does lower, require a new tune

[onecobra2fear]

My power numbers are 517/478 to the rear
My mods.

2.8 upper
steig, stage IV
twin focus fuel pumps
ngk7 plugs
elec. water pump
accufab t-body
jlt cia
#60 injectors
LFP heat exchanger
100mm aux.
Pred. tune
Would I need a new tune if I add a 4-6lb lower.

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[Wiked03]

Theoretically a good tune should compensate for the added boost… provided you don't peg the MAF or max out the pump/injectors.

But I would certainly dyno it and/or datalog to make sure all is well.

 

[onecobra2fear]

Theoretically a good tune should compensate for the added boost… provided you don't peg the MAF or max out the pump/injectors.

But I would certainly dyno it and/or datalog to make sure all is well.

do you think loweres are worth the trouble?

 

[SLASH]

IMO all your gonna do is over spin the eaton, it looks like you are maxing hp with your mods. a bigger lower will try to produce more boost, but i think you would be pushing it. go to a whipple or k/b

 

[ChicagoMike]

A 2.8 upper with a 4 or 6 # lower is overkill. I think that equals over 18 PSI. Too much heat and too much spinning.

2.8 upper with a 2 # lower is what is recommended - or 2.93/4# or 3.1/6#. You'll also need a bigger alternator pulley.

Not worth the trouble, I'm running 3.1 upper/6# lower - 520HP/520TQ with the ported blower. YES you'll need a retune, more boost = leaner, and you'll probably peg the maf.

If you don't mind wasting money on another tune and shortening the life of your eaton and spending money on a MAF and cooling mods, then go for it (like I did, but I went all the way the first time around - if I was in your situation, I'd go right for the KB or whipple)

 

[Wiked03]

do you think loweres are worth the trouble?

With a 2.8 upper I wouldn't go bigger than a 2lb lower.

Do you have a MAF extender of some kind? My MAF was damn near pegged with just a 2.76 upper, so I wouldn't be surprised if you weren't pegged or very close.

YES you'll need a retune, more boost = leaner, and you'll probably peg the maf.

It will only lean out if it was tuned improperly or the MAF pegs. Larry frequently changes upper pullies on his whipple to up the boost at the track without making any tune changes.

 

[doug@performance]

With that pulley combo you would be spinning that S@#$ out of that blower that would probably cause a lot of heat along with shorten the life of the Eaton. Your set up makes good power now so you i would recomend just to upgrade to the Whipple or K.B. But as like the others are telling you,You will need a MAF or atleast a extender.
Thanks
Doug

 

[Dana]

I'd go for it, provided you installed a bigger MAF, say the SCT2400.
Then when you figure out that still isn't enough power and you install the Whipple or KB, you're half way home. You will have almost all the supporting mods in place already.
I probably wouldn't go bigger that a 4# lower for now though.
You might consider a BAP too.
Dana