mds pulse

Post by **mikel** » Wed Nov 14, 2007 12:10 pm

It is something we will need to see in person, as tuning these types of things out can be very tough without a car to use for testing.

Thanks

bremo76 · Post by **bremo76** » Wed Nov 14, 2007 10:00 pm

mikel wrote:It is something we will need to see in person, as tuning these types of things out can be very tough without a car to use for testing.

Thanks

Where are you located. I am in Va. I could have a car. But, reguardless of that, we paid for a product that was supposed to work, but now we got this surge.

Post by **mikel** » Thu Nov 15, 2007 12:15 pm

The tool works, no question.
I have over 1000 super happy customers that let me know that daily.

We will look into this as soon as we get a vehicle in the shop that is experiencing this issue.
Have you considered turning the MDS off?
I'd be willing to bet you will see no loss in mileage with the tune installed....

Thanks

KWhale · Post by **KWhale** » Thu Nov 15, 2007 6:20 pm

Mike, I would offer mine (actually the wife's daily driver) in a minute if we were near to each other. I don't think it will be hard to find a car that has the issue though. It's seems that tons of the 5.7s have the issue. Maybe the next time you have one in for tuning, check it for the pulse or push we're talking about. The odds are good that it will have the problem too.

I don't know about turning MDS off. 91 oct gas here is about $4.50 a gallon. I guess I could run a few tanks through her to see what kind of mileage drop I get. My driving is almost all highway, so I'm betting it does go down a fair bit though.

Thanks for responding Mike, and if you do notice the problem on a customer car you're working on, and decide you can fix it, please post here to let us know that a fix is somewhere down the road??

Post by **mikel** » Thu Nov 15, 2007 6:51 pm

$4.50 a gallon?
Wow.

Well, I have seen a few guys disable MDS and report no loss of mileage, and we have been disabling DOD or AFM (call it what you will) on GM applications for a while, and the proper tuning always makes up for whatever 'gains' were there from disabling the 4 cylinders.
Give it a shot, and we will look into this for sure.

Thanks

XERyder · Post by **XERyder** » Fri Nov 16, 2007 1:08 pm

I also have this effect on my Charger, and I think it may be in part to the added timing we run in our tunes. I accept the fact that the further I get away from a stock tune the harder it is for my car to make a smooth transition from hitting on 4 to all 8 cylinders again.

I think that the canned tunes are great, but head over to one of Diablosports tuners to really see how much better your car and mod combo can get. With the narrow band oxygen sensors we have on our cars, neither we nor the PCM have any idea what mixture we are Really running.

Put all the bolt-ons you want on your car and then go get tuned, you will be able to disable MDS, have even more power and likely see a small increase in mpg - you surely won't lower mpg with MDS disable after a custom tune. It is so well worth it - trust me!

plcman · Post by **plcman** » Sun Nov 18, 2007 3:17 am

My 06 Charger R/T R&T does this MDS pulse moving the trans to 5th stops the surge. I will try the mds delete and see the results in fuel milage. I'm in Jacksonville, FL. How far to your place?

bremo76 · Post by **bremo76** » Fri Nov 23, 2007 10:41 pm

Can some one please tell me how to turn MDS off on my Charger with my Preadator?

ikonis · Post by **ikonis** » Wed Nov 28, 2007 6:40 pm

As I stated in another thread, I too experienced the huge surge with the 91 tune with mds on. I turned it off this morning then drove to Dallas (approx 100 miles, all highway). My milage was/is HORRIBLE now that mds is disabled. The evic is reporting 15.3 mpg. I also used 1/2 a tank of gas as apposed to the normal 1/4 tank.

Edit: forgot to mention I drive an 05 magnum rt. The only current mod is this predator tune.

alex3dworld · Post by **alex3dworld** » Wed Dec 05, 2007 10:26 am

i think every car also is diferent, mine for example used to stall a lot, i have actualy the record of stalls four in 4k miles. after diablo (only two weeks ago) no more stalls with the 91 octane cai and egr off. so my experience so far is 100% positive.

rotrhed · Post by **rotrhed** » Fri Dec 07, 2007 10:16 pm

I've had the MDS off for two weeks now and the surge is gone.

I drive the same 100 miles roundtrip every day, same conditions, same traffic. I drive my car other than my commute a bit, but not much.

My car consistently registered between 19.5 and 20 mph prior to MDS off.

Past two weeks I am consistently between 17.5 and 18 mph... about 10% less. Not good, but better than head-bobbing all the way to work

You guys need to fix this in an update. You know it is the mds switching between 4 and 8 cyls... why do you need to "see it"? Way to many people on multiple forums are seeing this...

KWhale · Post by **KWhale** » Mon Feb 11, 2008 4:31 pm

Mike;
I finally had a chance to do a little testing of the MDS off setting. Again, I run about 80kms per day on the highway, and about 20 kms per day in traffic. I've tracked my fuel usage since day 1 of owning the car (it was new) and after 35,000 kms, without the Predator tune, I get 22.2 mpg pretty steadily. With the Predator tune, and the annoying MDS pulsing, over 8 tanks of fuel I was up to 23.8 MPT. Using the same octane fuel from the same source, I ran 3 tanks through with MDS disabled. While it was nice not to hear that MDS kicking on and off and pushing the car forward every minute, I can tell you for a fact that my fuel mileage is down.

Stock tune = 22.2 mpg
Predator 91 CAI Tune, no adjustments = 23.8 mpg
Predator 91 CAI Tune, MDS Off, no other adjustments = 19.3 mpg

So it's pretty clear to me that the MDS does save you fuel on the highway, and it's an option I would like to have enabled when I'm running the Predator tumes. So now the question is, have you had any cars in the shop that you were able to check for this problem? If so, is there any news? If not, are you even planning to look at this annoying problem that a lot of people seem to hate?

Any update will be appreciated Mike! Thanks eh

johan · Post by **johan** » Mon Feb 11, 2008 4:40 pm

If anyone is willing to send me their current tune i can take a stab at this and see what i think it is will solve it.

crf450rr · Post by **crf450rr** » Mon Feb 11, 2008 4:48 pm

I'll turn the MDS off for a week and I won't tell my wife since she drives the car everyday.

I also noticed when you turn the MDS off it also turns the EGR off.
Will it hurt anything?

Post by **mikel** » Mon Feb 11, 2008 4:55 pm

crf450rr wrote:I'll turn the MDS off for a week and I won't tell my wife since she drives the car everyday.

I also noticed when you turn the MDS off it also turns the EGR off.
Will it hurt anything?

Nope, wont hurt anything.

Thanks