keydiver/afc

[erald01]

i was just wondering, do u really need and afc with the keydiver chip, cause i got my keydiver and im about to install it but i dont have an afc or a datalogger. i think im gona get a dsmlink down the road. i dont think there should be a problem with the car running without the afc should it? my upgrades are

evo3 16g
evo3 manifold and 02 housing
afpr
650 fic injectors
walbro255lph
fmic
3" apexi

[16gpoweredgsx]

You should't need to use a safc, as long as you chip is setup for your mods, you should be fine. Although you should get a datalogger a.s.a.p., so you know what your car is really doing and how it will react to the mods.

[el guapo]

Well look at this way. its gonna be closer than it was. He does pretty good with those chips, mine was only 3% off when i finally tuned it. I'd drive it if i were you.

[TunaTalon]

Expect the Keydiver chip to be very close. I ended up with 42.5 PSI base fuel pressure on my tune with 720s.
If you want to change later the $20.00 charge for a reburn is cheap , even for DSM'ers.

[bling5tatus]

Does Jeff compensate for inj dead time or just the size of the injectors? Does he ask specifically what brand/size the injectors are or just what size they are?

[Black_Bullet]

Originally Posted by erald01

i was just wondering, do u really need and afc with the keydiver chip, cause i got my keydiver and im about to install it but i dont have an afc or a datalogger. i think im gona get a dsmlink down the road. i dont think there should be a problem with the car running without the afc should it? my upgrades are

evo3 16g
evo3 manifold and 02 housing
afpr
650 fic injectors
walbro255lph
fmic
3" apexi

Yes that set up will work fine, but why not get bigger injectors... Get the 850s at least
why hold your self back since you have a means to control them all the same...

Originally Posted by 16gpoweredgsx

You should't need to use a safc, as long as you chip is setup for your mods, you should be fine. Although you should get a datalogger a.s.a.p., so you know what your car is really doing and how it will react to the mods.

I agree about the logger, and a wideband should be thrown in with that list as well.

Originally Posted by TunaTalon

Expect the Keydiver chip to be very close. I ended up with 42.5 PSI base fuel pressure on my tune with 720s.
If you want to change later the $20.00 charge for a reburn is cheap , even for DSM'ers.

I run the n/t fpr at 48 base psi, it lowers fp over run a good amount and makes your injectors flow like there bigger. But i wouldnt run this fpr if you plan to run beyond 25psi because fuel pressure relief valve will kick in at that point.

Originally Posted by bling5tatus

Does Jeff compensate for inj dead time or just the size of the injectors? Does he ask specifically what brand/size the injectors are or just what size they are?

Just be specific on telling him your goals w/ the car and what parts you have in the mix.
He does compensate for inj dead time and global and all that, you can go on dsmlink boards and find out what your deadtime and global % should be for your injectors/fuel pressure and ask him what he had in mind and compare and see if thats the amount of deadtime you want. Or if you dont feel like looking i believe the global formula is

450 / (inj size you run) / 1.2864 - 1.0 = _________ - 1.0 = ( This would be your global %)

Mines is at like 315 us inj dead time w/ 41% global, i burn my own chips so im going to lower my dead time to 310us on my 850s... Wont change much but generally the higher the deadtime number the richer the burn, the lower the leaner.

[steve]

Originally Posted by bling5tatus

Does Jeff compensate for inj dead time or just the size of the injectors? Does he ask specifically what brand/size the injectors are or just what size they are?

Yes, he asks and needs to know what brand so that he can correct the deadtime and global.

Steve

[erald01]

Originally Posted by Black_Bullet

Yes that set up will work fine, but why not get bigger injectors... Get the 850s at least
why hold your self back since you have a means to control them all the same...



I agree about the logger, and a wideband should be thrown in with that list as well.



I run the n/t fpr at 48 base psi, it lowers fp over run a good amount and makes your injectors flow like there bigger. But i wouldnt run this fpr if you plan to run beyond 25psi because fuel pressure relief valve will kick in at that point.



Just be specific on telling him your goals w/ the car and what parts you have in the mix.
He does compensate for inj dead time and global and all that, you can go on dsmlink boards and find out what your deadtime and global % should be for your injectors/fuel pressure and ask him what he had in mind and compare and see if thats the amount of deadtime you want. Or if you dont feel like looking i believe the global formula is

450 / (inj size you run) / 1.2864 - 1.0 = _________ - 1.0 = ( This would be your global %)

Mines is at like 315 us inj dead time w/ 41% global, i burn my own chips so im going to lower my dead time to 310us on my 850s... Wont change much but generally the higher the deadtime number the richer the burn, the lower the leaner.

thanx that formula helps alot..

[DGajre777]

erald01 - As for your original question -

"Do I have to use an AFC with my chip?
Generally, yes. Although the changes I make to the Global Fuel and MAS Compensation get VERY close, and make it easier to tune, it is still recommended that you have some tunability, such as an Air-Fuel computer or a GOOD adjustable Fuel Pressure Regulator. In addition, every car is different, so you may require more/less fuel depending on your situation - www.dsmchips.com"

Basically, if you see knock on your boost gauge (that hopefully you had burned to see knock sum), then either turn the boost down or bump up the fuel pressure.

And if you don't want to use the formula, here are the numbers from the DSMLink manual.

Size (cc/min) Global (%) Dead time (ms)
RC 550 -18% 180
Hahn 625 -18% 180
Denso 660 -31% 180
Denso 720 -38% 450
PTE 580 -16% 180
PTE 680 -30% 210
PTE 780 -40% 315
PTE 880 -46% 330
FIC 650 -31% 315
FIC 750 -40% 315
FIC 850 -47% 315
FIC 950 -53% 315

Originally Posted by Black_Bullet

I agree about the logger, and a wideband should be thrown in with that list as well.

Or just ask Jeff at DSMChips to burn your chip with the A/F ratio that you want to run (for example 11.5:1 on 93 octane) and you won't need to get a wideband.

Originally Posted by Black_Bullet

I run the n/t fpr at 48 base psi, it lowers fp over run a good amount and makes your injectors flow like there bigger. But i wouldnt run this fpr if you plan to run beyond 25psi because fuel pressure relief valve will kick in at that point.

The original poster has an AFPR, he won't need to worry about stock fuel pressure regulator overrun.

[Black_Bullet]

Originally Posted by DGajre777

erald01 - As for your original question -
Do I have to use an AFC with my chip?
Generally, yes. Although the changes I make to the Global Fuel and MAS Compensation get VERY close, and make it easier to tune, it is still recommended that you have some tunability, such as an Air-Fuel computer or a GOOD adjustable Fuel Pressure Regulator. In addition, every car is different, so you may require more/less fuel depending on your situation

Basically, if you see knock on your boost gauge (that hopefully you had burned to see knock sum), then either turn the boost down or bump up the fuel pressure.

And if you don't want to use the formula, here are the numbers from the DSMLink manual.

Size (cc/min) Global (%) Dead time (ms)
RC 550 -18% 180
Hahn 625 -18% 180
Denso 660 -31% 180
Denso 720 -38% 450
PTE 580 -16% 180
PTE 680 -30% 210
PTE 780 -40% 315
PTE 880 -46% 330
FIC 650 -31% 315
FIC 750 -40% 315
FIC 850 -47% 315
FIC 950 -53% 315


Or just ask Jeff at DSMChips to burn your chip with the A/F ratio that you want to run (for example 11.5:1 on 93 octane) and you won't need to get a wideband.


The original poster has an AFPR, he won't need to worry about stock fuel pressure regulator overrun.

Oh ok thats good about the afpr, and I forgot to add the deadtime chart thanks.. Also to the OP yea you can get a set air fuel ratio by Jeff that wont be off much, but I still think its good to have a wideband.... My opinion though...

[erald01]

Originally Posted by DGajre777

erald01 - As for your original question -

"Do I have to use an AFC with my chip?
Generally, yes. Although the changes I make to the Global Fuel and MAS Compensation get VERY close, and make it easier to tune, it is still recommended that you have some tunability, such as an Air-Fuel computer or a GOOD adjustable Fuel Pressure Regulator. In addition, every car is different, so you may require more/less fuel depending on your situation - www.dsmchips.com"

Basically, if you see knock on your boost gauge (that hopefully you had burned to see knock sum), then either turn the boost down or bump up the fuel pressure.

And if you don't want to use the formula, here are the numbers from the DSMLink manual.

Size (cc/min) Global (%) Dead time (ms)
RC 550 -18% 180
Hahn 625 -18% 180
Denso 660 -31% 180
Denso 720 -38% 450
PTE 580 -16% 180
PTE 680 -30% 210
PTE 780 -40% 315
PTE 880 -46% 330
FIC 650 -31% 315
FIC 750 -40% 315
FIC 850 -47% 315
FIC 950 -53% 315


Or just ask Jeff at DSMChips to burn your chip with the A/F ratio that you want to run (for example 11.5:1 on 93 octane) and you won't need to get a wideband.


The original poster has an AFPR, he won't need to worry about stock fuel pressure regulator overrun.

the thing is that i have a dsm link also but i wanted to run it with the keydiver chip till i get used to the dsm link, but i did burn the boost gauge as the knock sum but i have no idea what the knock sum is all about can some one explain it briefly..

[DGajre777]

Originally Posted by erald01

the thing is that i have a dsm link also but i wanted to run it with the keydiver chip till i get used to the dsm link, but i did burn the boost gauge as the knock sum but i have no idea what the knock sum is all about can some one explain it briefly..

You do know that you can't run the keydiver chip and DSMLink at the same time, right?

Knock sum - On DSM's, the gauge will normally rest on the "-7", for 0 knock sum. It will rise 5 knock sum per division on the gauge, so "0"=5 knock sum, "+7"=10 knock sum, and "+14"=15 or more knock sum.

You want to see knocksum less than 5, which is basically between the first and second line (knock sum of 0-5) on the stock boost gauge coded to see knock sum. When you start to pull timing, you'll normally see knock (retard). 2Gs and 1Gs will retard 1 degree of timing (knock retard) for about 3 knock sum.

More info here - knock what is a sfe knock and what would be a bad knock?

There was a thread somewhere about how the knock sum on DSMchips.com website was wrong, but I can't find that thread anywhere.

[oldman]

Originally Posted by erald01

yea im aware that u cant use the keydiver with the dsm link, but when i feel comfortable with the whole tunning urself thing ill just swap the chips from the computer. yeah i was never sure what the knock sum was all about it, but thanx for explaining

Seriously, I'm getting pretty sick and tire of asking you to use proper grammar, spelling, punctuation and caps in tech sections, I hate using the warning system or close threads for this but I will if I must.

To answer your question, yes, you should have an AFC and logger with eprom chip setup for fine tuning.