99 ls1 cold air, headers , and exhaust tune?

[hdsvette]

ok im new here...and to the efi live world....just installed kooks long tube headers, x-pipe, high flow cats, and borla hi flo cat back system as well as an afe cold air intake on a 99 vette.....my question is does this tune require changing?? Can i tune without using a wideband O2? where do i start?? lol i am using flashscan v2...any help would be appreciated...thanks!!

[joecar]

Hi hds,

welcome to the forum :cheers:

you could get by without a tune, but you will get the most from the headers/exhaust/coldair by tuning the VE and MAF tables using a wideband;

without a wideband you might want to look at the Calc.VE tutorial (Start->All Programs->EFILive->V7.5->Doc->Tutorials)...
the Calc.VE tutorial calculates/corrects both VE and MAF tables using LTFT, MAF, MAP, RPM, DAT(IAT/ECT temperature blend);
the Calc.VE tutorial won't give you WOT corrections, you have to extrapolate the VE/MAF tables to the upper regions;
also see posts #169, #200: showthread.php?13152-New-Tuning-Tutorial-WeathermanShawn (http://forum.efilive.com/showthread.php?13152-New-Tuning-Tutorial-WeathermanShawn&p=120121&viewfull=1#post120121)

a wideband will give you better results and will give you WOT regions;

changing the plumbing ahead of the MAF typically changes how the MAF behaves (that's why I say to correct the MAF table);
headers changes your engine's VE (cylinder fill airmass), so the VE table has to be corrected;

without VE/MAF corrections you could probably get by (the LTFT's will correct fueling, and the residual positive LTFT's get applied at WOT), but the PCM is not modelling the cylinder airmass correctly so you will see only partial gains from headers; some tuning is definitely recommended.

[Gregs]

yeah you'll need a wideband

[joecar]

+1

hds, if you think about how much the headers and catback cost, you will see that the wideband is fairly cheap.

[hdsvette]

+1

hds, if you think about how much the headers and catback cost, you will see that the wideband is fairly cheap.

hey thanks so much for the info guys.....yes i agree....the wideband is cheap....i will definatley get one.....im just new to all this...still getting it all figured out!

[n8dogg]

If you take a look at some of my first posts/threads you will see I was just about in the same boat as you. I just wanted to learn how to tune, I thought my car was running well as it was. Funny thing is, my LTFT's were near 15% and my injectors were maxing out. All because my MAF needed correction. Take things slow. Start with just playing around with the scan tool and logging. There are a few guys on here that are tremendous help and very patient with the noob questions. We all gotta start somewhere.

Good to see another Vette owner... have fun!

[joecar]

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