massconfusion

iTrader: (18)

i had my car dynotuned last year for my bolt-ons. For a curious reason their is a 50 hp dip as well as torque between 4500-5000 rpm roughly. I did bring that to the shops attention and they said it was when they shifted the car. Well after driving it their really is a big dip that is somewhat noticeable. I know your all thinking i should make them fix it and i would except they went out of business. They worked on mostly fords but did good work on my buddys corvette. Just wondering if your guys think it is the tune or the fact that i don't have o2 sensors right now. Should i try o2 simulators or not worry about those at all and put my heads and cam in and go to speed inc. or can anyone tell me who does mail order tunes with sct excal 2

JonCR96Z

iTrader: (33)

Mass confusion, huh?

It's hard to say anything about the tune, but which O2s are you talking about. You don't need the rear ones at all. It won't effect the tune or power in any way.

If you don't have front ones, then that may be part of your problem.

ss346ci

It could be the tune. That sound like a knock sensor that is picking something up and pulling timing. It could also be that they added timing to a certain rpm range forgot to add those degrees to 4500-5500. As in the last reply no front o2s could hurt you. the engine will stay in open loop and the fuel trim will be out of whack versus what you actually need.

massconfusion

iTrader: (18)

thanks that helps alot. they said they did add timing so i'm sure they did something stupid like forgetting to add to the rest. Should i just add two o2 simulators to the front or should i weld in two mounting holes in the front and add the 02 sensors in to my headers? thanks for the help.

JonCR96Z

iTrader: (33)

The front O2s either have to be there or have to be tuned out in the PCM, they don't make simms for the fronts.

jrpimp00

iTrader: (17)

So you have no 02's at all? Im confused

massconfusion

iTrader: (18)

ok here it the complete story for this. I bought the car last summer with just headers and an slp airbox. car is also an m6. car ran good and hard until i added weiand aluminum intake and fast90mm tb. The car was running super lean and i got it tuned and then i saw the dyno sheet. max of 323rwhp and i think 344rwtq. not bad for 90,000 miles right. then while i was talking to the tuner i showed him the dip and he said it was from when he shifted. I thought oh ok like a tard cause i never had gotten a dyno tune before with my talon just street tunes with a wideband o2. anyway when i got the car i noticed it didn't have any o2 and i asked the tuner about and he said it shouldn't matter. key being shouldn't . anyway i will pick up a set of widebands for the front. So bear in mind i do not have o2s with my bolt ons. I didn't ask for them to be tuned out ethier so as far as i know the car is in open loop. I'm going to say this is having an ill effect as well as the poor tuning. when i do my heads and cam this week the car will be tuned at speed inc cause they know their ****. any opinions or thoughts on any of that

JonCR96Z

iTrader: (33)

You just need one wideband. Get that and you'll be well on your way,

massconfusion

iTrader: (18)

oh really i feel dumb. i just use it for data logging then right. i would just put it in the y pipe right. sorry for all questions i just want to make sure i know what to buy and how to hook it all up. i just don't want to keep ordering parts over and over. thanks

massconfusion

iTrader: (18)

after some thinkin' i just figured that if i'm going to buy software then i don't need to buy o2 sensors because i can just tune it out with hp tuners or do you guys still recommend using o2 sensors anyway. As it stands currently will be buying the lm1 wideband and hptuners pro. does this sound like a good tuning setup especially for a rookie and is their anything else i should buy? kind of excited and scared because i'm about to start learning/obsessing something new with my car. lol. thanks for the help guys

JonCR96Z

iTrader: (33)

You can put the wideband O2 sensor anywhere you want, but the closer to the engine the better. Best place is one of the bungs for the factory front sensors.

Here's the thing about having no O2 sensors. It's perfectly fine to go without them, as long as the tune is right. So put the wideband in get the AFR close in all areas and you're good. The downside is if the weather changes much the tune will be off again.

I run my car in open loop speed density (no O2s, no MAF) all of the time. And I usually keep the wideband in at most of the time as well. During the winter, sometimes it would be a little rich and other it would be a little lean. Not enough either way to warrant a change in the tune though, but now that its starting to get pretty hot some days, I've notice that it's a bit on the lean side. A few minutes of logging and tuning and I'm back to normal.

If you drive the car a lot, it would probably be easier for you just to eventually stick some O2s back in the fronts, but it's not really necessary for right now. You can't use them while your tuning anyway and they're expensive as hell.

massconfusion

iTrader: (18)

yeah thanks. I only drive in the summer thats why i'm starting to throw money and parts at her left and right. I think i'll just leave the o2's gone and just save the money. ordering the tuning stuff today or tomorrow pending a sale with my old parts. for the hp tuners and the wideband its going to be close to 900$ or two trips for a tune at speed inc in my case