gymratt

iTrader: (3)

Without a dyno or track time yet, was wondering what would have better hp potential:going with 10% on the spark with +2-3%PE or 0% on spark but -2 on PE. Is it usually better to go with more timing or leaner PE? There was a post a while back that said 10%spark, -2PE gave the best hp increase. I saw as much as 4.0 KR at 0 PE, with 10% spark and -1.0PE, with 93shell gas, 60 degree weather. The only way I can get near 10%spark is if I am pig rich on the PE. Car felt real strong(at least for so few bolt-ons) at 0%spark, -2PE. TIA

BLK02WS6

iTrader: (2)

I think the only way to do it right is to get it on a wideband and get the A/F ratio set first - around 12.7 or so, and then see if it will take a little more timing without KR.

You are taking a big risk not knowing what A/F ratio your running. You might make good HP with it real lean - but you aren't going to do it long! And running it pig rich to compensate for too much timing is not good either.

It is entirely possible to be doing damage without hearing it or catching it on a scan tool. I know from experience and now have a very large credit card balance to prove it!

SuperSound99SS

its really car and climate dependent...i know my car w/ my FTRA kit picked up slight knock after i installed the canned tune...so i bumped up the PE and the knock is gone..goin to a dyno soon though so i can see if i squeeze anymore out of her....i've noticed my car runs at almost max spark adv right now...since mods that add 1 or 2 degrees gave me negative results on my last dyno visit

gymratt

iTrader: (3)

So I shouldn't trust any of the o2 readings, KR or timing readings of the Diablo diagnostic values? Are they really that inaccurate to trust for tuning purposes?

SuperSound99SS

the KR values are fine...the o2 readings are good for giving u a general feel for if ur runnin lean or rich...but shouldn't be trusted for proper tunning

koolrayz

iTrader: (26)

I agree I have the predator with a custom tune I have seen little corelation of the o2 sensors to what i see with the wideband on the dyno. Pay the money and tune your car on the dyno or your just chasing your tail.

y2kmaroonz

iTrader: (3)

I have the predator with a custom tune from Johan at Diablosport. 02's in the low 900's using the tool. I think he did a good job on my air fuel. If I go -1% on my PE I get knock. The KR and 02's go hand in hand. My air fuel may not be perfect but it has to be close if I lean it out a little and get KR.

koolrayz

iTrader: (26)

KR is an indication of a lean condition but not the final word. Just because the predator says .900 on the o2 sensors (and that SHOULD be a corrext A/F condition)Doesnt mean you are ok on the A/F. I whatched my O2 sensors like a hawk and thought i was ok, i went to the dyno used the wideband and in reality i was lean. i picked up 5 rwhp by tuning on the dyno with the wideband. A wide band is an expensive piece of equipment reading the O2 sensors on your predator isnt in the same league.

WJ SOM SS

iTrader: (11)

Anyone know what range the Predator "canned tune" puts you in? ('01-'02 F-bod). That's as far as air-fuel, spark advance are concerned....Thanks. WJ.

BLK02WS6

iTrader: (2)

I would recommend that anyone using a Predator go to a dyno with a wideband and find out what your A/F ratio is very soon! Let me tell you why I say this.

I had the Predator "canned tune" in my car with a Granatelli MAF - Granatelli's latest ad in GMHTP says "works with all chips & programmers, Granatelli/Diablo Predator recommended" - DO NOT BELIEVE THIS!!!

My LS1 was destroyed from detonation caused by this combination. I did not have audible detonation and everything seemed fine on the live data. You can not trust the live data. You can be lean and not know it.

The story gets even worse. I bought an LS6 long block and put in the car. I had Diablosport write me a custom tune. I put it in and everything seemed OK on the live data. I watched O2s like a hawk too. And there was very little KR - right before it would shift. I took the car to the dyno as soon as it was broken in to get wideband data.

Just started the first pull and it blew up on the dyno! I was absolutely sick

I have taken off the DS head so far, and it has detonation marks on the rear piston and a small chunk was broken out and made some nice marks in my new LS6 heads! There was never so much as a single ping out of the motor and KR never went much above 1 for more than a split second before shifts. O2s never below .905.

I am telling you - you can have serious problems, and you won't see it on the live data! Learn from my costly mistakes and go to a dyno.

As for me - I don't trust the Predator or their "custom tunes" any more and it is going in the trash! I will have my car professionally tuned with LS1 Edit when I get it rebuilt.

SuperSound99SS

im sry but i refuse to believe that detonation caused those problems...there was alot more goin on in ur motor besides detonation to cause it to blow that quickly.....detonation will not kill a motor that fast unles everyday u were goin to redline in every gear.....and the custom tunes are the exact same as gettin an LS1edit tune...maybe u had someone screw up ur tune but don't blame Diablosport

koolrayz

iTrader: (26)

I agree the problem was not the tune it was not checking the tuning on the dyno with a wideband.

BLK02WS6

iTrader: (2)

Well, that is where I was when it happened - on the dyno checking the tune with a wideband!! Kind of hard to do when you can't even get one pull in - it blew at 5,000 rpm! A/F was good at that point. Had to be timing.

BLK02WS6

iTrader: (2)

Well, you can refuse to believe it if you want to - but the marks all over the tops of my pistons don't lie!! And yes, detonation most certainly can kill a motor that fast when it is bad enough to remove pieces of your piston!!

Who am I supposed to blame? Diablosport sent me the tune, I loaded it directly into the car - noone screwed with anything from the base they sent me - and I went to the dyno -I never got the chance to change anything!

I didn't want to believe it either - but once I pulled the heads off and saw the evidence, what am I supposed to believe?? It was a brand new motor! If it wasn't the tuning causing that kind of detonation, someone tell me what it was.

Yes, the custom tunes are the same as LS1 Edit - if they are done correctly. All I'm saying is that I no longer trust getting something in an e-mail and loading it into my car. I will get someone with a proven track record, on the spot, on the dyno, programming my car - that is my opinion after my experience.

I was just trying to let others know what happened to me so you can be very careful. I don't want to see anyone else end up like this.