i just got off the phone with brian from bg performance and he told me that auto tapping and using a maft is not as accurate as getting a full tune. that i will have to keep on unplugging my battery because the computer tries to relearn itself. and a full blown dyno tune will be more accurate measure for my a/f ratio. and i will be better off in the long run with a dyno tune. so i should spend the five hundred dollars or go ahead and get my car auto tapped and use the maft. i would much rather get it tunned but damn that is very pricey. i am not that knowledgable about my cars pcm, but i really want to get some gains from these headers! so i guess my overall question is, is this my only concern my a/f ratio, or is it more things that should require a dyno tune. i mean it is cheaper? but brian told me that atap is not a good thing to use to read your a/f ratio. it doesnt use a broadband reading like a dyno tune would, because you a/f ratio changes and auto tap cant read it as good. SO I NEED ADVICE PLEASE!!! i hate computer cars!!! why cant these cars be carburaters!!!! GOD! thanks!
1998 trans am ws6 M6

 

He's right. Dyno tuning with a LS1Edit and a good tuner is the best bet.

But when you change your mods, you'll have to have it tuned again (sometimes).

An MAFT let's you change your fuel/air ratio yourself. But you need a scanner (AutoTap, Ease, etc) to evaluate which way to adjust.

 

He is partly right..wideband is handy for tuning for sure but lots of people like me haven't the luxury of dyno within 500 plus miles of me.
So what do you do..well..if you have an autotap and maft you can lean the car out with the wot settings and they are instant in effect..the base takes longer..think 50 to 200 miles or something but you don't have to bother unhooking the computer although that might speed things up and its easy anyway.You get ltrims close on the autotap.most recommend slightly negative at part throttle accel..some look at differnt cells and average stuff..gets way complicated .I ignore idle
and decel and just look at part throttle accel.easy to do on my scanmaster.Then with base set you start playing with the wot..you can try a click or so leaner and drive car and watch knock retard.If you get no knock lean it a bit more..
Or you can go richer and richer and that will usually make the car noticeably more doggy and slower something that could be checked with a gtech or tazzo...watch the mph.You will then be very close to ideal.Of course with a full custom tune they can set idle speeds for cams,eliminate ses codes,play with timing curves and I think play with part throttle fuel and stuff maybe ..but for 500 bucks would probably just buy ls1 edit and do my own tuning.And maybe pay for the dyno a bit too here and there.

 

if i do change my mods he said he would charge like 100 bucks to retune everything again. i am not very knowledgable about ls1 edit and stuff like that. so i will probably have it tuned. so is that what i should do. and is that the best bet to get a dyno tune over using atap, and a maft. he said a maft is a worthless piece of junk. you have to constantly keep adjusting it. anyone out there let me use your atap for free around chicagoland? he said atap isnt good though for reading your a/f ratio is that true? thanks

 

If this guy is claiming a MAFT is a worthless piece of junk, you might consider a different shop. MAFT is great for dialing in to match the weather. I would definitely recommend one. I also agree with him though. MAFT only adjusts base and WOT ratios. LS1Edit will allow for tuning throughout the MAF frequencies and throttle conditions, which will yeild you better gas mileage and more power. If your not interesting in learning a ton about the cars PCM, or you don't have the time to log countless hours on your atap/efilive, yeah you're probably better to just let them tune it.

 

so i will gain alot more with a custom tune over using atap and a maft. these are my current mods. lid, borla, k and n, mac headers with offroad ypipe, ported maf, air temp module, zo6 clutch. i have seen no gains and my best et is 13.44 at 107.4 mph with out the headers and the new zo6 clutch. and when i got them on i lost mph (which means lost hp), and it was on a good day, i ran consistant 13.4's but never beat my old time. so how much would tuning shave off for me. is tuning a waste for me or should i just use the base a/f ratio that atap has and buy my maft. and if i do that (get the maft) will that only help a litlte bit???

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by jeff:
<strong>i just got off the phone with brian from bg performance and he told me that auto tapping and using a maft is not as accurate as getting a full tune. that i will have to keep on unplugging my battery because the computer tries to relearn itself.
1998 trans am ws6 M6</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">The part about the MAFT is bunk.
Since the MAFT is causing a change to AFR and the PCM uses Adaptive Learning it means you need to give the engine about 1 hour of engine drive time to allow the LTFTS time to fully adjust to the changes for part throttle.
No matter what they say about using a chassie dyno since the PCM allows LTFTs to have a 50% wide operating window no matter what you do on a dyno the PCM is going to do what it wants anyways and will readjust no matter if you use a dyno or not.
Just take the time, make a MAFT adjustment and do not make another change until the PCM has completed it's recal of fuel trims.
Make the drive time using different RPM ranges so that LTFTs get a balanced adjustment rather then just sitting idle would end up with different LTFT history.
It would be stupid to keep unplugging the battery for that just causes the PCM to have to east up process time redoing all the I/M 240 smog tests.

I used a MAFT for over 1 year and never once needed to use a chassie dyno, waste of money and time and was able to get perfect fuel trims.

Yes doing LS1edit is best path but even then a dyno is not needed, a good PCM scanner recording testruns does a better overall job of knowing what to tune and by how much.

 

If you tune the MAFT correctly then you should be able to set your fuel properly - and in a manner that doesn't require you to constantly reset the pcm. Your timing will fall where it will though - and will be effected by the maf tuning.

LS1 Edit is a better/more powerfull solution, but needs to be done correctly - I would reccomend it, but with a full part throttle drivability cycle before you put it on the dyno.

Chris

 

when i got my headers installed i didnt change my plugs and wires. its a 98 with 40k on it. should i do that. that is what speed inc. said to do and throw on a maft and set it -4 lean, and it should pick up considerably. does this sound right???

 

I have to agree that LS1 edit is a great tool for custom programming. I had mine tuned in primarily to eliminate some ses codes and set fans and shift points. I had the reputable shop also get my fuel curves and timings cells where I wanted them, BUT I still use my MAFT for fine tuning andit is an awesome tool when used with a scanning device. I have never had to readjust anything once they were set and learned by the PCM. The MAFT just alters the signal + or - that the PCM gets. Those that discredit the MAFT usually don't know how to use it, are discouraging the novice from playing dangerously with the O2s or are just trying to sell some custom tuning.Personally I don't think you can warrant LS1 edit with your mods and DO NOT make a MAFT adjustment until you have scanned the car and know what your O2s are. I am willing to bet you have seen no gains is because of the weather change since the first base comparison. I'm 3-4 10ths off my times from last February myself. Leaning the O2s will give good gains if you are rich and you can prevent KR. Tires and a converter will give excellent gains if you want imediate results. Good luck!

James

 

how much is ls1 edit. and how much will i need to know about it to use it. do i just install it into my labtop and plug it into my car??? like atap??? also where can i get ls1 edit cheapest??? so if i take the time to learn about ls1 edit, should i buy that instead of getting it tunned???

 

If you plan on spending more than 95% of your driving ON THE DYNO, then that is probably the best place to have it tuned.