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11 second all motor club
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Discussion Starter #1
Ok i know i come from a whole different world of car tuning. im used to smaller displacement (literaly half haha) inline 6 with a massive turbo.

however there are a few things in this world that i know to be constants

1) more air in more air out = more hp
2) Maf are a major restriction for the air in portion of the equation
3) removal of a MAF usually = good hp numbers gained

here is a product i used to hear alot of people love on my 94supra turbo that gave some tune ability to the fuel air ratio without modding the computer, but also would replace the MAF with a speed density system (not even sure this works well with a non FI situation but thought i would check!)

http://www.mapecu.co.nz

has anyone thought about this? just wondering what the thoughts are on this one!
 

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You're going to find that it's hard to compare any aftermarket support tuning wise to the 3rd gen engines and even 4th gens although they're not quite to the level of the 3rd gens.....yet.

www.hptuners.com
www.efilive.com

Those 2 are all you need to know. Although for a short plug, I'll say in a non-boosted app with the speed density enhanced os from hptuners, you can do real time tuning....awesome...
 

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I'm gonna get you!
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It easier and more cost effective to just get tuning software. you pay a little more and can change everything.
 

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11 second all motor club
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Discussion Starter #4
spd98 said:
It easier and more cost effective to just get tuning software. you pay a little more and can change everything.
so you can delete the MAF through tuning software? thats pretty cool, man i knew these v8 computers were easy but i didnt realize they were this easy haha
 

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efilive evangalist
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Do it man. You will have great fun.

Delete MAF and even MAP if you want. Some tuners allow fueling based on rpm and tps only. (Alpha-n)
 

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I haven't seen anyone reporting huge gains with MAF delete on our goats.
MAF is harder to tune but makes for better throttle response (in my humble opinion).

Ive been running SD for a while, and it run ok and makes power, its rough when cold and at low rpms. Part throttle responsiveness is sluggish.

I bought a bigger (LS6) MAF just havenot gotten around to calibrating it yet.
 

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the size of MAF does NOT matter. been proven empirically, so drop it.

going with Speed Density is not about 'gains' as if MAF was a restriction, but gains from fine control (accounting for all the tiny changes in IAT, MAP, RPM, VE instantly), and not having limits (not more 512g/sec ceiling)

MAF is not harder to tune, it's one histogram (well, 2 for LS2's split MAF tables)

FI and MAF on GM computers is an inherent hack--SD is the solution.
 

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redhardsupra said:
MAF is not harder to tune, it's one histogram (well, 2 for LS2's split MAF tables)
I really don't want to get into an argument with because of your reputation and contributions to the tuning community (I use your spreadhseet to do the MAF calc, thanks!) but for us mere mortals, MAF tuning *IS* harder than SD tuning. Its harder to get our heads around, harder to do the calcuations, the math is harder, etc.

FI and MAF on GM computers is an inherent hack--SD is the solution.
You of course are entitled to your opinions, but with my specific car, when ive had it tuned in SD mode versus tuned in MAF mode, the MAF mode seems to me to have better throttle response. I am of course willing to accept the possibility that my SD tune wasn't perfect, but as you say, SD tuning isn't that hard.

Would you not also agree, that the MAF responds quicker to atmospheric changes, such as sudden altitude changes (quite common with us Colorado folk)?
 

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11 second all motor club
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Discussion Starter #9
Wow didnt mean to start a debate. I am just coming from a different background where the MAf was a huge huge huge restriction on our power making abilities. of course that was a factory FI situation and a much smaller MAF. It was just an idea haha :)


so while i have you guys lookin at this thread, if i were to get a tuning application could i buy a second ecu, so i could switch back to stock easily??
 

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debates are good, they help people learn. no gnashing of teeth here!

you dont need another ecu. just buy the tuning software, and you save your old stock config to your laptop. flash back if you need to later.
 

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redhardsupra said:
the size of MAF does NOT matter. been proven empirically, so drop it.

going with Speed Density is not about 'gains' as if MAF was a restriction, but gains from fine control (accounting for all the tiny changes in IAT, MAP, RPM, VE instantly), and not having limits (not more 512g/sec ceiling)

MAF is not harder to tune, it's one histogram (well, 2 for LS2's split MAF tables)

The MAF is not harder to tune. It is only harder to produce a smooth curve that is still correct across the board. This takes some work (3rd or 4th order polys). I would imagine most don't do any of that but being an engineer I can't help it :)

Tim
 

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MAF curve is a 3rd order poly, as it follows King's Law. I have a very complicated SAE paper describing it, i posted it somewhere on ls1tech.

my approach is to get VE perfect, then map these VE-based airflow numbers onto MAF, and then once that's close, i actually do a 3rd order poly regression fitting to find the formula for it, and make the calibration from that. works like a charm every time.

and as for throttle response, i like SD better, i do roadracing, so being able to nail the throttle precisely at the apex is important.
 
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