Nabush

Guys,

Will be installing that soon on my 17 GS.

Won’t have the tuning right away...

Have some questions about that...driving the car with no tuning...to the shop.

First for me to clarify some stuff :

- CAI + intake Mani should flow better. More air = risk of running lean. BUT the MAF will see this air, so in my mind the ECU should take it in account.
- Long tube headers should help to evacuate exhaust gasses better, thus compensate the better intake air flow.
- the engine has knock sensors
- Does the LT1 look at O2 sensors at WOT ( closed loop all the time like Mazda Skyactiv) or it goes to open loop with predetermined tables ?

My point is do you think that there is any risks of driving like that 500 miles to the tuning shop ? With all the parameter I mentionned earlier I don’t see the engine running crazy lean to the point it would be dangerous for the engine, but perhaps I’m wrong....

I see a lot of people saying a tune is required right away, but do you have proof why and data showing the engine running bad with those simple bolt ons ?

I was thinking otherwise of doing a datalogging tune with RDP before doing my real tune on the dyno...

Thanks for your insight guys

Alex.

Internets_Ninja

Stay out of the throttle and you should be OK. The MAF is not scaled to adjust enough for the fuel needed for those mods. If you go WOT you risk running dangerously lean. So if you can trust yourself to drive it real easy for 500 miles then you should be fine.

Poppacapp

As said above.. drive as gentle as possible to the shop. No WOT stuff until tuned properly... and yes, your MAF transfer curve will have to be modified.

Nabush

Then Guys can you explain me these very good A/F without tuning on the C7 ? first baseline with CAI (426WHP) ARH headers no tuning (438WHP) , then ARH + MSD no tuning (459 RWHP)... A/F are the same all the way with no tuning....

Start around 7 min (baseline with CAI stock tune) 8 min (CAI/Headers stock tune) then MSD...



Seems to me stock ECU does a really good job keeping the A/F good without tuning... sure you can improve with a tune, but this shoes me than it works fine without tuning...

Internets_Ninja

Personally, I wouldn't feel comfortable with the 5500-6000 rpm range AFR. Look how the green line comes real close to 13:1 afr line. That's not much of a cushion for AFR that can change based on conditions. Could be okay though.

I also don't buy the plug wires thing. If anything they had a plug wire loose or one of them was bad.

GeorgeR_Zed06

Those cars come from the factory with a pretty hot tune (lots of timing). On my '14 Z51 A6 car, I installed TSP long tubes and off road X, KNN CAI, Brisk racing plugs - NO tune.

I drove the car around for a couple of weeks getting on it pretty hard. When I went in for a tune, All I gained was 3 hp and 3 tq, WTF?? The tuner said it was almost dead on except it was picking up a lil knock so he richened it up a lil and took some timing out of it. The car ran like a beast and had tons of torque down low!!!

Edit: Oh, and don't believe the hype about the Brisk Silver plugs, after a lil while my car lost power (2 tenths and 2 mph) at the track. Put the factory GM plugs back in gapped a lil closer and I was back in business. I could be wrong about this but i won't be doing that plug swap again....

Internets_Ninja

Your long term fuel trims surely made their way into WOT along with COT. This is by design but is certainly not optimal. Running too lean and knock retard is common with adding headers and no tune. Actually any mod you do that increases airflow causes it to run leaner. the LTFT's can make up for some of it but are NOT enough. With LTFT's rich and COT enabled you were probably still barely OK. This is why a tune is a SHOULD HAVE when you add headers. It's just way too close for comfort IMO.

There is also a lot more than goes into the tune than AFR. The AFE causes the intake temps to skew compared to the stock box and the IAT timing values/multipliers need adjusting. Not to mention the O2 sensor switching time when they are moved further away from the engine. Not to be a naysayer, but 3hp and 3tq is not common at all. No reputable tuner that I have ever seen has had those kind of results. Makes me think they didn't touch very much in the tune.

GeorgeR_Zed06

Yeah I always wondered myself why that is all I gained. My final numbers were 447 whp and 460 wtq thru the A6 which I thought was pretty good imo but wondered if there was more there...

Internets_Ninja

Unless you saw the dyno graph comparison, he could have been making stuff up.

Nabush

The shop in the video said they touched almost nothing when they tuned it, was doing 459 WHP with the Headers/MSD/AFE and no tune....


I don't say I won't do a tune, I should be fine the time I do my tuning... by safety I just bought a wideband O2 sensor to monitor that

Internets_Ninja

Nothing but the Air Fuel Ratio

GeorgeR_Zed06

Naturally Aspirated, I seriously doubt you will hurt that motor. Your knock sensors will pick up knock way before you even hear it rattling. Now if you had a power adder, then that would be a whole diff story.

Another thing you can do if you don't want to spend the money on a tune just yet or risk losing your warranty, throw a can of Torco or MS109 if your going to run it hard that way you don't lose too much timing. Also, you can throw in a 160 degree thermostat without programming for it and the ECM should burn a lil more fuel....

Nabush

With a blower I wouldn’t even run the car, I would trail it to the tuning shop
Money is not a problem, the good tuner is 300 miles away that’s all
About the 160 degree thermostat I’m not sure it is good to run the engine this low...what’s the point and who is using it and for what ?

Nabush

So guys,

Bought a wideband and finished my install today.

First, quite surprising, no CEL

The engine runs around 13.1-13.2 at WOT (2500Ft elevation where I live)

I think it's around what it should run considering it's a DI engine, but trying to get more informations...

The time I go to the tuner I'm considering buying a DiabloSport Intune 3 to adjust the A/F ratio....

Internets_Ninja

You should be running closer to 12.8 for a street car. 13.1-13.2 is too close to the edge IMO.

Poppacapp

What is wierd is mine seems to like, and made the most power in the 12.0 range(.85 lambda)

Internets_Ninja

Exactly.

There is little to no power to have being any leaner than 12.5-12.8 (around .90 lambada). I certainly wouldn't be running around in my street car leaner than that. Truth be told the most power is made by being richer (.85 lambada) as you approach peak torque. As soon as you pass peak torque and start increasing in Horsepower the mixture makes the most power around .90 lambada to red line.

This applies to N/A motors of course. And excludes any radical race purpose build engines that deviate from stock like combustion chambers and what not.

Nabush

I switched to Lambda on my wideband and did the calibration which I forgot to do yesterday

I run 0.88-0.89 Lambda which seems ok...With E10 fuel it mean 12.5 AFR...

I'll still add some fuel when Intune i3 will unlock my PCM (received it today but I need to be unlocked...)

godfrjas

I have a 2017 Grand Sport and the AFe CAI. It has two vent hose fittings, but the car only has one. I had this CAI on my 2016 and that year had two vent hoses and follows the install instructions to a tee. But AFe does not acknowledge this change and states that this CAI fits 2014-2018 - generically.
Did you have any issues? Did you see that the CAI has two fittings and you only have one hose?
Also, I need to put the 2017 intake on the 2016 Z51. Obviously that car has two vent hoses, and the intake only has one. But that is a different issue.

Nabush

You have to plug one of the vent hose...AFE supplies the plug. It is true 2017 version is a little different to previous ones on that aspect.