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Any experience with DiabloSport Tuners?

4 the ride

Active member
Joined
Dec 17, 2009
Messages
31
Location
Venice, Florida
Corvette
2015 Laguna Blue Z51
My 04 Z06 was modified back in 06 with a VaraRam ram air, Melrose long-tube headers, Random Technologies cats and a Corsa cat-back. It's been running great ever since (15,000 miles currently) until I decided to clean and inspect the air filter. Opened it up and wow! There's a quarter inch piece of foam for a filter. Decided I better improve this so I called VaraRam and they sent me an upgrade kit which included a new custom pleated and oiled element, supplied by "Green," and a new cover to accommodate the thicker filter. I installed it and it fit great. Off I went to test it out and by gosh it felt even stronger. Stick with me, this may test your knowledge base.

Since I'm from Michigan and was only wintering down in Florida, I shipped it back up north for the summer. This is important as it may figure into the problem. I picked it up from the shipper and filled up the tank at the local Costco. Ten minutes latter I had a "check engine" light. So, I'll now cut to the chase. It posts two codes P0171 and P0174 both indicate a "too lean" condition for banks one and two. I had everything check out and the tech concluded that it may be oil from the new filter (not a K&N but they dispute that their elements do this) or the mass airflow sensor may be faulty, doesn't check out that way but it could need replacing. He cleaned the sensor, cleared the codes and sent me on my way. 5 miles latter it's back. So, I call VarRam and the engineer there assures me that the problem is not with oil from their filter but rather it's from the engine now getting too much air. It seems that the new pleated and oiled filter flows 20% more air and in response to this the ECM is adding as much fuel as it can and posting a lean code. By the way, it seems that even though it is saying that it's way lean, it's really "rich." Go figure. The combination of the new air flow and the cool Michigan air has sent the ECM into a faults sense of reality.

So, what to do? The VarRam engineer suggested that I simply use a piece of duct tape and tape over the top half of the filter. I did this and it did make the car seem to run better but within 25 miles, the light was back again. @!#$% Next he tells me that the real fix is to purchase a "DiabloSport" tuner. This will provide a tune sufficient to solve my problem - but wait, there's more. I call Diablo and they tell me that their tunes probably won't solve my problem due to the effects of the headers. The recommend a fellow by the name of "Lew" at diablocustomtuning.com Turns out Lew has been doing these custom tunes for some time and they really work. So, for about $500 I can solve my problem and avail my self of increased performance.

I'm about 99% convinced that The DiabloSport "InTune" device purchased from Lew, with his custom tune in it is the way to go but I want to know what you think, particularly if you have ben down this road or have experience with Diablo Tuners.
 

Hib Halverson

Technical Writer for Internet & Print Media
Joined
Jan 10, 2001
Messages
13,453
Location
CenCoast CA
Corvette
71 04 12 19
Not sure if this thread is still active and, I don't know how I missed it previously, as, being a C5 Z owner, I stop into this forum every so often.

I can't speak to custom tuns by "Lew" but I can tell you that if you have headers and an air box, you're going to need a different calibration to get the engine to run right. So, whether you use "Lew's" cal out of a Diablosport or you send your engine computer to a place like PCM for Less, you must change the cal.

The idea that these air box guys make a product which changes the airflow into the engine so much that an aftermarket cal is required but, because they get too many complaints from people who don't understand the need for a better cal (in part because those folks don't want to spend more money), they artificially "restrict" their air box flow with a sponge filter just pisses me off.
 

4 the ride

Active member
Joined
Dec 17, 2009
Messages
31
Location
Venice, Florida
Corvette
2015 Laguna Blue Z51
I went with a dyno tune

Hib,

I ended up going with a custom dyno tune by an engine builder and tuner in "Nunica, MI." by the name of Baker Engineering. A young fellow by the name of TJ did the tune and I couldn't be happier. Turns out the engine was lean off idle to wide open where, amazingly, it wasn't too lean. At any rate I immediately noticed the difference, it runs much stronger at partial throttle - more linear acceleration. And, no more "check engine" lights. So, thanks for your input on this. I believe that Lew probably could have achieved nearly the same results but opted for this route.
 

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