When you turn up the boost?

[robmustang201528]

Do you need to re tune your car if you turn up the boost by 1 or two pounds? If your running 10lbs and decide it turn it up to 12, does your car need to be re tuned or will the computer recognize the change on it's own and adjust? Maybe a stupid question just need to know. Thanks

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[3beeps]

I run the same tune on 6.5 lbs up to 14-15 lbs.

 

[Boduke0220]

If it’s supercharged yes

 

[2-tone]

It's best to tune for the highest boost level you plan to run and then turn it down. It's kinda sketchy to just add boost with no changes to the tune. These engines are sophisticated and can accommodate for a lot of changes but I wouldn't run my car that way.

 

[foff667]

the thing about boost that you need to remember is that its physically working against your injectors so lets say you are running 55lb of rail pressure and 10psi of boost so in effect you are seeing 45lb of fuel pressure, if you up the boost to 14psi you'd be seeing 41lb of fuel pressure ie less fuel yet more boost. There is a chance it could cause you to lean out simply because of the physics behind it. Thats not to say you'll need to adjust the tune afterwards, however I would use the old saying trust but verify ie run some scanner logs before & after to make sure everything is good ie afr & spark/knock retard.

 

[keltymd]

the thing about boost that you need to remember is that its physically working against your injectors so lets say you are running 55lb of rail pressure and 10psi of boost so in effect you are seeing 45lb of fuel pressure, if you up the boost to 14psi you'd be seeing 41lb of fuel pressure ie less fuel yet more boost. There is a chance it could cause you to lean out simply because of the physics behind it. Thats not to say you'll need to adjust the tune afterwards, however I would use the old saying trust but verify ie run some scanner logs before & after to make sure everything is good ie afr & spark/knock retard.

true but remember you cant adjust fuel pressure unless you replace the pump basket and hat. Also these cars, unlike the older ones, stay in closed loop reading the O2s even at WOT so it will add fuel if needed, provided your injectors are big enough. that is why people can up the boost, within reason, and not need a retune.

 

[foff667]

true but remember you cant adjust fuel pressure unless you replace the pump basket and hat. Also these cars, unlike the older ones, stay in closed loop reading the O2s even at WOT so it will add fuel if needed, provided your injectors are big enough. that is why people can up the boost, within reason, and not need a retune.

Correct, hence my comment trust but verify...

 

[TripleB]

I’ve been itching to pulley down on my whipplenstage 2. But we only have 91 octane here and I’d have to pretty much add boostane every pumpntrip.

 

[keltymd]

I’ve been itching to pulley down on my whipplenstage 2. But we only have 91 octane here and I’d have to pretty much add boostane every pumpntrip.

Yeah you would drop more than you would Gabe with retard.

 

[ahl395]

I wouldn't do it at least without getting logs looked at. You may be able to get by but it isn't worth the risk if something needs to be tweaked for the additional boost.

 

[F1scamp]

I've run whipples tune with the 3.75" down to the 3.375" I always throw some type of better fuel in it at or below the 3.5". If it can monitor and adjust for cylinder pressures, cylinder temperatures, exhaust gas temperatures, air/fuel ratio, etc. what do you need to re-tune for?

 

[Davepurp]

Watch Knock for sure. I went from just over 9psi to just under 11 psi with a pulley swap on my procharger, and it went from 0 knock or adding timing to pulling timing up in the range where I was getting the higher boost ( 6500 RPMS and up or so) so I am getting a tune revision at the moment to make sure everything is good to go.

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