Want a little more HP without breaking the bank.

[Whitedevil95]

I am pretty sure the reason Lund doesnt tune the Roush kits is because they are MAP based and do not have a MAF on the 2018+ kits.

Sponsored

 

[brucelinc]

Yep, looks like it commands about 17 deg spark at wot, assuming ect and mct are normal. It will advance it up to 3 deg and wind up at 20 if octane is available.

Question for you, Mike: Let's say the Roush cal pulls 3 degrees of timing when IAT2 reaches 150 degrees. If the car has sufficient octane to achieve the 20 degrees when temps are lower, would it still pull the same 3 degrees.....giving the 17? If so, it seems that higher octane would be helpful in high temp areas.

(I have no idea if the cal pulls timing at certain iat2 levels or how much. My question is just theoretical.)

 

[engineermike]

Question for you, Mike: Let's say the Roush cal pulls 3 degrees of timing when IAT2 reaches 150 degrees. If the car has sufficient octane to achieve the 20 degrees when temps are lower, would it still pull the same 3 degrees.....giving the 17? If so, it seems that higher octane would be helpful in high temp areas.

Looks like at 151 deg charge temp it actually “pulls” a whopping 9 deg of timing at 5000+ rpm. Understand that this is a borderline spark “correction”. As such, it is applied to the 17 deg I posted earlier, so the initial timing command is 8 degrees. The 3 deg knock advance maximum is applied to that number, so it could go up to 11.

The intent of the charge temp timing “pull” is to match the actual increase in knock potential. So, if everything is calibrated right, then the knock threshold drops the same as the timing command reduction.

The roush phase 2 pulls twice as much timing as stock and predator over the same span, which tells me roush is fudging on the side of safety and REALLY wants to prevent knock at high charge temps.

 

[Cory S]

Question for you, Mike: Let's say the Roush cal pulls 3 degrees of timing when IAT2 reaches 150 degrees. If the car has sufficient octane to achieve the 20 degrees when temps are lower, would it still pull the same 3 degrees.....giving the 17? If so, it seems that higher octane would be helpful in high temp areas.

(I have no idea if the cal pulls timing at certain iat2 levels or how much. My question is just theoretical.)

IAT and knock are two different tables. So yes, even if spark is commanded to be pulled at 150° IAT, it’s going to be pulled even if zero knock is present.

 

[Old5.Oguy]

With headers and a VMP tune I ran a 10.4@133 on a 19" et street ss... I added a KC and my IAT2's are respectable now.... It'll be interesting to see what I run next. I want to add a BAP too.... I think I'm in need of fuel at the top end of my runs....

I’ve been back and forth with the tune, either VMP or PBD.

Sponsored