Kenne Bell cold running problems help

[mustangtcs]

I have had these issues ever since I put the kenne bell on my car. Here is my setup. 2005 Mustang GT auto 32,000 miles. 4.10 gears. Kenne bell 2.6 stage 1. SCT BA2600 maf. Siemens deka 60lb injectors. brisk 3vr16s plugs. Kenne bell BAP wired on at all times. 3 3/4" pulley. Tuned by Jon Lund in person at evolution performance. My problem has been there ever since I installed the supercharger and using Jon's startup tune and is still there today after final dyno tune. When I first start the car it idles great at 14.5 afr. When I tap the pedal nothing happens. I could put it to the floor real quick and get no response. When I try to drive its difficult because I have to hold the pedal down for a bit before it moves. The Air/fuel will even dip lean for a split second during this hesitation period. Now if I try to get on it at all and I have to in order to get the response its sputters above 3000 rpms but the afr is at 10.1 or so. But once the car is warm it drives great and pulls to redline hard. also around 11.4 afr. The hesitation is less but still there. Also my mpg's are around 8 miles per gallon. This has been since the beginning of last winter. While at the dyno the car was hot because I had drive it an hr there for the tune so Jon didn't get to experience this. I have datalogged a lot and lund racing says the logs look good. I originally had autolite ht0's and just switched the plugs to brisk today and no change. I am close to just taking my car to Evolution and dropping it off and just letting them figure it out but if anyone could help it would be great.

UPDATES WILL FOLLOW WHENEVER POSSIBLE

 

[BruceH]

I realize that your tuner has a fantastic reputation and that I'm just a self tuner hobbiest who has only worked with my own setups.

With that said I've experienced what you are experiencing and was able to correct it in the tune. IMO the sct values for cold motor forced induction are wrong and not adjusting them will result in what you are experiencing. It takes some time to get it right for the application. Maybe you could hire a tuner like lito who has the time and patience to get driveability to your liking. Every setup is different and it can take awhile to get it right. I think most tuners advise to just warm the car up before driving it. It doesn't have to be that way.

 

[mustangtcs]

I just datalogged my car doing this and I watched the air/fuel goes to 10.1 so I corrected my original post. You could be right but Lund has been willing to help so I am going to send them this log and tell them I am still having the same problems. When Jon did the dyno he said that he changed the cold startup file to the same files as the roush cars. I worry that maybe one of my wire connections I had to do to install the kenne bell might be bad but then again I doubt the connection would fix itself everytime the car is warm. Also the MAF was used when I purchased it. And I even considered bad intake manifold gaskets. No check engine lights though. I checked vacuum cold and its 20 inches at idle cold.

 

[eighty6gt]

-20 psi?

Cold tuning is obviously a bit challenging.

 

[mustangtcs]

in.-Hg on a handheld vacuum gauge. Not psi on a boost gauge.

 

[GoneFord]

I have had these issues ever since I put the kenne bell on my car. Here is my setup. 2005 Mustang GT auto 32,000 miles. 4.10 gears. Kenne bell 2.6 stage 1. SCT BA2600 maf. Siemens deka 60lb injectors. brisk 3vr16s plugs. Kenne bell BAP wired on at all times. 3 3/4" pulley. Tuned by Jon Lund in person at evolution performance. My problem has been there ever since I installed the supercharger and using Jon's startup tune and is still there today after final dyno tune. When I first start the car it idles great at 14.5 afr. When I tap the pedal nothing happens. I could put it to the floor real quick and get no response. When I try to drive its difficult because I have to hold the pedal down for a bit before it moves. The Air/fuel will even dip lean for a split second during this hesitation period. Now if I try to get on it at all and I have to in order to get the response its sputters above 3000 rpms but the afr is at 10.1 or so. But once the car is warm it drives great and pulls to redline hard. also around 11.4 afr. The hesitation is less but still there. Also my mpg's are around 8 miles per gallon. This has been since the beginning of last winter. While at the dyno the car was hot because I had drive it an hr there for the tune so Jon didn't get to experience this. I have datalogged a lot and lund racing says the logs look good. I originally had autolite ht0's and just switched the plugs to brisk today and no change. I am close to just taking my car to Evolution and dropping it off and just letting them figure it out but if anyone could help it would be great.

Though nothing as severe as you report, I do have a serious stumbling issue if I tip in the throttle before my 20 second timer countdown ends on a cold start. But after that it's all fun.

My tuner did build my tune from the ground up. I'm sure your tuner will get this fixed soon. How long have you had the KB?

 

[Brezick]

Jon tunes very safe and I can not blame him. My Lund tune performs well at the track, where I want it to, but its a bitch to get it up and going. I get the same hesitation/lag on the throttle as you mentioned. I just let it sit in the driveway for 10 minutes before going anywhere.

I actually had another local tuner try his tune and the drive-ability is 10x better, but it does a bit worse at the track. So I use one tune to ride around town and switch to Lund at the track.

 

[eighty6gt]

in.-Hg on a handheld vacuum gauge. Not psi on a boost gauge.

Yeah that's good, I just checked and my digital gauge reads in inches of vac and I get the same reading.

 

[mustangtcs]

Alright I feel a little better knowing I am not alone so maybe it is just the tune. I sent them a message on the lund site. I will keep you all informed if I fix my problem whether it is something I did or something in the tune.

 

[TexasBlownV8]

Keep in mind, your afr on a wideband will have a slight delay. And, it should normally vary around 14.7 at idle and when driving, not staying steady.

 

[mustangtcs]

Thank you texas blown. It is around 14.7 at idle and when steady cruising on a cold motor and at operating temp.

 

[Racer47]

Remember that 14.7 is only for 100% gas. Many of us have 10% ethanol fuel which is 14.1 stoich.

 

[eighty6gt]

I idle at 14.8 to 15.2. Wish I knew if this were normal (tune has idle lean to save fuel,) or if it's my wideband, or something else. My car has done this with all of its tunes, and 2 different widebands.

 

[BruceH]

Remember that 14.7 is only for 100% gas. Many of us have 10% ethanol fuel which is 14.1 stoich.

An American wideband will represent lambda as 14.7. For example I have 14.1 for stoich in my tune but my wideband still reads 14.7. Same thing happens when I run E85. Stoich is set to 9.8 but the wideband reads 14.7 or so.

 

[eighty6gt]

That's kind of annoying.

 

[BruceH]

That's kind of annoying.

I'd much rather read in lambda. Actually we do but it's represented as 14.7, lol. Everything in the tune except for the stoich is in lambda.

 

[mustangtcs]

UPDATE. Ok so I talked to Jon and he said how he still doubted that there was any tune issue but did revise it by raising the throttle sensitivity up 15%. But I also did something new. Before loading the new tune into my tuner I tried to update my firmware because it wasn't current. Well I couldn't. I remembered that in November when I started the supercharger install that I went to update the tuner and I couldn't and I never did. This time I called SCT and had them remotely go on my computer and update my tuner. So now my tuner has the newest firmware and the new tune. I put the tune in the car and just driving around during errands my gas mileage immediately improved from the 8mpg before to 16mpg now. Car drives like stock when not in boost and gets the mileage I was getting stock! The cold start thing hasn't been noticeable but after I really get to drive the car a few times I will let you all know. I haven't talked to Jon yet because I want to be sure the cold running issues are gone first but so far its great. Do you guys think updating my firmware fixed my problem?

 

[Timmbo]

Your really going to hate that Kenne Bell. They are one of the worst performing superchargers on the market. Should have bought a Whipple!

 

[mustangtcs]

Timmbo your right man. I hate it! Instant boost and torque makes me feel like I'm driving a big block. But getting small block gas mileage? I have actually followed your car a bit. I saw it on youtube. I think somehow I found it when researching my tires. M&H Racemasters. Now that the weather is warming up they will go on the car soon. I'm hoping for an 11 second 1/4 mile time. My car is auto with 4.10 and soon for the 275/50/17 drag radials.

 

[crownaviation]

I realize that your tuner has a fantastic reputation and that I'm just a self tuner hobbiest who has only worked with my own setups.

With that said I've experienced what you are experiencing and was able to correct it in the tune. IMO the sct values for cold motor forced induction are wrong and not adjusting them will result in what you are experiencing. It takes some time to get it right for the application. Maybe you could hire a tuner like lito who has the time and patience to get driveability to your liking. Every setup is different and it can take awhile to get it right. I think most tuners advise to just warm the car up before driving it. It doesn't have to be that way.

This is the truth!!

Jon tunes very safe and I can not blame him. My Lund tune performs well at the track, where I want it to, but its a bitch to get it up and going. I get the same hesitation/lag on the throttle as you mentioned. I just let it sit in the driveway for 10 minutes before going anywhere.

I actually had another local tuner try his tune and the drive-ability is 10x better, but it does a bit worse at the track. So I use one tune to ride around town and switch to Lund at the track.

I had a reputable tuner (names not necessary) tell me that is just how these cars are on cold start... If someone tells you that then walk away (unless you are driving a Pro-Mod lol). Lito resolved all my drivability issues in like two revisions.. I never used another tuner since. Use what WORKS for you!

UPDATE. Ok so I talked to Jon and he said how he still doubted that there was any tune issue but did revise it by raising the throttle sensitivity up 15%. But I also did something new. Before loading the new tune into my tuner I tried to update my firmware because it wasn't current. Well I couldn't. I remembered that in November when I started the supercharger install that I went to update the tuner and I couldn't and I never did. This time I called SCT and had them remotely go on my computer and update my tuner. So now my tuner has the newest firmware and the new tune. I put the tune in the car and just driving around during errands my gas mileage immediately improved from the 8mpg before to 16mpg now. Car drives like stock when not in boost and gets the mileage I was getting stock! The cold start thing hasn't been noticeable but after I really get to drive the car a few times I will let you all know. I haven't talked to Jon yet because I want to be sure the cold running issues are gone first but so far its great. Do you guys think updating my firmware fixed my problem?

nope