Tuning on AV Gas (9.20@148 so far)
08-23-2015, 02:07 PM
#1
Tuning on AV Gas (9.20@148 so far) So the car is a 79 Malibu wagon.
408, 317's (light porting), pro flow, tick cam.
Car/driver weigh 3700. TH400 3.25 gears and Neal Chance converter.
Turbo is S480 96/1.32
Tuning with HP Tuners
Owner insisted on the AV gas, so proceeding with caution.
Fuel is rich at 10.8:1. Started at 14 degrees timing.
Snuck up on boost and are at 19 psi currently. Ok, he got impatient and turned the ****.....
Last night just worked on getting the car to leave. 2 step and foot brake.
9.30@147 with a 1.38 60 ft.
I worked on the timing on the 2 step because I was seeing a few degrees of KR right when he left the line. Actually helped it make 10 psi while staged.
This turbo spools slow. Doesn't make full boost until the top of first gear.
He wants an 8...not sure we can get there on this fuel. But so far other than the KR I saw on the 2 step, the logs are clean.
Ron
408, 317's (light porting), pro flow, tick cam.
Car/driver weigh 3700. TH400 3.25 gears and Neal Chance converter.
Turbo is S480 96/1.32
Tuning with HP Tuners
Owner insisted on the AV gas, so proceeding with caution.
Fuel is rich at 10.8:1. Started at 14 degrees timing.
Snuck up on boost and are at 19 psi currently. Ok, he got impatient and turned the ****.....
Last night just worked on getting the car to leave. 2 step and foot brake.
9.30@147 with a 1.38 60 ft.
I worked on the timing on the 2 step because I was seeing a few degrees of KR right when he left the line. Actually helped it make 10 psi while staged.
This turbo spools slow. Doesn't make full boost until the top of first gear.
He wants an 8...not sure we can get there on this fuel. But so far other than the KR I saw on the 2 step, the logs are clean.
Ron
Last edited by RonSSNova; 08-31-2015 at 07:56 PM.
08-23-2015, 03:08 PM
#3
Ron, something I ran across:
Key points:
-100LL is not 100 octane as we rate it for pump gas (R+M/2). It is actually ~96 octane by that measure.
-Quality and consistency is better than pump
-Shelf life is better than pump.
-Cheaper because you are not paying Road Taxes. Legally it's like running red dye... no no on the street.
-Lower Specific gravity than pump (density) means you actually run leaner with the same jetting.
-Important one here! Lower flame speed than race gas. 100LL is designed for 3500RPM operation. If you run consistently higher than that you will be spitting unburnt fuel out the pipe. Most pre-run or play cars don't spend too much time over 3500RPM
Key points:
-100LL is not 100 octane as we rate it for pump gas (R+M/2). It is actually ~96 octane by that measure.
-Quality and consistency is better than pump
-Shelf life is better than pump.
-Cheaper because you are not paying Road Taxes. Legally it's like running red dye... no no on the street.
-Lower Specific gravity than pump (density) means you actually run leaner with the same jetting.
-Important one here! Lower flame speed than race gas. 100LL is designed for 3500RPM operation. If you run consistently higher than that you will be spitting unburnt fuel out the pipe. Most pre-run or play cars don't spend too much time over 3500RPM
08-23-2015, 03:31 PM
#4
I got 100LL free back when I worked in aviation so I ran it for years in my stuff. Avgas burns slow and always needed alot more timing in my cars. Usually 8-10* more timing than my pump gas tunes to run "ok" (na stuff)
What compression is the motor? How do the plugs look now? It is only 96 octane, I wouldn't get too crazy with it. I bet it picks up big with another 2-3*. Just need to watch the plugs and go slow.
What compression is the motor? How do the plugs look now? It is only 96 octane, I wouldn't get too crazy with it. I bet it picks up big with another 2-3*. Just need to watch the plugs and go slow.
08-23-2015, 04:08 PM
#5
It's 9.5:1
And, it has TR6 plugs in it that are coming out and being replaced with R5724-8. Same plugs I'm running in my 5.3.
So being honest, I haven't looked at the plugs yet.
I moved the timing from 14 to 15.5. It picked up 3 mph.
But after that just worked on the 2 step stuff.
I have an additive in mind that we just used on the dyno in a Hellcat we tuned. It eliminated all KR and allowed us to add timing to the tune of 40 hp.
Aces IV
It's the blue 100LL. There is no green any more, and the red is really low octane
I'll keep you posted.
And, it has TR6 plugs in it that are coming out and being replaced with R5724-8. Same plugs I'm running in my 5.3.
So being honest, I haven't looked at the plugs yet.
I moved the timing from 14 to 15.5. It picked up 3 mph.
But after that just worked on the 2 step stuff.
I have an additive in mind that we just used on the dyno in a Hellcat we tuned. It eliminated all KR and allowed us to add timing to the tune of 40 hp.
Aces IV
It's the blue 100LL. There is no green any more, and the red is really low octane
I'll keep you posted.
08-23-2015, 08:15 PM
#6
TECH Resident
So do you guys feel that there is power being left on the table due to the AV gas' slow flame travel? Or do you think the timing adjustments make up for it? I need a whisper more power and currently run AV gas.
As always Ron, I look forward to seeing where this tuning adventure goes!
Lon
As always Ron, I look forward to seeing where this tuning adventure goes!
Lon
08-23-2015, 09:59 PM
#7
How long have you been running AvGas Lon?
Get any life at all out of your O2 sensor?
I've read a fair amount about using and as always, there are two sides to the story. Although the "yea's" provided the best hard data.
When I tuned my other buddies car on 110 race fuel, I stopped at 16 degree timing because we met our goal. And didn't get caught.....
But it was also a stock bottom end straight from the boneyard.
Get any life at all out of your O2 sensor?
I've read a fair amount about using and as always, there are two sides to the story. Although the "yea's" provided the best hard data.
When I tuned my other buddies car on 110 race fuel, I stopped at 16 degree timing because we met our goal. And didn't get caught.....
But it was also a stock bottom end straight from the boneyard.
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08-23-2015, 10:41 PM
#8
It's 9.5:1
And, it has TR6 plugs in it that are coming out and being replaced with R5724-8. Same plugs I'm running in my 5.3.
So being honest, I haven't looked at the plugs yet.
I moved the timing from 14 to 15.5. It picked up 3 mph.
But after that just worked on the 2 step stuff.
I have an additive in mind that we just used on the dyno in a Hellcat we tuned. It eliminated all KR and allowed us to add timing to the tune of 40 hp.
Aces IV
It's the blue 100LL. There is no green any more, and the red is really low octane
I'll keep you posted.
And, it has TR6 plugs in it that are coming out and being replaced with R5724-8. Same plugs I'm running in my 5.3.
So being honest, I haven't looked at the plugs yet.
I moved the timing from 14 to 15.5. It picked up 3 mph.
But after that just worked on the 2 step stuff.
I have an additive in mind that we just used on the dyno in a Hellcat we tuned. It eliminated all KR and allowed us to add timing to the tune of 40 hp.
Aces IV
It's the blue 100LL. There is no green any more, and the red is really low octane
I'll keep you posted.
If it went from 144 to 147 with 1.5* at the same boost level, that's a huge gain! Get him to toss some meth/water inj on there and see what another 1.5* will do.
Last edited by Forcefed86; 08-24-2015 at 08:57 PM.
08-24-2015, 01:41 AM
#9
So when he first gets on the two step timing is 21 degrees. As it builds boost and the cylinder airmass increases, the timing drops to 13. It makes 10 psi there.
Once he pulls his foot off the brake and rpm builds it goes to the 15 degrees final timing.
Very much the same as my car. I hit full boost in .6-.7 seconds. His takes 1.5 seconds.
He has 2.5" hot side pipe, ugly merge, one poorly placed WG.
Mine has 2.25" hot side, individual to the turbo and two properly placed WG.
Not to mention 87/1.10 vs 96/1.32 turbines.
It works for him. Doesn't try to rip the tires off when it hits boost like mine does.....
Once he pulls his foot off the brake and rpm builds it goes to the 15 degrees final timing.
Very much the same as my car. I hit full boost in .6-.7 seconds. His takes 1.5 seconds.
He has 2.5" hot side pipe, ugly merge, one poorly placed WG.
Mine has 2.25" hot side, individual to the turbo and two properly placed WG.
Not to mention 87/1.10 vs 96/1.32 turbines.
It works for him. Doesn't try to rip the tires off when it hits boost like mine does.....
08-24-2015, 06:02 PM
#10
There have been many threads on the web and as a general rule people agree that you are leaving quite a bit on the table.... Octane is lower then what people think it is, it's designed for lower RPM range and for lower HP (compared to car's).
Many agree that it's an option... Just not a good one.... Far better to go with E85 or just regular race gas.
Many agree that it's an option... Just not a good one.... Far better to go with E85 or just regular race gas.
So do you guys feel that there is power being left on the table due to the AV gas' slow flame travel? Or do you think the timing adjustments make up for it? I need a whisper more power and currently run AV gas.
As always Ron, I look forward to seeing where this tuning adventure goes!
Lon
As always Ron, I look forward to seeing where this tuning adventure goes!
Lon
08-24-2015, 08:50 PM
#11
TECH Resident
How long have you been running AvGas Lon?
Get any life at all out of your O2 sensor?
I've read a fair amount about using and as always, there are two sides to the story. Although the "yea's" provided the best hard data.
When I tuned my other buddies car on 110 race fuel, I stopped at 16 degree timing because we met our goal. And didn't get caught.....
But it was also a stock bottom end straight from the boneyard.
Get any life at all out of your O2 sensor?
I've read a fair amount about using and as always, there are two sides to the story. Although the "yea's" provided the best hard data.
When I tuned my other buddies car on 110 race fuel, I stopped at 16 degree timing because we met our goal. And didn't get caught.....
But it was also a stock bottom end straight from the boneyard.
No O2 sensor on this POS Ron, lol. It's NA and tuned via time slips. FI is in the future. Time to try race fuel and some timing changes.
Thanks for the input guys!
Lon
08-29-2015, 08:48 PM
#13
TECH Resident
Did you get a chance to pull a plug Ron? Was that a strong 1 mph gain? 60's on each run? Any changes in launch strategy between runs? I'm still very curious how this will play out on the timing end of things.
Lon
Lon
08-29-2015, 11:23 PM
#14
He launched the same every run. But 60 ft was best his last pass, 1.37, same as last week.
I added 1 degree of timing. It maybe picked up .3 mph. But that's not reliable data.
What did help was leaning the fuel. I used my AFX which I trust and it showed 10.5:1 most of the curve. Fixed that in the VE and it liked it.
On that 9.20 run, ECT was 201, and it pulled my added degree back out. ECT timing adder table.
I'll need to mess further with the timing.
So, stock TH400 with a trans go shift kit. The 1-2 shift was good to start the night, and by the end was a barely discernible lump. It's failing.
And it's running to hot.
And seeing a little blow by. Valve cover vents not connected.
But, I bet we run it again next Friday.....
I added 1 degree of timing. It maybe picked up .3 mph. But that's not reliable data.
What did help was leaning the fuel. I used my AFX which I trust and it showed 10.5:1 most of the curve. Fixed that in the VE and it liked it.
On that 9.20 run, ECT was 201, and it pulled my added degree back out. ECT timing adder table.
I'll need to mess further with the timing.
So, stock TH400 with a trans go shift kit. The 1-2 shift was good to start the night, and by the end was a barely discernible lump. It's failing.
And it's running to hot.
And seeing a little blow by. Valve cover vents not connected.
But, I bet we run it again next Friday.....
08-30-2015, 09:06 PM
#15
TECH Resident
So, stock TH400 with a trans go shift kit. The 1-2 shift was good to start the night, and by the end was a barely discernible lump. It's failing.
And it's running to hot.
And seeing a little blow by. Valve cover vents not connected.
But, I bet we run it again next Friday.....
148 while it barfs it's guts or the trans! Sounds like a good time, hahaha!
Lon