well since i dont want to reprogram the PCM everytime I spray... i was thinking of of this...

making a system that will allow me to change the IAT temp ...

Cut the IAT Sensor Line...

then run the end off the sensor it to a double throw toggle switch...

one position will run a wire that will have a resistor inline, to give a specific Temp, then I can modify that section of the IAT Table in Edit to retard timing.

the other positon will run a wire with no resistor so the IAT can operate normally...

and then both lines will run back to the original IAT Sensor wire leading back to the PCM...

anyone see any problems with this ?

 

only the fact that you havent given me a price for it yet! I thought these of something similar, but not that skilled electonically. Will be a customer if you make it work!

 

just an idea i have come up with... u have to have edit in order to make it work to its full potential. technically u could force the temp up to the max without changes to the pcm... but u will only get 2 degrees of retard from 80-85 kpa and 3 from 90-100... in the IAT table at 90c

but in the PE vs Temp table at 90c u are getting 0 fuel enrichment... which means u will run leaner through the injectors...

assuming most cars run between ... 0c (32F) to 40c(104F) ur enrichment varies from .2273 to .0640 in the PE vs Temp Table

If it works i can tell everyone how to do it with what resistors etc... if it works the post before already has a basic outline of what needs to be done.

at the most cost would be 10-15 bucks i would guess... just wire/connectors/resistors/toggle switch

all of this info is based on my 2000 Edit file... FYI, yours maybe different depending on year and type of veh etc.

 

PE vs Temp is coolant temp, not IAT temp. I have been running a similiar setup to what you are talking about for quite some time. I have dyno tested it and it works great. It does not have an effect on fueling.

All I spent was ~$7 for a circuit switching relay and a small pack of resistors.

 

in the GTP world, they get a rheostat(adjustable resisitor), and mod the IAT tables, so they can make a timing adjust, in the car,

what you could do is setup a relay to trigger, when your relay for your nitrous selenoids trigger and it would complete the circuit and pull timing automatically, when you spray how about that for an idea hehe

 

I've installed the setup you describe and it works great.I a 1000ohm resister (think it's 120 or 140 degree's)and set the temp retard to the desired timing retard.

 

I was just talking with Mystic the other day about doing a veriation of this. I wish I would have thought of you.

Buy the way thanks again for helping with Aarons car at grudge. Now if anyone can figure out how to solve the issue with is launching right into 2nd when he stalls it up. If you got some Ideas maybe you can shoot them over to my Email address or pm me. http://www.ls1tuning.com/iboard/index.php?showtopic=476

How is the beast comming?

Thanks again,
Mike Hall

 

sweet if it doesnt have an effect fueling all is well then

Beast should be ready this week for some spray ( at least freeway runs )... .024 jets for 175 shot

 

what are the resistor ratings for each timing retard amount?


ie: xxxxK for xxx degrees..

 

thats a great idea, but why not just setup the maf to kick the timing down based on gms/cyl and spray through the maf? no switches..

 

I have my IAT switching relay wired to my activation switch so there is no additional switches to be seen.

 

there is a aftermarket part made just for that and I forget which place sold it maybe t byrne or thunder racing just shop around.

 

becuase dry shots suck *** hehe

 

I am pretty sure Cartek does this, go to their website and look under their tips, it describes this exact same thing, and they say it works well even with small shots.....I just went ahead and got the timing tuner (yesterday).

 

riiight monkeyboy.. we'll see about that when the lil ol iron motor out does your producto de canada..

 

Wow, how informative this one became.
Vents-some of us Producto de Canada are running DP kits. So, off to Cartek page, and pm a few ppl!

Charlie.

 

Thats a good idea except T/A Medic has a direct port setup

 

Isn't that what the NEW NOS GMAF was designed for?

 

I tried the setup you are talking about in several ways. I first used a potentiometer and my LS1 scanmaster to just dial in the TEMP I wanted while reading it on the Scanmaster. I saw an average of 2-3 degrees of retard. Not really what I wanted. We then tried to program the timing retard that was associated with the IAT. Didnt have any real luck in that area. It seemed we could program it but when testsed it would still only give us the factory timing retard. In other words we could never get it to give us more than 2-3 degrees of retard. So that when we went after the MAF vs RPM tables and that worked out much better.

Forgive me if my terminology is off a bit since I dont own LS1edit. Jeremy at Fasterproms.com does all my tuning. But basically You have to datalog (using EFI live or something similiar) what your MAF flow rates are VS rpm are under normal WOT and plot them. Then in the areas above that flow rate for that specific RPM (what you would see with a dry shot) you can begin to program whatever value you want at every rpm. The only thing is you have to allow for enough "room" in your NA table so you dont accidentally get into the "nitrous settings" on a very cold day. You wont need to retard timing for the first 50-75 shot anyways so you can leave that room there. And it doesnt have a set value across the board. You can look at your nitrous dyno graph and plot the timing you want at various RPM. Because that will be very different from what you want NA. So if your bascally just trying to use the IAT method you will just be pulling a chunk of timing out across your NA timing curve. Which of course is not ideal for nitrous. If you run a single stage BIG hit coming on at 3000 rpm you would want significant timing retard starting at 3000 rpm and you can increase that timing slightly as the peak TQ tapers off with rpm. If your running a dual stage like me you can have it kick back timing at 3000...begin to increase it as it tapers off and then when the second stage comes on at 4800 you can kick the the timing down again exactly when the second stage activates. So obviosly doing it this way can provide an excllent tune. It will also allow you to run around town on your best NA tune..same computer, same program.I believe this tuning is the reason we have a stock shortblock heads & cam car that has been making 600+ rwhp for some time now with no problems. And I have been making 700+ for almost a year and beat the snot out of it almost every weekend. I just did a leakdown test and have between 3% and 5% leakdown on every cylinder...cold. I plan to up the shot from the current 300 shot soon to put these theories to the test.

The guys who are running a direct port or large wet kit can take advantage of this buy buying a single powershot style noid and plumbing it infront of the MAF to spray a small dry shot to kick the computer over to the higher flowing "nitrous" maf tables. About $150 in parts. Just be sure to spray the dry from the begining...you will not have control unless you are spraying the dry. Reduce the size of your wet shot if necessary.

This is ideal for a street/strip car IMO

 

Nice info, so much for "dry" sucking ***.LOL.