My example was for the track, but the same applies for a daily street-driven truck.

 

First, much better thread topic BC! Maybe with a few more posts under my belt I can get the hang of a properly named thread! LOL

jephs, your statement/questions doesn't seem to take into account what thunder is preaching. Ky...(hehehe I said KY) is the simplest but shortest explanation. In short, using the correction table, I am doing what you are suggesting in bold in your statement. The problem is that particular timing is with the restraints of heat included. You are leaving power on the table in the launch. Inconsistency will be taken care of with a "TUNED" correction table. I hope no one is just suggesting to throw any spark in this table anywhere. You are thinking this correction table only as retarding. Add timing before 98*IAT. Take away timing at 113*IAT and up. Or address it however works best for your application and location.

If it's too hot, then fine you aren't awarded the max timing in the table. If it's colder, then you get bonus timing....no tune changes.

What's so inconsistent about using it. Having a spark table tuned to run with what your high IAT is? What fun is that? This way in my tune, I am attempting to run the best timing to net me the best times...street mostly, but track as well. I am just tryng to take advantage of cooler temps down low when I have them.

 

Ok I am only going to speak for MagnaCharger on this one. On a Magna Charged vehicle please do not attempt to do any IAT timing for any reason or engine damage could occur The IAT sensor on a Magna Charger is only there for safety purposes and SHOULD NOT be used for any performance tuning, the sensor is in the manifold and is very subject to reading radiant heat off the manifold and not of the true IAT itself and the sample rate and update rate is slower than most other sensors in the data stream so using it for any other reason other than it was designed for is not suggested and could cause engine damage due to detonation . Many hours of testing has proven that at 160 IAT the fuel starts to dissipate and the engine starts to go lean so keeping your IAT's under 160 is a big + but on A magna Charged vehicle changing the timing at 105 degrees and 125 degrees will net nothing in the way of HP our chassis dyno and engine dyno has proven this time after time. Using IAT timing in a Non supercharged application can net great results if the IAT sensor is in the MAF and proper tuning is applied. Like I said I am speaking for Magna Charged vehicles only and no other.

 

After the way the last posting went I considered keeping out of this one, but I'll add a bit to it. Somehow there is a misconception that there is timing being added when the blower is warm. From 104 degrees and up there is timing pulled and not added. For those that have already seen some of my IAT work you can see that it goes right along with what Crash Dummy posted that adding timing at 105 degreeds isn't going to gain anything. This isn't just a saftey reason, this is because the Radix being the heat pump that it is you'll lose power if you don't start pulling timing around that point. The point where adding timing comes in is around 86 degrees of IAT and colder. If you run logs on a Radix truck you'll find that you are only under 100 degrees for about the first 100 feet. The question of why not just put the timing where you want it in the first place is that you aren't going to be able to run the same amount of timing at say 80 degrees of intake temperature as you are 120 which if you're running a smaller pulley is around mid track. This is the day of high tech tuning. Trying to tune an engine that runs such a wide basis of air temperature with one specific number sounds like something you'd do with an older vehicle with a distributor or something that is tuned only on a dyno where you are only wide open for a few seconds. Tuning a radix to run it's best numbers pretty much commands that you have to compensate for the impressive amounts of heat that the Radix makes from start to finish. I also pull timing a bit sooner in the ECT table than the Radix tune comes with. I've found that if you are running a fairly agressive base timing table that you will run into some spark knock conditions (sometimes audible and yet not picked up by the sensors) at around 190+ degrees. I add timing for the engine if it is cooler than 167 degrees since we all know that this is the reason we spend so much time trying to cool the engine in the staging lanes and pits. A cooler engine will take another degree or so of timing without knock. The other thing this takes care of is that it allows the customer to run the stock thermostat in colder temperatures if he'd like and the pcm will pull a degree of timing out verses when he's running the 160 stat and not have to change the programming of the pcm. With today's technology I don't see why there would be a reason to not take advantage of the extra tables.

 

I think the waters have become a bit muddy'd here so let me throw my 2 cents in and mix it up a litle more:

On a TRACK ONLY tune I would tune WITHOUT the IAT's (zeroing the IAT table), using only the high/low octane tables for consistency....this is THE ONLY WAY you can guarantee consistency in your tune and can attribute changes in et/mph to temps, trach condition, mods, etc. "taking advantage" of the extra tables will net you nothing more than having one more variable in your setup....and we all know that the best drag racers keep it simple and efficient. I think logging IAT's when drag racing is agreat idea though...it'll help you nail down your timing tables so that you won't have to rely on a timing table adjustment

On a street tune I would 100% use the IAT table, it's there for protection of the engine and should be used as such....but ONLY as such. I think that trying to use the IAT tables any other way is asking for trouble....the sensor doesn't update fast enough to be of REAL use in performance tuning and relying on it is just askig for problems

 

I take it you have not been to the track many times fast vehicles. lol. Its no were near simple and there is many variables in tunes from day to day, track to track and temp to temp. No sense arguing with people tuning double didigit ET vehicles...............I guess.

 

I beg to differ there son...I've owned a few vehicles 11-second vehicles (one of them front-wheel drive and 4-cylinder), yes that IS double digits but if you don't want to argue with people like that because we don't know what we're talking about then I guess you just called quite a few people on here stupid (parish8, TurboBerserker, BlownChevy, moregrip). I think you should choose your words a little more carefully next time.

As for not knowing my ****...hmm, let's see. OK, go ahead and tune with the IAT table and see where it gets you, the IAT sensor is about as accurate as the stock narrowband 02 sensors and we ALL know how accurate those are right . I'd rather not rely on a sensor that has ****-poor resolution and refresh rate to control timing in my engine....but if you'd like to, please feel free. THE only way you'll get consistant results AT THE TRACK is to run a static timing table and not let something like the IAT table add/subtract timing. tune it once and correct for baro/altitude/temp after the run (my game was bracket racing....dial in an 11.03 and run 11.03 - 11.07 ALL NIGHT LONG). If all you're after is to run as fast as you can every time then go ahead and tune your way...if you want consistency then listen to the guys on here that know what they're talking about

And remember...it's ALOT easier to run 10's in an S-10 than it is in a 5600lb full-size.....

 

Amen to that

Good info in here fellas, interesting points.

 

exactly

https://www.performancetrucks.net/fo...12#post3372812

 

He can argue with himself if he wants....I talk to myself