timing vs. boost

[TRBON8R]

Everyone says that running more boost is better than more timing, but at what point?

Right now I'm running an ME chip with 26* timing and 24 psi boost with no knock. If I were to cut the timing back to the 18* setting, how much boost would I have to run to get performance similar to what I'm getting now? Is there any sort of rule of thumb on this? Would 26-27 psi even be possible with my TA49 on 18* timing or is that too far out of the efficiency range for the turbo? This car only sees 114 octane fuel. Thanks.

 

[750H.P.V6]

Ben,

You might be able to squeze a bit more boost out of the TA49 but you are really close to the end of the road efficiency wise. I would tell you that another 2 degrees timing might be OK but all told your are pretty much maxed out. You might be able to lean the car out a bit too. How are the o2 mv's?

Neal

 

[at7we2]

good question

hey TRBON8R,

I'm glad you posted that question. I'd like to know the answer too. I recently switched to a Translator Plus and an Extender chip (*awsome* setup by the way!). Since I've got the ability to adjust timing, fuel and boost now, I'm not sure which is better- more boost or more spark.

simply based on the principle of "Flow = Power", it would stand to reason that more boost (and fuel) is better than more timing advance. but I'm sure there is a point of diminishing returns.

I've played around with a few small tweaks to the fuel mixture and timing with good results, but it seems like you could *theoretically* keep increasing the timing until you get knock, then increase the fuel to suppress the knock, then increase the boost until you get knock again and then increase the fuel again -- then repeat this whole process until you run out of injector (or fuel pressure). However, I'm pretty sure it's not that simple. For now, I've eliminated fuel pressure as a variable (set to 45 psi static as per Extender chip instructions). It a good thing too, otherwise I'd probably have the car so far out of tune it would barely run!

So, what parameter do you "chase" for maximum power?

Hope I didn't hijack the thread, I think I'm looking for the same inforamtion.

Rob

 

[TRBON8R]

Originally posted by 750H.P.V6
Ben,

You might be able to squeze a bit more boost out of the TA49 but you are really close to the end of the road efficiency wise. I would tell you that another 2 degrees timing might be OK but all told your are pretty much maxed out. You might be able to lean the car out a bit too. How are the o2 mv's?

Neal

Hey Neal,

Thanks for your help. You and Len Freeman helped me run my best time in Vegas a couple years ago. Wish I could make it to Vegas this year, but I've got some trans issues that still need to get sorted out.

I agree with you that my TA49 is either maxed out or pretty darn close. I use EGTs rather than O2s for tuning. Right now I'm seeing temps in the 1550 to 1575 range with 43 psi FP line off. I could probably lean it out a bit more, but I prefer to err on the side of caution.

at7we2, no highjack at all. Sounds like we are after the same info.

 

[2QUIK6]

You must remember that the higher the psi, the hotter the air is going to be so at some point more boost will not add any more hp. You must find that "sweet spot" for your turbo where its at its best efficiency, and then up the timing till KR occurs. Only testing will tell because every car is a little different. Also depends on other mods to help air flow etc.. I've seen car run wickedly fast with huge turbos and 15-18# of boost with loads of timing...for a huge size turbo at that pressure, heat gain from the compressed air would be almost nothing which is why they respond so well to more timing.