O2 sensor is not the problem. He was getting those readings (on the graph) from his own sensor at the end of the tailpipe. Tuner swore that it'd be accurate even with the cat. Fact is, even if the sensor is off, there's still a problem with fueling. You can feel it in the car, and you can see it in the fuel trims. Moving the sensor will do nothing to fix the underlying problem.

Doug, as for the plugs, that's an easy 5 minute swap. The hard part will be organizing a time where we can make it to the dyno with Brian there as well. Brian seems to not really care about working on your car. I say, just let us rewrite the tune from scratch. I can get the injector table done in no time.






As for the noob... launching is a skill. It's part of racing. Just like cornering is too... that's why people love autocrossing and road courses. It tests a variety of skills. Roll racing is pretty much "who has more power?" Tell me... how is comparing power racing? Isn't racing supposed to be a competition? Doesn't competition usually require skill?

I could spend $10k building up my car to be more powerful than yours... or I could spend hours behind the wheel learning how to drive my car better. Which one sounds more respectable to you?

 

So the lean spike HAS to be tuning, not flow rates. How are you all sensing boost for enrichment? One of the advantages of the SMT-6 is it has its own MAP sensor and adjusts fuel based on boost pressure. Are you using the eixsting MAP to tune the fuel curve for boost?

 

Its tuning, the car won't come out of closed loop. I have two scanner files to show this, but I don't have anywhere to host them for you guys. I would have fixed it that night, but the PCM was locked.

 

Good luck with the tuning man, nice to see you are almost done the turbo project....

markiebredsrt4 : I like both types of trannys but I think someone asked you to explain why a standard would be better than a auto? Just wondering if you had an anwser?? I love my 5spd in my car, its funner to drive and I like shifting. But a well built auto has many advantages over a standard.... So many people are uninformed about how autos work and how much better they are.....

 

Well flow rate isn't the problem... but one possible theory was fuel pressure. I've heard of the fuel pressure regulator lagging behind in some boosted setups and therefore fuel pressure dropping momentarily when going into boost. I know nothing about the fuel pump and fuel system on this car aside from the injectors and rail.

 

well, i emailed brian to see if he knew it was locked or not and if there is anything we can do to unlock it in the mean time, im not sure how locks work, like is there a password he can give you or something like that?


well i think you guys probably will get to do this but i wanna give him one more chance to redeem himself as a tuner, even after that, i might still want you guys to look more into it to see if it can be tuned better.

 

In the log I have, if I remember right (its on the laptop in the car) at 100% throttle, MAP at ceiling, don't remember the RPM, the short term fuel trim is still trying to correct (~-30%). If it was in open loop, STFT would be 0.

No, it might not even be locked, just unreadable by a different tuning software. Thats not supposed to be how it works, but who knows with a newer PCM. If it was locked with a password, I would need the same software to unlock it.

 

Hmmm...a distinct possibility, especially with those large injectors. While I'm not totally convinced the SMT-6 with an additional injector is ideal (we'll see - that's what mine will have) I am beginning to see the rationale behind it based on these issues. Keeping the stock injectors avoids these issues, and using the 5th injector for boost enrichment has advantages.

 

Injectors are flow rated at 45psi. Our fuel pressure is 60psi, thus increasing their actual flow rate in our motors. 60/45 = 1.33 * 45 = 56lb flow rate at 60psi fuel pressure.

 

yeah that sounds about right from ehat he said lol im clueless on some of this stuff.

well hopefully we can see what happens. he agreed it should be able to be read by hp tuners but i guess it hasnt been tried yet to know for sure, but if he says its not locked then i guess thats our answer.

 

God so much garbage in this thread

whoever said 13.9is idle afr..wrong ideal idle afr is 14.7...that is why narrowband sensors have their vertical asymptote right at 14.7 so they can measure the voltage flops to get 14.7 right on. Wide open on a turbo car is roughly 11.5-12.0:1 at 10.0 ur leaving a lot of hp on the table and possibly drowning the spark.

I dont see why ud need to move the o2 sensor. Its used under part throttle conditions where heat is relavitely low. Wide open its not even used.

Get the tuner to flash it back to stock..If hes being douchey about it just get another stock ecm www.car-part.com i know it sucks having to buy another but it might be the only way. Either way request ur money back from the tuner and dont pay him a cent. Just from what i hear I dont trust him at all.

If you can get it to read and write on hpt by the 20th ill be in town that weekend finishing my car im sure we can do a 2 for 1 tuning weekend bonaza to get both of our cars running.

Dan

 

Yay! Dan finally steps in.

 

so if this is true why do we modifly ours cars to make more hp. using your logic wouldn't the smartest thing to do would be to ride around on slicks with a full drag suspension right...

and how is roll racing not a competition... you still have to shift don't you

and when the trq overwhelms the tires there is only so much you can do

and yea launching is a skill meant for the dragstrip...wanna talk about rice running from a redlight on a street is pretty ricey to me but going from a 50 on a bare interstate diff story

we have fwd cars why would you cater to you own disadvantage,.. this convo is starting to get old to me honestly.. im tired of arguing about this


and for the tranny convo my bad i didnt know this car was gonna be a 60 ft champ at the strip

and to me a true sports car should always have a stick..mates the driver with the car

a cobalt is a sports car right...or is it?

and 9 times out of 10 a full out drag car is gonna have a auto just because it can shift faster


ever wonder why a c6 z06 doesn't have an auto....

 

I never said HP wasn't necessary at all. There has to be a balance between power and skill. That's what makes things fun. That's why there are classes at any sanctioned race.



That's all the skill required... mash the pedal, shift, and steer straight. There's no controlling your throttle off the line, tuning the car so you can get a decent launch, etc.



Like control your throttle???



Wait... so street racing is ricey if you're doing it from a redlight, but not if you're on an open highway going from a 50 roll? Wow. I'm so glad you could fill me in on the rice-ness of street racing.



By that same line of thought... why not cater to your advantages and race a course with some bends? These cars are light and easily modded to handle a lot better. You know who had trouble at the last autocross I was at? A Vette and an LS2 GTO. They couldn't control their power through the course. Tell me now that power is all that matters...



A Cobalt is not a sports car. A Cobalt, LT LS SS or SS/SC, is a sport compact.



Your point?



Nope, never wondered. Most people that buy a C6 Z06 don't buy it as a daily driver. They buy it as a sports car to have fun in. Again... the auto is better in this case cause it's a daily driver. How many times do you want to overlook that? You're playing a broken record.

 

With new age transmissions, and the fact that you can tune a automatic transmission, it is possible to be faster than the same car, with a stick.

And I will openly express my opinions. Drag racing doesnt take much skill at all...

and roll racing is still considered racing, and you still get a kick out of it...but like Ppazz said, its really only who has more hp/tq & how heavy your car is.

Road Racing/AutoX is more of a competition.

You can have a 4,000lb car with 400hp/tq, and lose to a 200hp/tq 2,700lb car...

Granted, HP/TQ is nice. We all bought our cars for our reasons. We all mod our cars(perf. mods) to make it faster, but there is a point where too much power will hurt you.

In Drag Racing, you have a 1,100hp V8...but your on street tires....you'll spin them tires like nobodys business.

In Road Racing/AutoX, you have a 1,100hp V8...and your suspension sucks....you'll be fast as hell on the straights.....but extremely slow on the turns...


different ways of racing, require different mods, and is only fun for different things.

If i had a 1,400hp I4....and i did nothing but spin my tires in every sort of race, and the only way i could get grip is drag slicks.......it wouldnt be fun.

Id be happy as hell to get approx 300-500hp out of this car....i wouldnt go any higher.

500hp is a long shot as of now, but it all depends...I do drag racing and the occasional road racing, but i mainly toy around on the streets.

 

Amen brother. I feel your pain.

 

I agree Dano, Al and the pose here can tune your car Doug. You need to install the plugs and research the thread I posted on plug gapping (.30) and call that guy Rhys who has tuned a few 2.4s to see how to Call 'em up an ask 50 questions on tuning the MAF and how you can enable PE values and open loop AND GIVE THE INFO TO DAN and AL . CALL 'EM!!! they've tuned a few Solstices on HP Tuners.

 

So do I, Celicacobalt. It also makes me nervous about mine going in the shop this week....

 

Also realize whats hanging up anyone other than the tuning shop from fixing the car is that it doesnt have a wideband uego installed. Until then hes pretty much at the mercy of the shop with the dyno.

 

damn, i forgot that we wouldnt be able to do much tuning without a wideband installed. So, the only place we can tune is on the dyno but we can still tune it.

ill be talking to them for sure to figure this all out.

 

good news, the shop just called me and they found the missing tuning tables they needed and as soon as the tuner gets back in state we will go back for the final dyno tune and hopefully get this all cleared up.

 

What tables did they find???

 

the only i can know for sure is the tps table they needed and he said there were more but i was talking to ed, brian is supposed to email me later to give me more details. i just have to get my car up there 1 day before tuning to lower my boost to 8 and drop in the new plugz, im gonna try and keep the o2 sensor in stock position for now until for sure needed to move

 

I was just about to say, I bet it was the TPS table for PE. You're in boost at less than 40% throttle. They should set it to 0% TPS and base it solely on MAP. ie you go into PE when MAP exceeds 90kpa. just my opinion. However, that doesn't explain why you went lean on the dyno.

 

Like i said...u shouldnt have to move the o2 sensor at all since it isnt even referenced under wot and ur part throttle temps shouldnt be any different from when u didnt have turbo