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Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: kmart356 ()
Date: April 11, 2020 11:39AM

The standard distributor can be considered a 2 dimensional device that controls timing with mechanical advance based on RPM and vacuum advance or boost retard (turbo) to alter timing based on load. Here are a few factory advance curves to compare the start RPM and the rate of advance.



Specifically for turbo engines, Dale Manufacturing created the advance/retard unit that added vacuum advance. Still 2D timing but better.The 3D graph with Dale A/R installed on a 150hp turbo distributor is shown below.



My 1st performance timing attempt was a Custom 18* distributor with more aggressive low end mechanical advance with Dale A/R. The 3D graph for that set up demonstrates the advance curve looking like a non-turbo and then boost retard under boost conditions. Driving was much more pleasant prior to boost , was much easier to smoothly accelerate and felt stronger when boost came on for plenty of fun.



After installing methanol-water injection and a Mikuni HSR45 smooth bore carburetor, the quest for improved timing to optimize performance began in earnest. Like distributors, many engine controllers are parameter driven. You input base timing (RPM controlled timing), vacuum advance and boost retard parameters (kPa controlled). This provides very good results but lacks that capability to control timing beyond the RPM vs kPa parameters that are set ie. 2 dimensions.

3D timing: The CB Performance Black Box provided me the capability to directly control all aspects of timing. The capability of manipulating the timing map in table format (and associated data entry effort) results in real 3D timing. In my example, timing is added based on vacuum but not the same amount at all RPMs (displayed as hump). The boost retard timing reduction is also different at specific RPMs for same psi reading. This 3D timing map has been successful for my engine all during 2019.



Following recommendations from 63turbo two new steps towards optimizing performance were taken. 1st was to create a dip in timing at the onset of boost in the peak torque region (it looks sorta like swimming pool). The dip in timing adds load which drives boost up more quickly. 2nd was to add timing above peak torque (4000rpm) which drives power as RPMs increase. As a side note this is consistent with the factory turbo mechanical advance (4000-4500rpm).
The nickname for this timing map is “Stout”.



Driving impressions: “this little guy kicks it when it starts spooling. It felt much more responsive everywhere even 78-79* weather. Wowser !we were drinking methanol like we stole it!!! No knocks to be heard so far.” “Once it goes positive pressure the spool up is way more aggressive and especially above 4000rpm. It feels like a really strong push at higher rpm and the time between 10 -> 14psi is much shorter almost like a snap. It also seems to hold boost better between shifts.”

There is another performance improvement under development… nickname “wild child”. Details to come after testing.grinning smiley

Thanks go to 63turbo, PressurizedPancake, thewolfe, MattNall, toms73novass, for recommendations, feedback and comments that helped plenty along the way.

Ken
'62 Spyder Coupe
Florida


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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: 63turbo ()
Date: April 11, 2020 12:21PM

I've been running a 2D version of "wild child" on my early turbo for quite a while
now, and all I can say is WOW!!! It runs like a naturally aspirated Corvair does while out of boost, but when I stand on it, CRAP!! no fake boost anywhere... really hard acceleration all the way up. 1st gear boost is between 10 and 15psi depending on the rpm that the throttle is snapped open, and second and third gear boost will go over 20psi if I let it. Peak timing is 18 degrees which is plenty safe for 20psi. It has to be experienced to be believed!!

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: playerpage ()
Date: April 11, 2020 02:40PM

How easy is a setup like that to install, and how much does it cost to get it?

____________________________________________

Eric C. Player, Porterville, CA, USA (Seriously! It's the USA out here!)
MEMBER: CORSA National, Central Coast CORSA, South Coast CORSA, Vintage CORSA, Sfba CORSA, and the San Joaquin Valley Corvair Club.
THEN:
1965 Monza 110, Canary Yellow
1965 Corsa 180 Turbo, Red
1966 Monza 110, Purple
1967 Monza 140, Red
1966 500 110, Black; nicknamed "Shadow"
1965 Monza 110, Camaro Yellow; nicknamed "Silver"
NOW:
1966 Corsa 180 Turbo, Blue; nicknamed "Bluvair"

"He cautioned me not to take notes. It would not have helped if I had, as he would start a paragraph with, 'It is therefore obvious. . .'
and go on from there to matters which may have been obvious to him and God but to no one else."
-- Robert A. Heinlein, character of Daniel B. Davis, 'The Door Into Summer.'

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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: 63turbo ()
Date: April 11, 2020 02:53PM

playerpage Wrote:
-------------------------------------------------------
> How easy is a setup like that to install, and how much does it cost to get it?

The Black box is less than 300, and can be used with your distributor. You just have to lock it so it will not advance. kmart356 is one of the experts with these systems and is a great source of info about how to do it. And how to program it!

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: kmart356 ()
Date: April 11, 2020 04:55PM

playerpage Wrote:
-------------------------------------------------------
> How easy is a setup like that to install, and how much does it cost to get it?


CB Performance sells the black box and has sold many to the hot rod VW tuners.
There are at least 5 Corvair guys that have one as far as I know. The Black Box is selling for $199.95. It has on board MAP and wiring is straight forward.
The most complex part is to figure out how to lock your factory distributor ( I did mine ) so that you can feed the black box 0* timing. Some after market distributors can be locked as well. BB accepts mag trigger distributor also so there are some choices.

Send me a PM if you have more questions cool smiley

Ken
'62 Spyder Coupe
Florida


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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: Seth Emerson ()
Date: April 11, 2020 08:31PM

I have the Mag pulse out distributors if you need one. I can supply it with the advance locked out. $145 + shipping

Seth Emerson

Check my new Performance Corvair Web site [www.perfvair.com]

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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: playerpage ()
Date: April 11, 2020 09:43PM

Ken and Seth, I will be in touch with you soon! smiling smiley

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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: pvholgado ()
Date: April 12, 2020 01:10PM

interested-- following topic

"A sign of great intelligence is being able to say 'I don't know'"


1966 Corsa Turbo Coupe current being "refurbished"
Located 25 miles East of Rochester, NY

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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: kmart356 ()
Date: April 14, 2020 02:01PM

This is the 'wild child' beta test version of optimized timing. This is based on the static timing curve from the Custom 18* distributor with a few degrees of timing added above 3800rpm.The solid bold line indicates base timing at neutral manifold pressure here at sea level.

These unique characteristics can not be accomplished with a distributor or parameter based timing... only table driven 3D timing can do this stuff**.
** The max advance region @ high vacuum-low loads is shown in the 3000-3800rpm region.
- Advance is reduced for the same vacuum values at 4000rpm and up to prevent the black box from running out of dwell.
- Advance is increased to provide a strong Idle at 32*
**The swimming pool is created by taking out a few additional degrees in the peak torque RPM range to load the engine and build boost rapidly.
- Timing is added back in at the same psi values for RPM above 3800 to build power. (much like the 150hp turbo distributor advances at 3900 and up)
**The twin dotted lines half way into the boost region indicates where methanol injection starts and no timing is taken out from 4.5-6.5psi. Boost retard starts again after that.

The daytime temps have shot up here recently so testing will have to coincide with cooler mornings so that comparisons will be more valid. The methanol tank will be topped up for sure.thumbs up




Ken
'62 Spyder Coupe
Florida


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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: joelsplace ()
Date: April 14, 2020 03:21PM

- Advance is reduced for the same vacuum values at 4000rpm and up to prevent the black box from running out of dwell.
? What does advance have to do with dwell?

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: kmart356 ()
Date: April 14, 2020 03:52PM

Specifically for the Black Box, the electronic dwell circuit can only provide up to 40* total timing for the 6 cylinder application when rpm is 4000 or higher.
At lower rpm the circuit is ok providing up to 44-45deg total advance. The reference signal for the BB is 0*

Ken
'62 Spyder Coupe
Florida


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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: joelsplace ()
Date: April 14, 2020 03:59PM

That seems odd since dwell is only limited by the time between firing I don't see how it matters when it fires.
I guess you could set the static timing at whatever minimum advance you use and then adjust all the maps by that much. That would give you more head room for advance.
For example - If you set the static timing at 10 degrees and subtracted 10 from all points in your map you would have 50 degrees total advance available instead of 10. Does that work?

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: kmart356 ()
Date: April 14, 2020 04:08PM

That logic sounds valid... but I won’t try it though as I don’t want or need more than 40deg total advance under light loads above 4000rpm
Not doing much cruising at 80mph these days smoking smiley

Ken
'62 Spyder Coupe
Florida


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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: joelsplace ()
Date: April 14, 2020 04:14PM

Some areas around here have 75mph speed limits so...

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: toms73novass ()
Date: April 15, 2020 05:58AM

Ken, great work! love the "wild child" thumbs up

-Tom


63' Monza Spyder Convertable (in process) MY Build Thread
65' Monza MY Build Thread
73' NovaSS 454 Big block (Sold)
86' BMW 325es
98' VW Jetta TDI, for daughter
01' Audi Allroad Stage 3 twin turbo

NFCC
Grand Island, NY

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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: kmart356 ()
Date: May 12, 2020 03:00PM

Continued fine tuning has resulted in this new timing map... "the trench". This concept came about after reviewing some video where I recorded the kPa vs rpm during a few strong boost runs. After seeing the boost vs rpm curve the timing map was fashioned to keep 28*-29* along that same curve. If the rpm is below optimal when hitting boost, the timing falls off into the trench to create load and assist with spooling. This is followed by increased timing when the rpms come up.

This timing is just tickling the Safeguard and feels very responsive and strong. I am creating a blind experiment to test the trench vs wild child to remove any bias I might have going into test drives. smoking smiley



Ken
'62 Spyder Coupe
Florida


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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Date: May 13, 2020 05:21AM

I would think timed accelerations in the same gear across the same RPM band on the same stretch of road back to back on the same day would tell you the story without relying on the ass-o-graph.

Hand stopwatch or video with tach and stopwatch in frame would be your data acquisition, unless you have a Go-Pro w/integrated GPS.

Eagerly awaiting for your results smiling smiley

---------------------------------------------------------------------------------------------
You're unique, just like everyone else...

Johnny B
Central WI

Wife's '68, 3.0L, twin-screw compressor and fuel injected in the works...

Project Pressurized Pancake


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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: DynoDave ()
Date: May 13, 2020 07:42AM

A big thanks Ken! This is one of the most informative posts on Turbo timing I have ever seen!

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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: kmart356 ()
Date: May 13, 2020 09:53AM

DynoDave Wrote:
-------------------------------------------------------
> A big thanks Ken!

My pleasure... the key has been the flexibility of using a fully programmable timing box and as mentioned before, my thanks go to 63turbo, PressurizedPancake, thewolfe, MattNall, toms73novass for recommendations, feedback and comments to steer me straight.

MrPancake - I have a highly calibrated "ass-o-graph" grinning smiley but will use video for data gathering at high frame per second setting (sorta like stopwatch)

Ken
'62 Spyder Coupe
Florida


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Re: Turbo Ignition Timing – Optimizing Performance with 3D Timing
Posted by: DynoDave ()
Date: May 14, 2020 06:39AM

The most accurate way would be to do it on a dyno IMHO

But I am very partial to dyno's as I owned a Dyno manufacturing company
(DTS Dyno's) for 30+ years. lol

I have a project underway with a 180 turbo engine using a Holley Sniper 2V that I am setting up on my engine dyno right now, but it has to be put on hold unfortunately because I just retired and am moving to Az.

Once I get back at it will be doing a 3d map of both fuel and spark. Should be interesting and fun.

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