2008 LS3 A6

As you all know, i live in the wonderfully HORRIBLE state of Califlunkia.
I just got me some headers, its been about 3 years and i finally decided to pull the trigger. So i bought Texas Speed long tube headers with off-road x pipe. Hoooray!!!
BUUUUUUT... I have to do a smog on my car every 2 years. In fact my next smog is in less then a year. These headers are probably the only mod my base c6 will ever see so I have been looking for a tune so i can clear all those 02 codes.

I talked to Lew at DiablewTune.com. He is a vendor here. He does custom tunes for cutomers using Diablosport tuners. Tunes for cars with minimum mods.
So I sent him an email telling him that I will have to remove my (theyre actually good quality) horrible slip on style headers every time I have to do a smog test on my car. And that I need a tune I can turn on or off every time i do a smog test without headers, then i could put the tune back on when my headers are reinstalled on my car.

He has a very generous price and kit for his tunes and I think they would fit my case perfectly fine.
NOW, he claims that with his tune I don't even have to remove my headers anymore and my car should pass smog. This is WITH his tune. He says he has done thousands of people in California and Corvettes as well. Im having a hard time believing my car will pass a smog test with his tune, while i have long tube headers with an offroad x-pipe. Lew says he has never heard of anyone having to take their headers off and and go back to stocck tune just to pass smog, he says his tune will take care of it all. IDK i'm skeptical...

I have read everywhere about Lew and his service, they all have good reviews and nothing but good stuff coming from Lew. But that their cars only FEEL faster when they actually arent, and they actually perform worst (yet they feel faster)

Here is a thread about it: https://www.corvetteforum.com/forums...ew-tune-s.html

I know we are talking about a 2008 LS3 for my car and LS motors have been around for a while... yet in that post is for a c7 LT1 when they were still fairly new. So i'm not sure what to think.

i cant afford to get an hptuners tune from a shop 2 1/2 hours away every time i have to do smog. At the same time i'm not trackiing my car, but i don't want my car to perform less then stock with headers installed. i still do very spirited driving and do small races with a few people here and there.
what do you guys think?

 

It will depend on the smog technician's ability to spot headers during the visual inspection. If spotted, you will fail.
Also, make sure the emissions recall for year 2008 was completed and record of completion was sent to DMV. Incomplete emissions recall will fail your test. You can look this up using recalls by VIN, www.nhtsa.gov

If you decide to install/remove the headers at the time of each bi-annual smog inspections, the DiabloSport would be a good tool to flash back and forth tunes according to the exhaust set up. Another option is to run Z06 exhaust manifolds, down cat pipes, mid pipe and tie it into the existing mufflers or Z06 mufflers and not worry about passing smog. Make sure your emissions recall is completed before you do anything, otherwise you will be doing it twice.

As far as DiabloSport tunes, in CA we have 91 octane and the tune for 91 octane will have a little less timing vs 93 octane Diablo tune. So performance will vary depending on tune used.

What you will feel in most tunes is the reduction or elimination torque management which will maximum power delivery below 3000 rpm in every gear. Also, the fuel trims will be tweaked and A/F ratio will be adjusted which will both allow the car to run a little more responsive. The cooling fan will come in a little sooner along with other little tweaks, i.e. auto trans, COT's, timing adder tables, etc.. The addition of headers and CAI will benefit from Diablew custom tune to further increase the responsiveness and take advantage of additional horsepower/torque.

Before I had a S/C installed at A&A Corvettes, I had a Halltech MF103 air intake and a Diablew custom tune. My car always ran strong, but with Lew's tune the car felt more responsive thru the power band in every gear. BTW: My car is a 2008 LS3, Z51, NPP, 6sp. Manual. Prior to the S/C install, we wanted to save a copy of the oem tune I had in the married DiabloSport handheld tuner. So, I asked to do a back to back dyno run with the installed Diablew tune and a dyno run with the oem tune. As I mentioned, the Diablew custom tune felt more responsive and quicker than the oem tune. However, with the Diablew tune HP was up only a few numbers and torque was down 2 ft-lb. compared to the oem tune. Keep in mind, I live in CA and use 91 octane. I would expect a little better results with 93 octane/ tune and bit more timing. So, with the Diablew custom tune, it wasn't how much increase in power, but how the delivery of power felt more responsive thru the power band when compared to the oem tune. Would I do it again, absolutely!

 

Just went to that link you provided and checked recalls for my VIN. I have no unrepaired recalls so I am good to go. Didnt know 2008 had an emissions recall. I did do a recall for headlights not working anymore at night. All solved.
My car is a fully loaded leather wrapped 4LT with NPP and HUD.
I am freinds with my smogger but says he cant simply cheat the system how he could back in the day. I'm wondering whether he sees the headers or not if my car will pass smog. He has a 9 second twin turbo charged Camaro so... (not that it has anything to do with my car)
Not sure if my car will pass with diablewtune and headers with offroad xpipe.
That in itself is worth the investment for diablewtune if I dont have to remove them.

 

You'd have better luck with a catted x pipe and with an NA ls3 you won;t lose any power with good cats anyway.

 

If you never go racing to see timed results, a "feel good" tune is fine. It's the same as the sugar pill placebo that cures cancer. There's also an East coast equivalent in NY.
If you get the HP Tuner dyno tune you mentioned, buy the system and download your stock tune first. Then let the dyno tuner use your system (saves you $100-125 for the license fee, aka credits), which gives you the control to swap them back and forth yourself. You can make your own mods to the tune or let anyone else you trust to make changes.

I've heard that leaving a really dark pair of sunglasses under the hood with a $20 bill clipped to it has helped pass some inspections.

 

No experience with diablo, but from what he is saying, the tune is not the issue. As long as you can get by the visual, you should pass.

 

I have an 08 base like yours with Headers no cats, Cai and with the Diablew 93 Tune it passed smog hear in Texas. What Mike3 said is dead on. It will need to pass the visual inspection and it will need the recall completed which requires Two additional CATS for a total of four in Comiefornia! Lew is legit! I have since upgraded to a custom tune and yes, it still passes smog.

So if you can get passed the four cats and the visual, you might be good.

 

California requires the addition of 2 more cats making a total of 4. You will not be able to register the car without meeting this new requirement. GM put out a program for free replacing the existing cats and adding 2 more further down the line. It isn't mandatory but California says it is to register the car. Smog guys know this and will check for additional cats. Not so easy anymore with big fines. They do not test the tail pipe unless the car is older. System readiness via OBD and visual. So you are likely stuck until you get mandated upgrade.

Plus long tubes are illegal anyway for road use regardless of tune.

 

I have had two smog inspections after the completed emissions recall and not once did they look for additional cats at the mid pipe.

 

On my last amog on this car (or any car as a matter of fact even the 95 vette) no one ever checked under the car or pays attention to the engine bay area. I hope that's the case with my next smog. I might have a cam to go along with my headers if I decide to do it next week or whatever. Might as well pull the trigger on that as well if I'm going to get a tune. Supposedly hptuners tune from the shop will pass the cars.

The only thing they check is codes on the cars and visual inspection for blue or black smoke.

Either way, I'll make sure I have my NPP fuse on to keep them closed. Here's to hoping I pass on my next smog. If I get a cam it would be a stage 1 or stage 2 Texas speed cam kit.

Shop is American Heritage Performance in Los Angeles.

 

You may find someone who may try to pass a visual smog test, but unless the Ca DMV has received notice from a GM certified shop stating that your car has the new mandatory mid-pipe with the two new additional cats, DMV will not allow an '08 Corvette to pass. Your car may not have been in California at the time, but a few years back the local California GM Dealers received these new catted mid pipes from Detroit, installed them on California cars and notified DMV that these cars have been updated. From that point forward, computers at all California smog stations immediately accepted or rejected any '08 Corvette that has attempted to pass smog. All this is now dependent on their computer system showing if a car has been updated or not. A smog inspector does not need to look under the car to see if the four cats are there. The computer knows all. How do I know? I went through this on my '08 LS3. My car has now passed smog the last couple of times. But guess what? I won't explain how I got around all this on the web, yet I have a brand new OEM catted mid-pipe in my garage that was never installed. Let me know if you need this.

 

I checked my VIN on the link provided on an earlier post to check about that and there is nothing missing from my car. The next smog will be the 3rd smog my car will have here in California since I owned the car. No problems passing at all.

Here I thought a tune would trick a smog to thinking it has cats. Since there are no codes or anything and the car just thinks it has its cats... I just dont get it.

 

I've passed the smog test several time here in California with only 2 cats on my 08Z.

 

As of now, the smog test does not know what tune you have as long as you satisfy the readiness codes complete and any emissions recall complete. In CA, the evap readiness code and only the evap code can be incomplete and still pass.

Since, your VIN showed no open recalls you should be good, as long as your readiness codes are complete.

As far as the visual, it will depend on how observant the smog tech is. I have had encountered some strict techs. One who used a mirror with an extension to look under my oem work truck's exhaust. This only happened once with my 2013 Silverado work truck. Stayed away from that shop.

On my 2008 corvette, one tech attempted to measure my aftermarket ATI HB. The ATI HB was stock size and the CARB certified supercharger made access difficult to measure However, I removed the M.M. catch can because that will fail my car. So far, I am 3 for 3 passing CA smog testing.

Knowing the shop tech or how strict the tech is very helpful in choosing where to go. Good luck on your test!

 

A correctly folded $20 will usually get the job done as well. Works in Vegas for room upgrades also!!!

 

Just got back last night from Mesquite Nevada which is like 5 minutes from Arizona and Utah as well. Visited 3 states this weekend. Was fun. My uncle lives in Mesquite so I had my headers shipped over there. Going to install them hopefully this week. Gonna try to work with the shop and see if a cam is in the works. Maybe, maybe not.

These Are Texas Speed LT Headers 1 7/8 with offroad x-pipe. 3 inch inlet and 2.5 inch outlet to fit my stock NPP.
$750 can't beat it. It's a slip on style and not flange... but the quality is top notch I'm suprised! Will see how fitment goes. I also have Bilstien B6 HD shocks ready to be installed. Excited to do all the work!