The name of your new best friend is: Scangauge 2

[GNU]

Besides fitting perfectly snug under the dash and offering fun and somewhat useful things like MPG and GPH (Gallons per hour) and max speed for the day, the Scanguage will with some fiddeling give you current HP output and most importantly the critical IAT2 temperature values.

I've been working with the technician james DeLong at Linear Logic and he provided me with the data bus query, response and format information we need to read these values.

Here's what you need to do:
1. Buy a Scanguage (Ebay knows where to get them)
2. Plug it in to the OBD2 port of your Atom
3. Press mode twice and select XGAUGE.
4. Find an empty memory and press EDIT.
5. Program the Horsepower values:
TXD:00
RXF:400080000000
RXD:0000
MTH:000A00170000
NAM:BHP

6. save the values
7. Find the next empty memory
8. Program the IAT2 values:
TXD: 6C10F122200601
RXF: 046205200606
RXD: 3008
MTH: 00090005FFD8
NAM: IA2

9. Save the values
10. Done! The new values are now available together with the built in gauges.

[GNU]

For those of you who don't speak car. Here's an explanation of what you just did:


TXD: This is the query that you're sending to the ECU (hey, what's my IAT temp in Farenheit?)
RXF: This is the begininig of the response from the ECU. (Your IAT2 temp in farenheit is:). The ECU sends a constant stream of info so the display filters out everything except what it's looking for.
RXD: This is telling the display what part of the response you're interested in (some parts are bit priority and such and not of interest to you)
MTH: This tells the Scangauge how to manipulate the data before showing it to you. (EG. divide by two and add 32)
NAM: This is the name of the gauge as it shows up in the gauge selection.

Enojy!

[GNU]

One last thing

I did a quick study of how the temp before the super charger relates to the temp after the supercharger.
The difference at 50F ambient temp and 35mph speed on flat surface is highly related to gear selection.
The difference while in third gear is about 15 degrees. When driving at the same speed in forth gear it's 30 degrees.

I guessed that there was a difference but never guessed that the difference was that big.
My learnings from that short test is to use a lower gear during cool down laps on the track to more efficiently cool the engine.

[Terry Kennedy]

Is it waterproof?

[silver]

[quote="Arvid"]
One last thing

I did a quick study of how the temp before the super charger relates to the temp after the supercharger.
The difference at 50F ambient temp and 35mph speed on flat surface is highly related to gear selection.
The difference while in third gear is about 15 degrees. When driving at the same speed in forth gear it's 30 degrees.

I guessed that there was a difference but never guessed that the difference was that big.
My learnings from that short test is to use a lower gear during cool down laps on the track to more efficiently cool the engine.
[/quote]

are you in a 2 or a 3?

my differences are 30 degrees average on street(once it's warmed up), 80 degreees on track

and I've already spent Thousands trying to combat the heat soak in the 2.

[GNU]

I'm in a 2 with the XL SC radiator.
I'll do some more testing while driving on country roads as soon as the weather permits.

BTW, do you have the values for the air/fuel mixture?

[silver]

[quote="Arvid"]
I'm in a 2 with the XL SC radiator.
I'll do some more testing while driving on country roads as soon as the weather permits.

BTW, do you have the values for the air/fuel mixture?

[/quote]

testing around town just won't really reveal the issues with the system.

If you haven't read through the hundreds of pages on this subject I'll give you a rundown
1:  factory fan installed wired in reverse (might not be on yours)
2:  pump flow is backwards causing cavitation
3:  no bleed valve in the system as soon as you get an air bubble the system will stall
4:  intercooler not in the flow of the air, fans don't help much
5:  300's should have come with a dual bypass endplate...many did not
6:  you can upgrade to a harrop which was supposed to offer lower IAT's I have not found that to be true


I have addressed all these issues and more that I probably forgot about and I'm still at the levels above and with a custom tune I'm putting about 280whp versus under 200whp stock after heat soak

my afr's I think are 11.5 once it's leveled out.

[GNU]

Hi Silver,
We had a similar discussion when I published my results from a Trifecta tuning session

1: factory fan installed wired in reverse (might not be on yours)
Nop, not an issue on mine
2: pump flow is backwards causing cavitation
This I'm not familiar with but will do some research on the forum to learn about your findings.
3: no bleed valve in the system as soon as you get an air bubble the system will stall
I've got an additional and separate accumulator tank for the SC coolant. It sits above the factory one and should absorb any air bubbles.
4: intercooler not in the flow of the air, fans don't help much
ok
5: 300's should have come with a dual bypass endplate...many did not
I don't know what that is Again, I'll do some research.
6: you can upgrade to a harrop which was supposed to offer lower IAT's I have not found that to be true
I haven't experienced any overheating issues first hand myself (yet) but I only have a handful of trackdays under my belt. The highest ambient temperature during those days was 87F and the lowest around 60F. I did not experience any difference in top speed or acceleration between those occations
I did however feel a big difference in handling between Yokohama and Toyo tires and different wheel aligments.
Considering these cars were built in Oregon, maybe they are optimized for our Pacific Northwest climate

[silver]

you won't feel "heat soak" so much, it's not that easy to detect, but if you're IAT2 goes over 135 you're getting heat soaked.


if you don't feel it....don't bother trying to fix it, you'll just go insane in the meantime.

I can drive as hard as I can on the street and I wont' go above 140 ish anymore......but on track it easily got to 170....but now, it recovers fast and before it would get to 150 on the street and just stay there.

[GNU]

I'll keep an eye on the IAT2 in any case now that I can see it. I've noticed that it tends to go up quite a lot after hard accelerations 

I've got the air to fuel mixure values working yesterday (again, thanks to James DeLong at Scangauge/Linear Logic)
I've only tested in the garage so far. It seem to go up to and stay at 14.7:1.


Here's the XGAUGE data you need to input to get the air:fuel ratio:

TXD: 6C10F122119E01
RXF: 04628511069E
RXD: 3008
MTH: 000100010000
NAM: AFR

[John Scherrer]

14.7:1 ? Is that accurate?

That's so weak, it's nearly a fortnight ..

[GNU]

Really?

Wikipedia says:

For gasoline fuel, the stoichiometric air/fuel mixture is approximately 14.7; i.e. the approximate mass of air is 14.7 mass of fuel. Any mixture less than 14.7 to 1 is considered to be a rich mixture, any more than 14.7 to 1 is a lean mixture

[GNU]

It starts off at 14.1 and later stabilizes at 14.7

Again, this is just from a brief test inside my garage (with the door open )

[John Scherrer]

I think the ratio you're measuring is with the engine idling or running at cruise (off load) which probably is correct at 14:1

Under full load (on the road or dyno with a wide throttle), a normally aspirated engine will probably be more like 13:1 and a turbo'd or supercharged engine more like 12:1 or 11.5:1.

The richer (and safer) mixture keeps things cooler and prevents the dreaded pre-ignition, detonation and melted pistons etc.

[positron]

[quote="Arvid"]
It starts off at 14.1 and later stabilizes at 14.7

Again, this is just from a brief test inside my garage (with the door open )
[/quote]

That's most likely "commanded" rather than yield as a stock motor has a "narrow band" sensor. Which is just that, it's pretty much a 3 way answer, I'm rich.. I'm Ok.. or I'm lean.. if your not Ok, do something until your not what you are now.

You are were you are suppose to be.. at that point it was commanding 4% rich(er) until it warms up.

By comparison at WFO I'm running commanded and yielding 7.38:1 @ 4000cc/min, almost a gallon a minute..