Stage1+ Vs. Stage2+ Losing PSI in Stage 2+

I noticed today my car was only holding 16-17PSI with a Stage 2+ MSCAI Map. So I did a test run from 2nd gear through 5th Gear to see what was going on. Sure enough, it was only holding 16-17 PSI and sometimes 18.
Well, I came home, loaded a Stage 1+ MSCAI Map and reset the ECU and had to drive to the city anyway so that put on 70 miles while the car was relearning everything. I came back to the same exact spot (Nice long straight away with nothing around) and floored it again from 2nd thru 5th again. This time I was holding 18-19 PSI. The car felt a touch more powerful in the Stage1+.
I data logged both maps and was just curious on if anyone could help me out here. I'm still learning and figuring out these numbers so any input would be much appreciated.

Also, I asked on the COBB section here if my car was setup for Stage2+ and I got a few responses that it was. So I tested it out. I'm thinking after this, I need to stick with Stage1+ if I want the most power (I switch maps like I do underwear based on how I feel that morning).

Thanks!

I'll say this with a grain of salt (can you do that?)

The Cobb OTS maps are tested and tuned to run with the exact setup quoted in the map. If you load the Stg1+MSCAI map with a downpipe, there are no guarantees what you'll get. One would assume you'd be fine... but the sensitivity of sensors and the precise calculations made by the ECU of a direct injection hi-strung hi-boost factory car don't leave a lot on the table. There's no sensor for "backpressure", but a MAP designed around the expected flow of the OEM downpipe will not be a good match across several parameters with an aftermarket DP. Your case is not unusual.

If you'll read all of the various AP threads here and at the other MS6 specific forums, you'll find that results for the Cobb OTS maps while using different parts are all over the map. Some guys run like crap when not on the specific map, others are fine. Others run better on the Stg2+MSCAI with the stock DP, a frontmount, and PG SRI... go figure?(just an example to illustrate the point). Bottom line, if your setup does not match the exact specs for that particular OTS map, you ain't guaranteed anything... that's where their Email Tune (forget actual name) or Protune comes in.

I'll be running an ETS TMIC and PG full length SRI withan SU Test pipe. I plan to try all the various OTS maps for +91 with some datalogging and see what the best one is to use as a base map and then perhaps do a little street tuning... or maybe sack up and go Protune... unless of course one of those maps turns out to be perfect.

Well, that explains a lot but also leaves questions for me. I understand each of our cars are different and some react different that others. To be honest, I like the Stage 1+ MSCAI 93+ because the car does hold higher boost and feels so much stronger. However, does that mean that it holding at 19 PSI bad for the turbo? I don't think so from what I read. Also, I only see it spike to 21.5 PSI. This is what the Stage 2+ is supposed to do.

I dunno, I guess I was just looking for a specific answer but now I know there isn't one. Thanks for helpin me out there and I think I have some more maps to switch out to see which one I like (car runs the smoothest) at.

As for anyone else, please, more info is good

Yup... in the end, unless you're running the exact combo specified by the map, there will be enough parameters (albeit minor)wrong that they become big enough to feel when spark actually meets fuel. Swapping maps out until you find one that's close is an option... don't forget to try the +91 maps too... sometimes that might be the magic number. And also don't forget that you can spend weeks messing around with OTS maps and never be happy... while a Protune is over in an hour or two and will be perfect.

Well I have the specified setup for the maps and I use 93 Octane and not 91. You think even tho I'm putting in 93 that it might run better if I use a 91 map? I'd have to try that out.

I like the idea of protune but I dont plan on stopping where I'm at. I still want to get a front mount or upgraded top mount, exhaust, fuel injectors and more. The problem is I can't get all them at once and will have to do a new tune every time. Plus the Cobb AP can now do all that stuff too. But I guess with those upgrades I kinda need a new tune every time anyway haha.

SamNavy said:

There's no sensor for "backpressure", but a MAP designed around the expected flow of the OEM downpipe will not be a good match across several parameters with an aftermarket DP.

Click to expand...

+1 I think a upgraded cbe may alleviate the drop in boost you are seeing. Is you waste get getting maxed out on the stage 2 setup? Compare your stage 1 map WOT logs to your stage 2 WOT logs. See if your WGD% on the stage 2 map is hitting 99%. If it isn't, you can try customizing your map and target boost by gear. Just my 2 cents.