10mm_

I recently added ARH mid-length headers and an AFE CAI to my 2015 Stingray, and wanted a tune that would take advantage of the increased airflow. I first tried the Diablo canned tune, which felt better but after talking to Diablo I knew I needed a custom tune. The Diablo canned tune does not add any fuel to compensate for the power the headers will add, and I also got a check engine light since I went catless.

I contacted Lew at Diablew tuning who is a super nice guy, he answered about 25 emails from me before I ever paid him for a tune. He sent my tune file within an hour after I Paypal'd him, he answered every question I had, and was overall very pleasant to work with. His tune felt even better at part throttle and driving around town than the canned Diablo tune, but I wanted to head back to the drag strip to find out how much faster the car was.

I will try to summarize my track experiences without being overly confusing/boring. I have been drag racing for a long time, I understand all to well how density altitude, traction, track prep, 60' times, coolant temps, gas quality / octane, oil temps, intake air temps, etc etc etc play a role in your 1/4 mile time and trap speed. You simply can't arbitrarily make a pass, change the tune, and go on a different day and make another one and compare the numbers unless you take everything into account. Which I did. The summary is as follows:

Intake and headers picked up about .3 and 3 mph in the 1/4 with the stock tune.

Adding the canned tune made the car no faster at all initially, after driving ~ 100 miles and the fuel trims had time to learn it went another .1 and 1 mph faster. I am not sure if the increase would have happened with the stock tune or not. The fuel trims function the same way so it is possible that after some time even with the stock tune it would have picked up the same amount, although I can't be sure. Diablo specifically told me they don't add any fuel at WOT so that makes me think that the fuel trims adding fuel and making it a little quicker would have happened even without the Diablo canned tune.

Adding the Diablew custom tune slowed the car down by about .1 and 1 mph, and also dropped my highway gas mileage by 6 mpg. The car also shifts erratically at varying RPM's and seems to lag more in between shifts at WOT. It never shifted 100% at the exact same RPM when it was stock, but the spread is bigger now and the delay is worse, as if the torque management is intervening. Diablew did not (and can not) make any changes to the transmission shifting so there is no good explanation for that behavior.

I asked Diablew for a refund and he declined, citing the policy on his website about no refunds. Which is understandable. He did send me another tune with some more adjustments, however the last time I sent him a data log he said the tune was good to go and required no more data logging or adjustment. So I have no idea why he would make further adjustments only after I proved that my car slowed down. I plan to just pay the money for a dyno tune, something I should have done in the first place.

I just wanted to make a thread so that everyone knew my experience, I'm sure there will be no shortage of people who will come along and say how they have had a stellar experience with Diablew. That is the nature of the aftermarket I suppose. I read all those testimonials before I bought his tune, but they all seem to be centered around "feel" and not dyno numbers or track numbers. (as a matter of fact the only dyno numbers I found would seem to mimic my resluts) If all you want is a tune that feels better, and trust me there is some value in that, then the Diablo might be for you. If you want a tune that actually increases HP (as they claim) and subsequently makes your car faster, in my humble opinion the Diablo / Diablew combo is not worth the $535. Most shops will dyno tune for that kinda money. The invisibility to the dealer thing was very appealing to me at first, but I would rather have a tune that works good and then is maybe invisible as a bonus.

Also remember that the direct injected LT1 is a different animal from cars in the past, the torque based ECU provides new challenges. I anticipate that some of the techniques used in the past don't work the same on this new car, and places that had room for improvement in the past may not have the same room now. That could explain why the Diablo worked so well in the past but maybe isn't the best option for a C7.

YMMV

Mike Campbell

Thanks for the input since I've been contemplating going with a Diablo canned tune but have been wary. I had an ESC tune with my C6 when I lived up in PA and those guys were great. However, if you had a problem I lived close enough to talk to them about it plus Doug knows what he's doing. Initially my C6 picked up .1 sec but lost a couple of mph. They told me then that the stock computer would adjust and after about 8/10 runs it would get better. I eventually went from 12.8's to 12.2's. But I really have doubts about any "canned" tune and I know the stock computer does adjust so you probably would have picked up anyway. One other thing is the LT1 is a different animal compared to my old LS2. I personally think the way to go is with a dyno tune. You're paying that much anyway. Good luck!

rcooper

Been a long time since I ran the 1/4 but I/we always had our tunes done by dyno. Canned tunes were just getting their foot in the door and it just did not make any since to spend money on an unknown at that time...seems to still be true today.
Go with the dyno tune, you will be much happier, and you can get adjustments if needed.

10mm_

I agree. If you actually want to be faster at the track it's the way to go. These canned tunes seem to be "feel good" tunes.


I'll report back track numbers after I get the Dyno tune done.

rcooper

Good luck, and happy dragging!

Vetteman Jack

Too bad you had the problems with the canned tune. Get the dyno tune and I'd bet your car runs much, much better. Good luck.

T/A KID

The E92 is a different animal..... Been tuning for years and this new computer logic is vastly more complicated.

To be honest there's not a lot of people out there that can actually tune these ECUs, a lot of them just "get by"

10mm_

I agree, even a lot of the shops I called couldn't answer simple questions about what they do.

I wonder if the Diablo itself is capable enough to handle the complex new ECU.

cobra502

10MM_, I'm sure you'll remember this one.

https://www.corvetteforum.com/forums...tune-dyno.html

Start with #9.

Like you, all I tried to do was give others the true story about email tuning. All I got from Mikey (Diablosport) and Lew was bad mouthing me about my incompetence, using a dyno to tune and changing the dyno results.

If Mikey could sell a dyno with his tuners, he'll probably love dynos. I can't tell you what a dyno and competent tuner has done for my C7.

But, Lew does seem to be a nice person.

All you have done is to confirm what I tried to show. Thanks.

.

robert miller

Man glad you posted this up on here. Let us know after your dyno tune & street tune on the car.

Like you have said here I wish I had my money back from all the azz hole so called tuners I have paid good money for doing a job that never made the car any better at all. Plus in most cases made it worse & lost a-lot og MPG also in the car.

10mm_

Yep I do remember that. After I made the passes to confirm this I remember thinking man....those guys at the Dyno were right.

I also had over 400 miles on the car with his tune and used Torco at the track (his first inclination was to blame it on bad gas).

There is a local shop called RPM that has tuned many supercharged C7's, I'm hoping I have the same experience as you after my Dyno appointment.

10mm_

I know the feeling. Just like I was told my mileage would be the same or better without DOD and I lost significant MPG on the highway.

My appointment is Nov 4, I'll have to take into account the lower DA but I'm hopeful for some good times.

robert miller

I have the trinity from them I also have 3 diff email from him telling me his tune will help the car much better plus I should r will get about 2 r 3 MPG more with his tune in the car.

I am glad you did do this post but then again really dont know who to have tune my car. I may just wait until I put the small blower on the car this winter. I only have headers mid pipe & cold air box on the car at the moment.

But like you were talking above funny when you talk with these tuners they ever one say yes can do it will stand behind it 100% but after getting your money. Then you are the crazy one that dont know shi* & it is all in your head what you think the car is doing.

I was going to email him this weekend & pay him for a new tune from him. The only thing I didnt like in the email I ask him to call me r I would call him. He email me back & said he NEVER ever gave out his number to no one. He did everything by email..

10mm_

He told me the same thing so that he had a paper trail of all conversations.

NinjamanZ51

Moral of this story? Wait until more solid tuning solutions are available. I'll wait until there's something like Mast Motorsports custom PCM before I start to tune anything substantial.

MikeLsx

There are probably a handful of people who can nail a C7 tune.

For now we are going to see a learning process from tuners.

10mm_

I sure hope RPM is one of them lol

10mm_

Would an AEM or Halltech work?

10mm_

Car picked up .3 and 3 mph from the dyno tune

RFBHD

Why are you wasting your money???? This car is set up for peak performance when it comes off the line. All you are doing is blowing your warranty. If you talk to an honest performance shop like I did and was told do not bother with any of this small stuff the only option with a real payback in rwhp is a blower..end of story.... so if you don"t care about your warranty... go big or go home