SDS tuning (timing)

[1FastCSX289]

Hey guys, I recently purchased TD member Josh's (theCSXmachine) 89 CSX. Specs here: http://www.viplift.com/shelby.html

I am trying to tune the computer (SDS-EM4F). The fuel and ignition curves seem a bit out of wack. Im running into some knock and my first thought was to back off the timing (its pig rich). I did some research on the yahoo d-cal group and got some sample timing maps. I was going to copy the Mopar Performance 87 T2 cal. When I looked into it, its almost as aggressive as what is already programmed into the SDS. Should I use the stock 89 T2 timing map to start with....or this map just way too conservative? Maybe a stock 87 T2 map? Any other ideas on where I should start with timing this thing?

I am completely new to SDS and know virtually nothing. So any good advice is welcome.

I dont know if you have to be a member of the group to view this, but here are the sample maps that I was looking at on the yahoo d-cal group:

http://f5.grp.yahoofs.com/v1/sGbRRP7LCYa7kW_glMdy_BSZ2BR2ACPyVvKz63zvcX8As9ds0u O0JydkaXDCWh3bercE3UPfdEkj7PEhdGnf0J38zwcBSfAtH4-paw/Spark%20Advance%20Comparisons/87MPT2vs87T2sparkadvance.pdf

EDIT: ONE MORE question. Why is the 89 T2 spark advance so much more conservative than the 87 spark advance? Is cylinder head design an issue? The CSX has a swirl head.......so should I go with the 89 curve?

Heres what I mean:
http://f1.grp.yahoofs.com/v1/sGbRRKksRAC7kW_gdgVj-D61qTyVCQmpW_W_8g59Dplo7Hedob8fnkdvuS31gunhLVrKX6L 74ZXEZODJEuU5KgaCZwIwoK70F2y55A/Spark%20Advance%20Comparisons/89T1vs89T2sparkadvance.pdf

[BadAssPerformance]

Im running into some knock and my first thought was to back off the timing (its pig rich).

So it knocks, and its rich???

To start out safe, I would just set your timing table at all 12* (assuming it is higher now) for anything above 2000rpm and 5psi MAP. If it runs ok then, I would GENTLY lean out the fuel first, them increase timing.

btw, the links dont work for me.

[1FastCSX289]

So it knocks, and its rich???

To start out safe, I would just set your timing table at all 12* (assuming it is higher now) for anything above 2000rpm and 5psi MAP. If it runs ok then, I would GENTLY lean out the fuel first, them increase timing.

btw, the links dont work for me.


Yes, its rich and im getting knock (according to the SDS). It could be that its picking up false knock, but its also entirely possible that the timing is too far advanced. So, set the timing to 12*? Thats along the lines of a stock 89 T2 program.

If the links dont work, it may be because youre not a member of the d-cal group on yahoo. I wasnt sure if they would work. You could sign up....theres some pretty good info there to be had!

[Speedeuphoria]

can't you adjust the sensativity for the knock sensor on the SDS?
I assume you already reved it in neutral to assure that it wasn't just engine noise?
I also assume that you are not running 87 octane?
I am no expert but I would try the more conservative 89 timing and see what happens
do you hear the ping?
is the knock sensor known to be good?(try using teflon tape on it to lessen the sensativity)

[87csx2.4]

What kind of head is on the car?Is it an auto or manual ?what size injectors?Is it a 2bar or 3 bar?To be safe I would go into rpm ignition and start at 10 degrees in the 500 rpm and bump it up gradually to 30 total by 3000 rpm and then put 30 total across the board from there on up.Then go into ignition advance/retard in the map and pull 1 deg. of retard per pound of boost starting at 3 psi on up.If you would like more help answer some of the ?'s I have maps and timing schedules for all kinds of vehicles that Ive ran 8 valve and dohc,race gas and pump gas.[edit]I didnt read the add for the car I have a map and timing curve that should work perfect for you.

[1FastCSX289]

What kind of head is on the car?Is it an auto or manual ?what size injectors?Is it a 2bar or 3 bar?To be safe I would go into rpm ignition and start at 10 degrees in the 500 rpm and bump it up gradually to 30 total by 3000 rpm and then put 30 total across the board from there on up.Then go into ignition advance/retard in the map and pull 1 deg. of retard per pound of boost starting at 3 psi on up.If you would like more help answer some of the ?'s I have maps and timing schedules for all kinds of vehicles that Ive ran 8 valve and dohc,race gas and pump gas.[edit]I didnt read the add for the car I have a map and timing curve that should work perfect for you.

Sweet. I got your PM and I will call you later tonight!

[1FastCSX289]

can't you adjust the sensativity for the knock sensor on the SDS?
I assume you already reved it in neutral to assure that it wasn't just engine noise?
I also assume that you are not running 87 octane?
I am no expert but I would try the more conservative 89 timing and see what happens
do you hear the ping?
is the knock sensor known to be good?(try using teflon tape on it to lessen the sensativity)

Yes, i played with the sensativity and I think its fals knock. Thanks for the advice. I will try the teflon too.

[Dietro]

The prior owner to Josh had the system installed on an engine with an extremely good flowing head and a Garrett GT31 turbo. So, unless Josh had it tuned for a more modest head and turbo, I'm not at all surprised you are seeing black smoke as it's expecting quite a bit more air. ;)

[1FastCSX289]

The prior owner to Josh had the system installed on an engine with an extremely good flowing head and a Garrett GT31 turbo. So, unless Josh had it tuned for a more modest head and turbo, I'm not at all surprised you are seeing black smoke as it's expecting quite a bit more air. ;)


Hmmm.... The car does have a GT30R turbo and the head is supposed to flow similiarly to the Enforcer 3. Do you know differently?

[87csx2.4]

The prior owner to Josh had the system installed on an engine with an extremely good flowing head and a Garrett GT31 turbo. So, unless Josh had it tuned for a more modest head and turbo, I'm not at all surprised you are seeing black smoke as it's expecting quite a bit more air. ;)Hey todd didnt the prior owner live over in the chattanooga area.

[Dietro]

Hmmm.... The car does have a GT30R turbo and the head is supposed to flow similiarly to the Enforcer 3. Do you know differently?

(Just read the specs from the link.) Do you have the custom built equal length header? I don't know about the head that is on the car now, but Josh purchased the SDS system along with a header, turbo and the previously mentioned HIGH flowing head all as one unit. He sold the head some time ago.

I'll stick with my guess that the current head doesn't flow as well as the one he sold and the SDS was originally tuned for....

Sidebar about the header. IIRC, the head it was originally mounted on was flow benched with the header on and without it on.....it made no difference. IOW, the header generates virtually no back pressure.

[Dietro]

Hey todd didnt the prior owner live over in the chattanooga area.

He still does.... ;)

[1FastCSX289]

(Just read the specs from the link.) Do you have the custom built equal length header? I don't know about the head that is on the car now, but Josh purchased the SDS system along with a header, turbo and the previously mentioned HIGH flowing head all as one unit. He sold the head some time ago.

I'll stick with my guess that the current head doesn't flow as well as the one he sold and the SDS was originally tuned for....

Sidebar about the header. The head it was originally mounted on was flow benched with the head and without it.....it made no difference. IOW, the header generates virtually no back pressure.


Thats good to know about the header.......but why the heck did he sell such a nice head? That is the one thing that causes concern for me, because he couldnt produce flow numbers for the head. He said that the porter just duplicated an enforcer 3 head. But why would he go through the trouble of having another head ported if he had one already that flowed better? Josh seems like a straight shooter. But thats concerning.

[Dietro]

I have no idea about his motivations for selling the head, but let's just say the head he sold off is kind of rare. ;)

[1FastCSX289]

I have no idea about his motivations for selling the head, but let's just say the head he sold off is kind of rare. ;)


So he got a boat load of money for it and put a less expensive head on the car. Gotcha.;)

[Dietro]

You said it, not me.... :)

Do a search for: "+2/-2" over at TD.com. I don't think there were any threads here about the head, but you might check.