.

Quote:

You said, and i quote "You run lower compression so you can run higher boost safely. Timing retard is never going to be NEEDED". This was in responce to the question "If you're running a lower compression, retarding timing wouldn't be that necessary because you are less likely to detonate (example: going from 10:1 to 9:1 compression)?".

Way to cut me off mid-sentance. Plus I said you never NEED to pull timing, not just when compression is dropped. With lowered compression you want to run a more aggressive timing curve out of boost and pull in boost.

"nobody that is actually taking the effort to tune the timing curve is going to pull lower numbers on the dyno from it... they are doing it to run more boost and more finely tune the engine."

"You do want to pull timing for safety purposes."
"Remember that a better tune will allow you to run more boost reliably."
"Every additional pound of pressure in the combustion chamber is going to mean it takes that much less time to fully burn the mixture."
"it is just a wa of more accurately tuning your engine. I'd do it, but thats just me."
"I would go with a programmable ignition system."

Some people on this site swear by not pulling timing. If you really think it is absoultely necessary to run a boosted J-body, then you are VERY wrong.

Quote:

i dont pull timing and I am at 10 psi

Hurry up and pull timing because not pulling timing is OBVISOUSLY just as bad as havin no oil.




Cardomain|Myspace

There is no hope for you...


- 93 mph in the 1/8 mile
Member of J-Body Of Michigan.

I know

lemme go pull some timing so i dont screw up my motor!!!

My car is fine with boost and timing.. when I start having problems I will then pull timing not before hand



LE61T PTE6262 Powered

So me and skillz had a nice talk on AIM.

This is what we agreed upon:
The big confusion wasn't with "need" but rather "never." Timing retard is always wanted, at a certain point it is deffinately needed. The stock J-body runs a very conservative timing curve from the factory that keeps it nowhere near detonation. Add 93 octane to the mix and there is some room to play with. The average guy running low boost is OK keeping it inside these ranges but it is best to put her on the dyno and see where you are. Skillz told me about some cases he had seen where even at low boost the knock sensor triggered some retard from the computer. To that, I will say be safe! Do things the right way. It wont hurt you to set-up your ignition system to pull timing and then find out you are right around the money already. It WILL hurt you if you don't do it and then find out your are on the verge of detonation or beyond. As skillz had said to me (and this is COMPLETELY true) "Optimal horsepower is reached when you are advanced to just BEFORE point of detonation." With boosted cars this is usually retarded further than factor timing.

Long story short... do it. It can't hurt you if you pull it, it can hurt you if you don't.

Hope that is a little better.



Cardomain|Myspace

check out sno performance products, they have a water methanol injection setup that can solve these kind of problems for boost and juice.
you can runb the boost you want without having to retard.