2000 GT tuning help

**Tonkin2000GT** · 12-09-2015

I was wondering if anyone knew what the best solution for a tune would be? I live in an area where there aren't really any places in general or ones I'd trust to tune it. I can only run on 93 octane because of the area I currently have a zzp tune with 0 KR. The car runs very well I just figured it could be better because every motor is different. There's a list of the major mods done in my signature.

**SgtMarshal** · 12-09-2015

if you have your own tuner like an hp tuner or dhp, will from overkill can take your scans and do some maf adjustments. he is a good tuner, but you must be patient when dealing with him, because it's not an instant process.

by the way, is the car top swapped? your signature says gen 3, but thread title says gt.

**Tonkin2000GT** · 12-09-2015

Okay how close can he get it that way without a dyno tune? Is it possible to gain a noticeable amount of hp? Yea it's top swapped I have zzp's ssm90 setup but with a SFI crank pulley 8 rib set up like a gtp. All I have are dual aeroforce gauges, autometer boost gauge, and a oil pressure gauge.

**Scottydoggs** · 12-09-2015

if by some miracle you have no KR on a zzp tune, just leave the tune alone.

**Tonkin2000GT** · 12-09-2015

Originally Posted by ScottyDoggs

if by some miracle you have no KR on a zzp tune, just leave the tune alone.

I've only had a blip of .8 and .6 a handful of times during wot but that was only on probably the hottest day of summer otherwise it runs at 0 all the time. How far can the tune be off if you have 0 kr?

**Scottydoggs** · 12-09-2015

honestly, thats nothing for kr really. id live with it. unless you want to play tuner and pull those little blips out, by either adding more fuel or taking a degree of timing out in the cells with the blips of kr. to do that your eyes will bleed reading up on how to tune.

a avt box for dhp runs about 250. after that its free to use, no credits to buy. hp will run you in the 500 range.

**SgtMarshal** · 12-10-2015

I wouldn't worry about that much kr. As far as getting the tune close, there is more than one way to tune a car. Overkill does it one way and ZZP does it another. if you want to see if the tune needs adjustments, you could monitor your long term fuel trims and see how close to 0 they are. from the factory, the goal is plus or minus 5% of 0. your other option would be to install a wideband and see what your actual afr is while doing a wot pull. from what I've read, you want it around 11.5, but on my car it has dropped into the 10's and most people say its ok.

learning to tune is a lot of work, and after learning what I know, I still prefer to have Overkill make adjustments for me with the HP Tuner.

**Tonkin2000GT** · 12-10-2015

Okay so I'm new to this what is a wideband? I have the dual aeroforce gauges I installed about a couple months ago. I still don't know what I'm looking for besides KR. I've heard about and read about the long term and short term fuel trim I monitor them I'm not really sure how to read them they fluctuate. Zzp told me to monitor air to fuel ratio they said should run in the low to mid 900's. I was assuming that's at wot? At wot I'm at about 920 with 0 KR they said it's good. I was wondering other opinions and I'd like to actually understand it better well how to read it anyways. Does the aeroforce gauge store data?

**SgtMarshal** · 12-10-2015

I've heard the aeroforce does data logging, but I haven't tried. I just use my hp tuner for that. What you are talking about with the air fuel ratio is the amount of fuel in your exhaust. From what I've read 920 to 930 on your narrowband O2 sensors is good for a supercharged car. The narrowband is pretty close, but is not as accurate as a wideband sensor. The stochiometric is the ratio of air to fuel in your exhaust. in a perfect world, when you are cruising down the highway, your air to fuel ratio will be 14.7:1. that means for every 14.7 parts of air, there will be one part of fuel. When you want to make power, that air fuel ratio is too lean, so something closer to 11.5 parts of air to one part of fuel is desired.

Your long term fuel trims are driven by your short term fuel trims. what happens is that your car's computer takes data from various sensors and either adds fuel to the engine or takes it away. in a perfect world, your fuel trims would be 0 all the time, but that is very difficult, if not impossible. you could monitor your short term fuel trims, but most people don't because the number fluctuates so much. the computer uses the short term fuel trims to calculate how much fuel to add or take away in the long term fuel trim. You also have a mode when the car goes into deceleration enleanment. when you are coasting down the hill at light throttle, your car will run very lean because there is no need for the typical fuel trim. any number that is positive in your fuel trim means your car is running lean, because fuel is being added. any number that is negative means your car is running rich because fuel is being cut.

**Tonkin2000GT** · 12-10-2015

Okay thanks that makes a little more sense do you think I should bother with a tuner at this point?

**SgtMarshal** · 12-10-2015

A custom tune is always going to be better, but it's probably fine the way it is

**Tonkin2000GT** · 12-10-2015

Yea but how much closer can you actually get it without a dyno tune?

**Scottydoggs** · 12-10-2015

you dont need a dyno at all. street tune is more real world.

**SgtMarshal** · 12-11-2015

the real usefulness of the dyno comes from knowing what rpm your car makes power, and how much power is made. that is stuff you don't really need because you can feel where your car makes power. another thing about a dyno is that all pulls are made in 3rd gear, and on the street, your car will rarely get to 3rd in a wot pull. almost all my pulls either start in 3 or 4 and then drop to 2 or start in 1 and shift to 2 at 45. the way my tune is set up I stay in 2nd gear all the way to 95.

**Tonkin2000GT** · 01-02-2016

So I just bought a used set of slp headers and someone put a o2 bung in it for a wideband but it looks like someone's first day welding... I was debating on if I would ever need a wideband to just have it cleaned up and rewelded or just cut it off and weld a plate over it thoughts? I have dual aeroforce gauges is a wideband necessary?

**BoostedPontiac** · 01-02-2016

http://zzperformance.com/3800/exhaust/o2-bung-plug.html

Use that until you get a wideband. That way you dont have to mess with it right now.

**Tonkin2000GT** · 01-02-2016

I have a o2 bung plug what I meant was either way I'm going to have it fixed it doesn't leak but it looks ghetto and that's not how I do things lol. I'm going to have a friend of mine fix it and tig weld it the right way I was just debating on just cutting it off and welding a plate on it since it's going to get welded on anyways. Is a wideband really that critical to have?