What to Tune First

[TFZ_Z06]

Aw nuts..... Here you go saying that this step is VERY IMPORTANT and the link to that IFR spreadsheet table is a dead link. It's not nice to tease us newbies........

just take the IFR data that is there now and make a proportional change based on your new injectors. Then adjust the
entire IFR table up/down until your STFT are close. This will get you very close if you use an inj style sim to what sin there stock.

[Rich Z]

just take the IFR data that is there now and make a proportional change based on your new injectors. Then adjust the
entire IFR table up/down until your STFT are close. This will get you very close if you use an inj style sim to what sin there stock.

Well, can you do it as simply as that when not only are there new injectors, but new intake manifold, new (427) engine, larger turbo housings on the STS turbos, and a new fuel system?

I'm just trying to figure out the current tune on my car and figure double checking what is there against what seems like SHOULD be there is a good way to try to figure this stuff out. The IFR table has to be wrong (it's a diagonal line instead of a flat line) with the mapped fuel pressure regulator I am using, or I am seriously confused about how that is supposed to work. So I would like to try to figure out what it SHOULD be.

I know my join date makes it look like I've been around here for a while, but such just is not the case. I registered when I purchased my copy of EFILive, and haven't touched it until just a week or three ago. So I'm a very raw newbie at this stuff. So right now I'm reading the hell out of this forum. And not planning to flash anything until I've got a good idea of what I am doing. Otherwise I would surely just make things worse. Not that the car is running bad now, but there does appear to be some rough edges that need to be taken care of.

Thanks.

[TFZ_Z06]

Well, can you do it as simply as that when not only are there new injectors, but new intake manifold, new (427) engine, larger turbo housings on the STS turbos, and a new fuel system?

I'm just trying to figure out the current tune on my car and figure double checking what is there against what seems like SHOULD be there is a good way to try to figure this stuff out. The IFR table has to be wrong (it's a diagonal line instead of a flat line) with the mapped fuel pressure regulator I am using, or I am seriously confused about how that is supposed to work. So I would like to try to figure out what it SHOULD be.

I know my join date makes it look like I've been around here for a while, but such just is not the case. I registered when I purchased my copy of EFILive, and haven't touched it until just a week or three ago. So I'm a very raw newbie at this stuff. So right now I'm reading the hell out of this forum. And not planning to flash anything until I've got a good idea of what I am doing. Otherwise I would surely just make things worse. Not that the car is running bad now, but there does appear to be some rough edges that need to be taken care of.

Thanks.

A new intake manifold won't change idle vacuum or idle airflow, the fuel system should be coming in at the same PSI as the old one, a 427 idles very close to the same airflow as a 346 (my 12:1 416 does), proportionally more, and unless you stand on it the boost won't affect idle.

IF that turbo is low boost, MAYBE you can keep the MAF. If you PEG that meter and get error codes,
you will have to go to COS5. COS5 is designed to tune boosted apps to 3 BAR. Check it out under custom operating systems. In my sig, you will see that I run it on my car and I have provided a stock file.

You are obviously correct to be careful w/that monster and I certainly respect that.

I would consider tweaking injectors rates to fit idle using STFTs (0 to slightly negative; clear fuel trims then adj IFR), then for top end you can make sure either your MAF is tuned to the expected AFR (preferably to AFR expected in the PE vs RPM table) or done via COS5 boost table, both with a wideband. That will get you very close.

Easier said than done! Good luck. Lots of good info on the site.

[Dirktdolman]

Does anyone have a current location to find the IFR Spreadsheet? The one I downloaded from post 1 is blank.

[Gelf VXR]

This one?

[Dirktdolman]

It is a different title but I hope it is the same.

THANK YOU

[Gelf VXR]

I think it is

[Gelf VXR]

[Dirktdolman]

OK just checking if I have done this correctly

I found this



I took that info and put it into WitchHunter converter page to convert the 220 cc/min to 21 lbs/hr



Then I took the data from the first two pictures and placed it into the Injector flow rate calculator.



My concern comes when I compare the results of the calculator to my tune file.



Are they supposed to be that different? I noticed on the calculator the numbers increase with vacuum but the tune does not.

[joecar]

Dirktdolman,

Does your FPR have a MAP reference (i.e. air hose connecting FPR to intake manifold)...?

Did you measure rail pressure (with MAP reference hose disconnected), is it 43.5 psi...?

Do your injectors flow 21 lb/hr at 43.5 psi (3 bar)...?