Fast Idle Install

Erik712m · Post by **Erik712m** » Sun May 10, 2009 3:35 pm

If I want to use it all the time do I need to just bypass the temp shut off? Right now it is on while the engine is cold but shuts off after engine temp is over a 100 DEG.

Trying to reduce stalling during idle. Can't make it up the drive without killing it.

How are you getting it to fluctuate?

Jim LaGuardia · Post by **Jim LaGuardia** » Sun May 10, 2009 4:07 pm

Look at the SDS site to see how the system operates. All EMS computers that I use have constant I.A.C. control open or closed loop if used.

MASSIVE PINZ · Post by **MASSIVE PINZ** » Mon May 11, 2009 9:54 pm

I am generally not pleased with the IAC on aircooled engines. I have tried them with Motec, Haltech, Lynk, Autronic and multiple times with SDS. The unit on my personal car has been disabled for 5 years and was totally un-necessary.

I had lots of issues with inconsistent idle speeds dependent upon air density and temperature more than anything else.. You can add one to the engine fairl easily and SDS will control it, but I don't think you'll be pleased with it.

Erik712m · Post by **Erik712m** » Mon May 11, 2009 10:03 pm

Jake, So far I'm pleased with it. Until the engine warms up than it just shuts off! Herbert and Alan Have one that stay's on all the time making it one hell of an off road easy crusier.

Or there doing something there not telling me? but there idle is unstoppable!

Alan let me drive his pinz while in Florida and it would just crawl over rocks or wood with out pedal with ease. I'm tring to reproduce it. SDS has stated I should be able to do the same the programming is just over my head.

MASSIVE PINZ · Post by **MASSIVE PINZ** » Mon May 11, 2009 10:13 pm

Some of the controllers are variable and they will partially open or close. Others are for cold start only and they shut off and on completely. This is probably what you have.

pinztrek · Post by **pinztrek** » Tue May 12, 2009 5:59 pm

Hello Erik,

As you know from driving my truck, I consider the offroad idle performance to be one of the major wins of our design. This is way more than just map tuning, it's several things being actively managed. I'll share some basics, but ultimately it will boil down to whether your controller has some of the capabilities combined with how well you tune it. For what it's worth, I probably have more time tuning/refining the offroad idle performance than the overall tuning on the 2.5l engine.

This is detail that if you are not interested, just skip to the next article. I know some are interested, so I'll make the long post.

Some definitions:

Idle Air Control (IAC) - typically implies full management of idle via stepper motor or some other variable device.

Fast Idle Control (FAC)- usually a solenoid that just bumps the idle up a bit by allowing a certain amount of air to bypass the throttle plate. Can be thermo-mechanical or solenoid based under ECU control

Some basics:

There are about 5 or so states that we manage IAC:

Cranking- we set the initial idle during cranking to various positions depending on combined engine/air temperature. We also set other cranking parameters (fuel, spark, etc) based on engine warmup state

Warmup fast idle- Engine idle is set higher depending on where the engine is at in it's warmup cycle. Very cold could be as high as 1350. Fully warm it's standard idle. Again, multiple fuel/spark tunings taking place at the same time.

Normal driving- Not idle based on RPM & TPS. Idle Air is off.

Idle- below setpoint- Variable rate increase of idle air depending on how far & how fast it needs to recover. This is far more than the "low/high" settings upper end hal-tech's & the EMS stinger have. We have three different states with separate behaviours (opening rate, etc). Our controller also controls fuel & ignition in this case as well.

Idle- above setpoint- Again, variable rate decrease of idle air depending on gap. This one is two state with different closure rates.

Deceleration to idle- How the IAC behaves in a decel event, when you have taken your foot off the throttle, but are not down to idle control range. EMS & Haltech let you set when idle control resumes, but not how. And no control of rate, bump up of idle, etc.

So how do you apply this to your vehicle? Don't know... depends on the controller. To my knowledge the SDS systems only use solenoid (on/off) type fast idle. To Jake's point, limited usefulness except for very cold.

EMS stingers have a basic IAC approach. Set the target idle, percentages on when it engages, TPS setpoints, etc.

Upper end Haltech's ($1000-1500) have a bit more control over how you manage the idle, but are oriented toward GM type stepper motor controls.

Both of these are better than solenoid, but does not have the granularity or modes of what we've developed for the pinz. And again, we are not just managing air in idle control, but also spark/fuel in different engine conditions. IE: Not just normal map tuning.

So how big of a deal is it? I found significant fine tuning in the rates the IAC was managed was required to avoid oscillation/surging. Not talking about steady state idle, but more idle control under varying loads. I don't see how the other controllers will be able to achieve what we have based on how much time I had to spend with rates & "states".

So you don't want to drive at idle? Remember, if your engine is already stalling/bogging and you try to roll on throttle you first have to catch it up before you can accellerate. I can bog the engine down to almost a stall, then roll on throttle without a blip, burp, or anything. Erik & others saw it in Florida repeatedly.

So Erik, I wish you luck. I can't remember which controller you are using, so you'll have to apply sort out which may apply. The sad reality is that most aftermarket controllers are focused on high HP go-fast applications and do not have some of the features that OEM controller have to have in this situation. Think about it, does your car idle up your driveway?

The good news is that Herbert just put our first commercial install into service. This will provide significant feedback to us on non-hobbiest "get in & drive" performance, which is our target market.

Have fun,

Alan

Erik712m · Post by **Erik712m** » Tue May 12, 2009 9:27 pm

Alan, In short I can't SDS the uses FAC I played around to day and installed the A/C relay but all I can do is manually turn it on and off.

So you don't want to drive at idle? Remember, if your engine is already stalling/bogging and you try to roll on throttle you first have to catch it up before you can accellerate. I can bog the engine down to almost a stall, then roll on throttle without a blip, burp, or anything. Erik & others saw it in Florida repeatedly.

Can't some of that be changed in the Accusump settings? I had some hesitation when I would go from idle to slamming on the gas. they were able to completely remove it by changing the setting in this area of the controller.

Alan, Since I don't have the Idle control I think I' going to keep playing around with the bell crank to to increase my lower end pedal movement. Also found a new after market 42mm ford throttle body with changeable wheels on ebay.

EvanH · Post by **EvanH** » Tue May 12, 2009 9:39 pm

I have not seen either manifold, but I assume Jake's manifold is different than Alan's. As I recall, low RPM torque is particularly sensitive to manifold/runner design. And I understand that there is more than cam profile out there which will also impact the torque curve, all else being equal.

Check out this thread for a bit of discussion:

http://www.physicsforums.com/showthread.php?t=244434

-Evan

MASSIVE PINZ · Post by **MASSIVE PINZ** » Tue May 12, 2009 9:42 pm

The accel fuel does greatly impact low speed performance as well as manifold pressure value manipulation.

The SDS IAC is used only for cold start, thats the only time I have ever found it necessary.

Yes. I am guilty of creating things that go fast, anyone can go slow. That said, my truck could easily climb a 20% grade behind my shop at idle in low/low and respond immediately to any change in throttle position.

One of the primary goals of my system was to broaden the usable power of the Pinz engine and that included creating more mid range power for highway operation. The design and volume of my plenum reflects this and it was done without any loss in down low performance.

Erik712m · Post by **Erik712m** » Tue May 12, 2009 9:54 pm

I have lots of low power and high for that matter. And I have a great 750 Idle. cold start and warm up.

To put it simply all I trying to do is climb a rock smoothly with no jerking or my wife complaining about whip lash. I just thought I could play with it in the in the drive or the mall parking lot behind my house.

Erik712m · Post by **Erik712m** » Tue May 12, 2009 10:02 pm

EvanH wrote:I have not seen either manifold, but I assume Jake's manifold is different than Alan's. As I recall, low RPM torque is particularly sensitive to manifold/runner design. And I understand that there is more than cam profile out there which will also impact the torque curve, all else being equal.

Check out this thread for a bit of discussion:

http://www.physicsforums.com/showthread.php?t=244434

-Evan

Evan, this has nothing to do with what I am trying to achieve. Hard for me to explain. but imagine idling up to a curb and just being able to maintain the same rpm or very slowly increase and just roll over it no over compensating.

pinztrek · Post by **pinztrek** » Tue May 12, 2009 10:46 pm

Erik712m wrote:Hard for me to explain. but imagine idling up to a curb and just being able to maintain the same rpm or very slowly increase and just roll over it no over compensating.

It will be virtually impossible to do this with an "On/Off" fast idle control. Which appears to be all the SDS supports.

OEM IAC uses stepper motors or variable bypass valves that typically give 255 steps of variable air bypassing the throttle plate. Solenoid is just all on or off.

Even the aftermarket controllers which do support true IAC will not fully achieve what I refer to as "Off road cruise control", as they just don't have the granularity of control. remember, I'm not just managing air for idle under load, but also factoring in spark & fuel like an OEM does.

As jake mentioned, accel shot is a major part of "tip in" (coming off idle) response. So if all you do is add air without also adding fuel you go lean, usually with a backfire.

Systems which just implement closed loop idle are setup just to trim air 10-20 rpm, and slowly. And normally do not dink with fuel as part of idle control. Since you are not moving the TPS, most systems do not trigger an accel shot.

You could use the fast idle as an "idle up" if your system had a programmable output. Some controllers have an AC mode, which idles up with fast idle. At that point if you were running closed loop (O2 sensor) the system would add fuel and might help. Won't be smooth, but could make it harder to stall.

I'd find a truck with one of the Hal-tech controllers and see if full IAC gets you closer. I'd not spend the money without driving one, as per their manuals & programming software, they do not have the same level of control as I have, nor do they factor in fuel/spark for idle control.

All that said, it was a huge amount of work getting "off road cruise control" dialed in. I would change one rate change param and break another area of idle under load performance. Many hours of up & down hills, bumps. And one visit by cops at a parking lot where we were driving over curbs & parking lot dividers. We feel the results really pay off, which you saw in FL. (And is on youtube)

Have fun,

Alan

MASSIVE PINZ · Post by **MASSIVE PINZ** » Wed May 13, 2009 6:22 am

Alan is correct. SDS will not support a controller that will perform as you desire.

I think that you can achieve what you are looking for with some manipulation of the throttle actuation as it sounds like you are tipping in from idle more quickly than you need to be.

ka · Post by ka » Wed May 13, 2009 11:05 am

there are youtube flix of efi pinzies in the wild?

pinztrek · Post by **pinztrek** » Wed May 13, 2009 11:20 am

ka wrote:there are youtube flix of efi pinzies in the wild?

http://www.youtube.com/user/pinztrek

I'll get jason to post some of his as well. Lot's of video made of my EFI pinz idling over sharp whoop-de-doos, out of a big mudhole with very steep exits, etc.

Have fun,

Alan