horsepower VS timing??

[BEATAV8]

Imo most dont run enough timing and leave a lot on the table. Most havent even verified their timing is accurate.

I don't see where it's very important if the commanded timing is out by 1 or 2 degrees. The numbers on the screen will just be a little different in the end. One can still get the engine to run where it's supposed to with some vigilance.

This one could probably use some more timing... the transition as boost comes up isn't clean yet, but I have something else to try there. This is one of those cases where more boost probably isn't called for. It's just a TA49 and 31-32psi may be a bit of a stretch.

 

[bison]

Well, I would think most people running their cars faster than stock attempt to get the most power out of their cars before they knock. Kind of need to find out where that limit is and everyone's is different. If you have found a magic way to find that limit without ever getting the engine to begin to knock I would like to know!!!

The way i find out is to not find out and be sure im spraying enough alky and using enough octane in the tank. The engine will take a hell of a lot more than 25psi and 22*. On 93 and alky with 9.3:1 CR it will take 24* on top of 25psi. I see guys questioning how much and they arent anywhere near that. How much alky do they need? More than they would think in most cases.

 

[bison]

I don't see where it's very important if the commanded timing is out by 1 or 2 degrees. The numbers on the screen will just be a little different in the end. One can still get the engine to run where it's supposed to with some vigilance.

This is fine if your only being concerned with that particular engine. I work on a lot of engines and having 2 or more degrees of timing than i think it has is not ok. If i say i ran 24* advance thats what i ran. I dont assume the balancer is ok until i check.

 

[bison]

best quote ever!!!!

That's borderline going into my sig !!

Yeah. People need to just grow some balls and try different things if they want to be really fast. Top fuel was the same way for years and years with timing. One team figured out that they could use a lot more than 40* advance and they picked up huge when they did. They simply said **** it. Were advancing this **** till the engine explodes. They went a lot further than they ever though they would doing it and made a huge jump forward in a short amount of time with something that really cost them nothing. Kind of like those that think TSO and Q16 are running around 30psi

 

[bison]

I don't see where it's very important if the commanded timing is out by 1 or 2 degrees. The numbers on the screen will just be a little different in the end. One can still get the engine to run where it's supposed to with some vigilance.

This one could probably use some more timing... the transition as boost comes up isn't clean yet, but I have something else to try there. This is one of those cases where more boost probably isn't called for. It's just a TA49 and 31-32psi may be a bit of a stretch.

With good fuel and aggressive timing on ramp in you will be amazed at how fast it will come up. They will take a lot of timing on the transition. 31.8:biggrin::biggrin:

 

[BEATAV8]

31.8:biggrin::biggrin:

I figured you would like that

Poor old girl has 165k on the clock and she still likes it hot and heavy...

 

[Razor]

Ive always worked up on boost until the motor did not pickup any more MPH. Lets say 20 degree's timing. Once I found that spot be it 24 psi, 28 psi, 32 psi.. then added timing and watched to see if it made more power. The systematic way has proved to me the best way to tweak.

I have also made the mistake of increasing boost past where it did not make more power and added timing=knock

Perfect example of this is a stock turbo car. You can get the needle on the boost gauge to hit 30 PSI.. doesnt mean your going anywhere with it.

Lastly.. nobody has mentioned this yet. EGT.. If you increase timing you decrease EGT. This also gives you that cushion. Example 18 degree's may run 1700 df and 24 degree's may run 1550 df.

Data is important in making decsions. hth

 

[HighPSI]

I'm running an Accel DFI gen7...which is very easy to verify timing with. My offset is almost 10 degrees Not sure if that means that the stock timing was off that much or what.

No, 10 degrees is what the stock ecm uses too. However far you are away from 10* is how much it was off.

FWIW: When I tune a car on the dyno USING RACE GAS, after I have got the boost where I want it (usually maxxed out ) and dialed in the A/F, I will play with timing. I usually have a good idea where it should be before I start, but every combination is different. I usually add/subtract a degree and see what it gains. I have found that you will get to a point of diminishing returns. For example: 20* is 600hp, 21* is 620hp, 22* is 625, 23* is 627, etc.. Since 99% of the time we don't want to run that close to the "edge", I run the car a couple degrees under max and only give up a few hp. Now if you want to talk about individual cylinder timing that's a whole new subject........

 

[DCVING 6]

subscribing

 

[Razor]

A lot of times you can tell when a turbo goes out of its zone as it really starts to heat up the air.

Example rule of thumb(thanks Cal) is 11df. So every lb of boost is 11. At 20 PSI its 220 df. Bigger turbo's(ie 88mm) maybe be less, smaller turbo's more.. but there is a point where the IAT's start climbing above that ref.. and then you can tell.. time for a bigger hair dryer.

If you understand the 11df you can see why IC are needed. Because if its 220df above ambient.. that can easily be 300+ degree's coming out of the turbo=meltdown if you dont run an IC.

The problem with alcohol inj is that it masks this problem. IE stock turbo running 100 degree's IAT at 24 PSI.

 

[driven87]

On an Optimal Balls to the Wall mid 9 second car what would the "sweet spot" boost wise be for a Precision dual ball bearing 70HPQ turbo? Would it be a tad over 30 and then go from there on the timing if it was your combo? Just looking for idea and throwing possible scenerios out there.

 

[usetaboost]

On an Optimal Balls to the Wall mid 9 second car what would the "sweet spot" boost wise be for a Precision dual ball bearing 70HPQ turbo? Would it be a tad over 30 and then go from there on the timing if it was your combo? Just looking for idea and throwing possible scenerios out there.

Mite get better responses in the turbo forum:smile:

 

[Sam Colalillo]

I have found that you will get to a point of diminishing returns. For example: 20* is 600hp, 21* is 620hp, 22* is 625, 23* is 627, etc.. Since 99% of the time we don't want to run that close to the "edge", I run the car a couple degrees under max and only give up a few hp. Now if you want to talk about individual cylinder timing that's a whole new subject........

this is some very good info above.

Here is a crazy story. I was at the track and watched some pro charged big block guys throw 3* of timing into their program go out and the car ran slower. I couldn't believe they threw 3* at it all at once based up on where they were already performing. I was thinking 3 more on our car would send the heads through the hood and give me a nice underhood pressure wash.

Here is an example of how a three degree window performs at the track on our tsm car.

Timing set at value X the car will run 133 mph
value X + 1 degree = 139 mph on average
value X + 2 degree = 143 mph on average
value X + 2.5 degree = 143 mph on average

anymore and the coolant pressure is rising and the heads are lifting. The car has gone faster than 143 MPH on several occassions. It takes more than just tweeking the baseline timing to make it go faster...........individual cylinder correction, air fuel ratio...........ETC.

Getting help from some one that really knows what they are doing is a huge advantage. I wouldn't be anywhere near where I am at with out Cal's help. Maybe there is a little more left in it somewhere.

 

[driven87]

Sam i beleive you had the same turbo i stated. Any chance you can state what boost you were running at its peak? Thanks

 

[HighPSI]

Thanks for the kind words Sam. Based on the data you have given me, there's more in her :smile:
driven87 (sorry, I'm terrible w/screen names :redface: ) There is no "set boost value" for a given turbo. There are a lot of things that can dictate how much boost is "optimal" for an engine. It's all about airflow.

 

[driven87]

Cal i understand there is no set value. Lets take an example of what some people would be running and lets say that turbo has a set of ported GN1's and a decent size roller cam then can a round about boost number be given? Sam in your example i see 3 degrees gained 10mph if i read that right?

 

[HighPSI]

Cal i understand there is no set value. Lets take an example of what some people would be running and lets say that turbo has a set of ported GN1's and a decent size roller cam then can a round about boost number be given?

If you are running the EXACT same turbo as Sam & Toni (are you one of my customers?), I will say 28-36 psi. Like I said, there are too many variables to get you an exact number.

 

[MGTech30]

That is a funny a*s gif video you have there. LOL

Did that really happen in an episode?

 

[RmvBfrFlght]

That is a funny a*s gif video you have there. LOL

Did that really happen in an episode?

The accident is real. Happened 2 - 3 weeks ago in Ohio. A 19 year old doing over a buck passing an unmarked cruiser (hence the dash cam video). He survived the initial hit. Not sure if he is still a survivor or not. For the full video hit u-tube. There are also still shots of the aftermath on other sites.

RemoveBeforeFlight

 

[driven87]

Cal i bought this turbo off a board member it is the same turbo as Sam had.