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      01-18-2013, 12:46 PM   #23
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      01-18-2013, 01:11 PM   #24
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Quote:
Originally Posted by themyst View Post
Psh I put more miles on my car in 3 months than you did in five years. Your turbos aren't going bad anytime soon.

You're arguing its not safe and I am saying other tunes including yours run a similar boost curve.
That my friend is very true. My car is a garage queen. I only push 16.5 max! The maps and firmware that I am using is the older stuff before the aggressive maps so my boost curve is def a drop different. My boost curve is more linear for sure. Either way I still stand by what I stated running 19psi with stockers is asking for trouble and especially if the car doesn't have the supporting mods.
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      01-18-2013, 02:15 PM   #25
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Quote:
Originally Posted by themyst View Post
Actually the logs do show something, his spool response SUCKS on stock dps.
It really does, but i think it has to do more with rolling into the throttle instead of going right to WOT. here is a better log with improved spool speed going straight to WOT, I dialed the boost down to target 17.9, I hit 18.4psi. I'm still running 11C for fuel economy reasons and I like the exhaust sound with the opened wastegates with a value set at 0 (I know, weird that I'm making a thread like this).
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      01-18-2013, 02:29 PM   #26
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Boosting at 19 PSI at 3500 RPM and boosting at 19 PSI at 7000 RPM are two very different values in the realm of the turbo world and efficiency.

We have to remember 19 psi doesn't tell us anything about how fast the turbo's are actually spinning.

Remember that 19 psi is actually a so called back pressure in the engine.

Here is a basic way of looking at boost pressure:

At low RPM there is only so many revolutions where the engine can use the air given. By no accident as the RPM's increase the ability to feed more air is possible, and more of it and at increasing rate.

Lets say you have a fan blowing into the engine at a set rate of 300 CFM.

Using arbitrary numbers at 3500 RPM you may see 3 PSI.

However, if you increase the engine speed to 7000 RPM, keeping that same CFM you might only see 1 PSI. That is because there is less back pressure as engine RPM increases you can utilize that air.

The same principal is here.

The turbo's arent actually spinning any faster to make 19 PSI at 3500 RPM. In fact they may be spinning less at 19 PSI 3500 RPM then at 14 PSI at 7000 RPM. (I dont actually know I'm not looking at an efficiency graphs, just trying to make a point).

In a real world scenario:

My last car was supercharged.
As RPM's increased so did the speed of the blower.
Under normal circumstances so would the boost pressure.
However, if you altered the intake valve timing for more or less overlap that would change the actual boost pressure the motor was seeing. This overlap or lack there of is a restriction and by no accident you could inflate or deflate this number depending on the restriction.

I hope one of these examples can illustrate that boost pressure is a measure of restriction and not a measure of actual turbine speeds.
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      01-18-2013, 06:28 PM   #27
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Quote:
Originally Posted by kkashanchi View Post
can you post the exact map 6 values you're using?
thanks

also, how many gallons of e85 are y ou mixing with 93 to get e50?
9 gallons of E85, the rest is 93octane with 10%, it's an approximate figure because I haven't tested the E85 in this tank, first time I found this new supplier.

The boost value's are (I have slightly modified AFR values too):

1500 15.4
2000 16.7
3000 17.8
3500 18.5
4000 18.5
4500 17.8
5000 17.4
5500 16.9
6000 14.2
6500 12.2
7000 10.9

I originally started at 19.5psi in the midrange, but I ended up with avg ignition correction value of 1.4. I started to play around and taper the boost in the midrange until the correction value was 0, then dialed back the boost an additional .5psi in the midrange because my car reliably overshoots target.


I dialed back boost, too much wheelspin, even starting in 3rd gear @ 2,500rpm. I reckon i'll have better traction when the temps aren't hovering around 60F.

1500 15.4
2000 16.7
3000 17.3
3500 17.5
4000 17.5
4500 17.3
5000 17.2
5500 16.8
6000 14.2
6500 12.2
7000 10.9


When I run methanol (which I haven't had time to install my replacement pump), I taper to 14.7psi at redline with the additional fueling it brings. I prefer the settings in bold for the time being, I may consider rerunning close to 19psi once it gets warmer and I can get the methanol pump back on.
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      01-18-2013, 08:30 PM   #28
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Quote:
Originally Posted by spool twice View Post
9 gallons of E85, the rest is 93octane with 10%, it's an approximate figure because I haven't tested the E85 in this tank, first time I found this new supplier.

The boost value's are (I have slightly modified AFR values too):

1500 15.4
2000 16.7
3000 17.8
3500 18.5
4000 18.5
4500 17.8
5000 17.4
5500 16.9
6000 14.2
6500 12.2
7000 10.9

I originally started at 19.5psi in the midrange, but I ended up with avg ignition correction value of 1.4. I started to play around and taper the boost in the midrange until the correction value was 0, then dialed back the boost an additional .5psi in the midrange because my car reliably overshoots target.


I dialed back boost, too much wheelspin, even starting in 3rd gear @ 2,500rpm. I reckon i'll have better traction when the temps aren't hovering around 60F.

1500 15.4
2000 16.7
3000 17.3
3500 17.5
4000 17.5
4500 17.3
5000 17.2
5500 16.8
6000 14.2
6500 12.2
7000 10.9


When I run methanol (which I haven't had time to install my replacement pump), I taper to 14.7psi at redline with the additional fueling it brings. I prefer the settings in bold for the time being, I may consider rerunning close to 19psi once it gets warmer and I can get the methanol pump back on.

thank you so much! what is your open loop fueling set at?
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      01-18-2013, 08:32 PM   #29
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Quote:
Originally Posted by spool twice View Post
9 gallons of E85, the rest is 93octane with 10%, it's an approximate figure because I haven't tested the E85 in this tank, first time I found this new supplier.

The boost value's are (I have slightly modified AFR values too):

1500 15.4
2000 16.7
3000 17.8
3500 18.5
4000 18.5
4500 17.8
5000 17.4
5500 16.9
6000 14.2
6500 12.2
7000 10.9

I originally started at 19.5psi in the midrange, but I ended up with avg ignition correction value of 1.4. I started to play around and taper the boost in the midrange until the correction value was 0, then dialed back the boost an additional .5psi in the midrange because my car reliably overshoots target.


I dialed back boost, too much wheelspin, even starting in 3rd gear @ 2,500rpm. I reckon i'll have better traction when the temps aren't hovering around 60F.

1500 15.4
2000 16.7
3000 17.3
3500 17.5
4000 17.5
4500 17.3
5000 17.2
5500 16.8
6000 14.2
6500 12.2
7000 10.9


When I run methanol (which I haven't had time to install my replacement pump), I taper to 14.7psi at redline with the additional fueling it brings. I prefer the settings in bold for the time being, I may consider rerunning close to 19psi once it gets warmer and I can get the methanol pump back on.
To be honest you are probably leaving some power on the table for top end. You could probably run a bit more boost, especially on methanol or run more ignition.
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      01-18-2013, 09:39 PM   #30
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Quote:
Originally Posted by kkashanchi View Post
thank you so much! what is your open loop fueling set at?
Quote:
Originally Posted by Jeff@TopGearSolutions View Post
To be honest you are probably leaving some power on the table for top end. You could probably run a bit more boost, especially on methanol or run more ignition.
I purposely dialed in my high rpm boost the way I did because I get a 2.4 degree timing drop running boost above 13.4psi @ 6,300rpm when temps drop to 60F running just E85/93 octane only, whereas running the same fuel with temps above 80F, I can run as much as 15psi 6,300rpm with no issue's. Can't wait until it warms up again so I can dial in less tapper.

Then again, I don't know why I just don't keep it set at less tapper and just short-shift right before 6,300rpm, it's easier to set the shift light than hooking up the laptop to change boost values

kkashanchi, you can experiement with boost levels up top if your car is happy with it. My AFR value's are +10 from the default G5 ISO values at 3000 and 4000rpm, and +5 @ 2,500 and 4,500rpm.


I'm still below the efficiency range/ max boost per rpm of these small TD-03 below 5,000rpm. Try it at your own risk though.
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      01-18-2013, 09:45 PM   #31
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Quote:
Originally Posted by Jeff@TopGearSolutions View Post
Boosting at 19 PSI at 3500 RPM and boosting at 19 PSI at 7000 RPM are two very different values in the realm of the turbo world and efficiency.

We have to remember 19 psi doesn't tell us anything about how fast the turbo's are actually spinning.

Remember that 19 psi is actually a so called back pressure in the engine.

Here is a basic way of looking at boost pressure:

At low RPM there is only so many revolutions where the engine can use the air given. By no accident as the RPM's increase the ability to feed more air is possible, and more of it and at increasing rate.

Lets say you have a fan blowing into the engine at a set rate of 300 CFM.

Using arbitrary numbers at 3500 RPM you may see 3 PSI.

However, if you increase the engine speed to 7000 RPM, keeping that same CFM you might only see 1 PSI. That is because there is less back pressure as engine RPM increases you can utilize that air.

The same principal is here.

The turbo's arent actually spinning any faster to make 19 PSI at 3500 RPM. In fact they may be spinning less at 19 PSI 3500 RPM then at 14 PSI at 7000 RPM. (I dont actually know I'm not looking at an efficiency graphs, just trying to make a point).

In a real world scenario:

My last car was supercharged.
As RPM's increased so did the speed of the blower.
Under normal circumstances so would the boost pressure.
However, if you altered the intake valve timing for more or less overlap that would change the actual boost pressure the motor was seeing. This overlap or lack there of is a restriction and by no accident you could inflate or deflate this number depending on the restriction.

I hope one of these examples can illustrate that boost pressure is a measure of restriction and not a measure of actual turbine speeds.
If that is the case than please forgive this stupid question but why does adding a catless DP raise boost alil bit but it is reducing back pressure by quite a bit?
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      01-18-2013, 10:35 PM   #32
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Quote:
Originally Posted by Jeff@TopGearSolutions View Post
To be honest you are probably leaving some power on the table for top end. You could probably run a bit more boost, especially on methanol or run more ignition.
Back in our day, we were running Procede rev2's with very little taper. IMO, boost north of 6500 is irrelevant, you could make it 8 psi for safety's sake since we should be shifting well short of that on stock turbos.

Now that my flatline is fixed, I can shift at optimal points... it's a great feeling.
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      01-19-2013, 12:17 PM   #33
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Quote:
Originally Posted by Jeff@TopGearSolutions View Post
Boosting at 19 PSI at 3500 RPM and boosting at 19 PSI at 7000 RPM are two very different values in the realm of the turbo world and efficiency.

We have to remember 19 psi doesn't tell us anything about how fast the turbo's are actually spinning.

Remember that 19 psi is actually a so called back pressure in the engine.

Here is a basic way of looking at boost pressure:

At low RPM there is only so many revolutions where the engine can use the air given. By no accident as the RPM's increase the ability to feed more air is possible, and more of it and at increasing rate.

Lets say you have a fan blowing into the engine at a set rate of 300 CFM.

Using arbitrary numbers at 3500 RPM you may see 3 PSI.

However, if you increase the engine speed to 7000 RPM, keeping that same CFM you might only see 1 PSI. That is because there is less back pressure as engine RPM increases you can utilize that air.

The same principal is here.

The turbo's arent actually spinning any faster to make 19 PSI at 3500 RPM. In fact they may be spinning less at 19 PSI 3500 RPM then at 14 PSI at 7000 RPM. (I dont actually know I'm not looking at an efficiency graphs, just trying to make a point).

In a real world scenario:

My last car was supercharged.
As RPM's increased so did the speed of the blower.
Under normal circumstances so would the boost pressure.
However, if you altered the intake valve timing for more or less overlap that would change the actual boost pressure the motor was seeing. This overlap or lack there of is a restriction and by no accident you could inflate or deflate this number depending on the restriction.

I hope one of these examples can illustrate that boost pressure is a measure of restriction and not a measure of actual turbine speeds.
+1

Same can be said with full throttle at XXXX rpm in 2nd gear versus full throttle and the same XXXX rpm in 5th gear. The loads on the engine are completely different because of the gears and the speed of the vehicle, so therefore the exhaust pressure to spool the turbo will be very different as well.
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      01-19-2013, 12:56 PM   #34
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Quote:
Originally Posted by cn555ic View Post
That my friend is very true. My car is a garage queen. I only push 16.5 max! The maps and firmware that I am using is the older stuff before the aggressive maps so my boost curve is def a drop different. My boost curve is more linear for sure. Either way I still stand by what I stated running 19psi with stockers is asking for trouble and especially if the car doesn't have the supporting mods.
16.5 ?

arent you running meth? ethanol?

leaving so much power on the table. i mean in the garage?
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      01-19-2013, 12:59 PM   #35
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Quote:
Originally Posted by hemi to e90 View Post
16.5 ?

arent you running meth? ethanol?

leaving so much power on the table. i mean in the garage?
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      01-19-2013, 02:47 PM   #36
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OP, don't mind the banter. I push the shit out of my stock turbo's because I have a single upgrade in my future. I'm running 100% e85 and 100% meth and target boost at 20psi and hit 21 as I spool up. Almost 75k on the same set of turbo's. I think it's luck of the draw a lot of times, so run'um hard and have fun. Just remember, if you play, eventually you pay.
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      01-19-2013, 03:12 PM   #37
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Quote:
Originally Posted by hemi to e90 View Post
16.5 ?

arent you running meth? ethanol?

leaving so much power on the table. i mean in the garage?
lol
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      01-19-2013, 03:13 PM   #38
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And one for you too

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      01-19-2013, 07:12 PM   #39
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lol
i jest.

you gonna be around next week? im having issues with the lighting coding on the car, and i wanna try out "eco mode"
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      01-19-2013, 10:04 PM   #40
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How do you guys get the boost to taper as you approach redline. Are you playing with Wastegate DC and changing the numbers at higher boost to increase the taper. I'm getting 13psi at redline and want to limit that.
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      01-20-2013, 10:17 AM   #41
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Quote:
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How do you guys get the boost to taper as you approach redline. Are you playing with Wastegate DC and changing the numbers at higher boost to increase the taper. I'm getting 13psi at redline and want to limit that.
It depends on the tune, I don't have the ability to mess with Wastegate DC without affecting the wastegate default position and therefore, WG rattle issue's may creep up.

I just set mine to target X boost and let the JB4 take care of the rest and target redline boost within +/- .2psi

I cranked up boost from:

1500 15.4
2000 16.7
3000 17.3
3500 17.5
4000 17.5
4500 17.3
5000 17.2
5500 16.8
6000 14.2
6500 12.2
7000 10.9

to

1500 15.4
2000 16.7
3000 17.3
3500 17.8
4000 17.8
4500 17.5
5000 17.2
5500 16.9
6000 15.6
6500 13.7
7000 10.9

so far so good, i upshift at 6300rpm though. I'll probably keep these settings, the car seems happy with it, other than having the sensation of some wheelspin once the boost cranks up at 3000rpm in 3rd gear, but that will bound to be better once the weather gets warmer
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      01-20-2013, 10:18 AM   #42
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Quote:
Originally Posted by Wedge1967 View Post
OP, don't mind the banter. I push the shit out of my stock turbo's because I have a single upgrade in my future. I'm running 100% e85 and 100% meth and target boost at 20psi and hit 21 as I spool up. Almost 75k on the same set of turbo's. I think it's luck of the draw a lot of times, so run'um hard and have fun. Just remember, if you play, eventually you pay.
I thought about over-driving them in the midrange a little past max boost/efficiency range, but I'll wait until I get downpipes hopefully will be in the next 2 weeks
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      01-20-2013, 12:54 PM   #43
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Quote:
Originally Posted by spool twice View Post
I purposely dialed in my high rpm boost the way I did because I get a 2.4 degree timing drop running boost above 13.4psi @ 6,300rpm when temps drop to 60F running just E85/93 octane only, whereas running the same fuel with temps above 80F, I can run as much as 15psi 6,300rpm with no issue's. Can't wait until it warms up again so I can dial in less tapper.

Then again, I don't know why I just don't keep it set at less tapper and just short-shift right before 6,300rpm, it's easier to set the shift light than hooking up the laptop to change boost values

kkashanchi, you can experiement with boost levels up top if your car is happy with it. My AFR value's are +10 from the default G5 ISO values at 3000 and 4000rpm, and +5 @ 2,500 and 4,500rpm.


I'm still below the efficiency range/ max boost per rpm of these small TD-03 below 5,000rpm. Try it at your own risk though.
Fair enough. You sound like you got a good head on your shoulders for tuning.

Quote:
Originally Posted by Lifted07Duramax View Post
If that is the case than please forgive this stupid question but why does adding a catless DP raise boost alil bit but it is reducing back pressure by quite a bit?
Adding catless DP alone does not raise boost, in fact it lowers it, but when you get catless downpipes, the tuning options within raise boost.

In fact if you just got downpipes on a stock vehicle you will notice lower wastegate duty cycles and lower boost, however, you would have about the same power, it would just run more efficiently.

The stock tune is based on load. So it does not target higher boost if the efficiency is improved. The intention of this design is to have a car that makes "300 HP" in arizona heat, the mountain of Colorado, or the so called normal weather of NYC. Although in practice they dont actually make the same power, the point is the intention is to target load and use the boost to persuade that power up or down depending on efficiency. If you can increase efficiency either with colder air, higher octane, improved exhaust flow or any other means the stock tune will lower boost because it can make the same power with LESS boost because of the improved efficiency.
Maybe someone else can clear up load targeting vs boost targeting in a simpler way. I probably confused everyone haha.

Also don't confuse exhaust back pressure with engine back pressure in which case the latter has to do with the heads and valve timing for a good portion of that back pressure.

Quote:
Originally Posted by themyst View Post
Back in our day, we were running Procede rev2's with very little taper. IMO, boost north of 6500 is irrelevant, you could make it 8 psi for safety's sake since we should be shifting well short of that on stock turbos.

Now that my flatline is fixed, I can shift at optimal points... it's a great feeling.
This is true, I rarely drove past 6500 RPM. I remember seeing a good 15.5 PSI at 6000 though with 12 degrees of timing on methanol.

Quote:
Originally Posted by Enron Exec View Post
+1

Same can be said with full throttle at XXXX rpm in 2nd gear versus full throttle and the same XXXX rpm in 5th gear. The loads on the engine are completely different because of the gears and the speed of the vehicle, so therefore the exhaust pressure to spool the turbo will be very different as well.
Good point.

Much easier to ramp up the boost in 3rd of 4th gear compared to 1st and 2nd.

Last edited by Jeff@TopGearSolutions; 01-20-2013 at 01:01 PM.
Jeff@TopGearSolutions is offline   United_States
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