[Stubbsy]

Hi there I'm new to this forum and are looking for some advice, I own a supercharged 3.7ltr
I5 in a 2007 H3 Hummer. The kit I am using is designed for a 2008 model and fits the 2007 no problem until it is time for tuning, the 2007 has a PCM for both engine and transmission, the 2008 has an ECU for the engine only and a PCM for the trans etc. My tuner has started from scratch with the stock PCM and has done a great job except for a few niggling little problems that he believes is from the limited adjustable perameters using EFI Live.
Has any one on this forum piggy backed a Motec or similar to there I5 for tuning a forced induction engine ? and if so what did you use and was there any problems with the trans function after fitting. Here in Australia there seems to be no one who has fitted an aftermarket ECU to an I5.
I have attached some photos of my set up.

CHEERS STUBBSY from down under

 

[AceX]

I don't know of anyone who is running a new engine management system.

Here in the states, we prefer HPTuners for these ECM's. Getting an HPT setup would be MUCH cheaper. Also, hit up 04colyZQ8 for some first hand advice. He's used both programs from what I understand.

 

[limequat]

For low to mid boost the P12 is more than capable.
It looks like your MAF may be the stock diameter, and that would be one problem. Increase that to 3" or 4" and you'll be able to read all the boost you need.

I've been involved with several boosted P12 projects. Admittedly, dialing in the maf can be a pain, but certainly not insurmountable and definitely cheaper/easier than a full on custom control system.

Good luck!

 

[05_quick4door]

What issues specifically is he having?

The p12 isn't as bad as some make it to be. I'm quite fond of its simplicity. Keep in mind you could also make a 2 bar setup with the p12 you just loose some resolution (not really a big deal)

As for aftermarket - I like megasquirt. It's cheap and has a big open source following. The i5 uses a 58x crank wheel that is already supported in the wheel decoder selection.

 

[Stubbsy]

What issues specifically is he having?

The p12 isn't as bad as some make it to be. I'm quite fond of its simplicity. Keep in mind you could also make a 2 bar setup with the p12 you just loose some resolution (not really a big deal)

As for aftermarket - I like megasquirt. It's cheap and has a big open source following. The i5 uses a 58x crank wheel that is already supported in the wheel decoder selection.

The current issues are an annoying hesitation when you lift off the throttle between 60 - 130kph when we have driven on the road with the lap top capturing live data it appears to retard the timing 28-30deg. We have an intermittent dead spot on accell after you have rolled off the throttle down a long hill, i'm no expert on tuning EFI and my tuner does have loads of tuning experience but mostly on V8's. We cant replicate any of the problems on the Dyno you have to drive it on the road to feel what it is doing.

Cheers Stubbsy

 

[05_quick4door]

You mentioned efi live earlier , while I don't use it, I have the software.

I would be interested in looking at a log and tune file if that's OK.

[email protected]

 

[FixxxerKH202]

Do you have a bypass valve installed? Sounds like surge to me since you are only having problems when you let off.

 

[1BADI5]

@Supermodulation

I know James is familiar with the unique issue between the 07/08 model years; hopefully he'll jump in with some information

 

[Stubbsy]

@Supermodulation

I know James is familiar with the unique issue between the 07/08 model years; hopefully he'll jump in with some information

Thank you all for chiming in, I will speak with my tuner next week and show him your posts
Hopefully we can get something sorted without having to use a full ECU swap.

 

[FixxxerKH202]

Let us know. Cory will be more help because I don't have efi live and I'm not familiar with it so I won't be able to view your tune file.

Some new question as well just so we have all the info here.

What have you done for fueling? Larger injectors, BAP, etc...

How much boost are you running?

Did the kit include a bypass valve to equalize pressure on both sides of the blower after making boost and closing the throttle?

Lastly if you can post of the tune for one of the guys here with efi to get us some info out of or just have your tuner give us an idea of what the motor is doing when these issues occur(sensor readings)

I think HpTuners is a little more forgiving when tuning these motors for boost, it might be worth asking your tuner if has a friend or something with it. I could be a lot more help then because I have a 2007 with a powerdyne centrifugal blower and got it going fine.