Boost cut, why bother?

[Micaspd6]

I have been reading and experimenting with my MS6 for 4 months now and have not even scratched the surface of mods that could be done.

I did the one muffler delete and the Cobb SRI with the Forge BOV. Now I get so much boost cut I don't know what would make me take this any farther. The car is slower 0-60 each time I get the cut then when it was totally stock! Granted if I can avoid the boost cut the car feels quite a bit faster/stronger. The problem is the power is not repeatable and when you need it it's not there.

It seems that even if I go all the way and do a ECU and full exhaust I will still see this problem. I want reliable power when I need it. If you are in a autocross or on a road course and you need the power because you are on the edge you cannot afford to be bogging down with boost cut. What can I do and in what sequence without wasting my money?

I have been tweaking the suspension because that is what I like to do to make the whole car faster everywhere. I want the power also but what the hell has to be done to get "good" power and usable non peaky power?

Thanks for listening and I look forward to your responses.

 

[bova80]

man i have never got boost cut and i have more mods than that.

 

[JSpeed 6 JLA]

...more then likely with the mods you listed you are fuel cutting from a boost leak somewhere, atleast thats what it sounds like.....

 

[AWDTerror]

replace your intake with the stock on and see what happens, could be something with the maf housing

 

[Micaspd6]

Well I thought the cold weather was the problem but it is continuing to do it even in the 60's. The only time it will really happen allot is if the gas pedal id pushed to quickly. If I just tip into it till the boost is up then it will most likely be fine. But when I am shifting quickly and the gas is pushed faster that is when the sputtering and bogging will happen. This is when the boost goes over 16 psi. No matter what I do with the BOV I can get spikes to 17-19psi, this is the real problem right? If I had a boost leak would the spikes be that high?

 

[djmarkian]

Ah I feel your pain, one day the car runs good and the next boost cutting, I live in NYC and the weather has been cold and trust me it did it to many so many times, but sometimes it doesnt. Dont get me wrong our car is unique and I love it for that but sometimes she can be very moody lol...

 

[FORZDA 1]

I have been reading and experimenting with my MS6 for 4 months now and have not even scratched the surface of mods that could be done.

I did the one muffler delete and the Cobb SRI with the Forge BOV. Now I get so much boost cut I don't know what would make me take this any farther. The car is slower 0-60 each time I get the cut then when it was totally stock! Granted if I can avoid the boost cut the car feels quite a bit faster/stronger. The problem is the power is not repeatable and when you need it it's not there.

It seems that even if I go all the way and do a ECU and full exhaust I will still see this problem. I want reliable power when I need it. If you are in a autocross or on a road course and you need the power because you are on the edge you cannot afford to be bogging down with boost cut. What can I do and in what sequence without wasting my money?

I have been tweaking the suspension because that is what I like to do to make the whole car faster everywhere. I want the power also but what the hell has to be done to get "good" power and usable non peaky power?

Thanks for listening and I look forward to your responses.

Your sig says you have a DashHawk. I recommend you use it to the fullest and datalog the LOAD, IAT, BAT, AFR, etc. and you will help find the answer. I run 18psi boost on the OEM turbo with an XEDE EMS set to the MS3 base maps for now and I've never had "cuts" other than the rev limiter shutting down the fun at max revs. I've read many posts about fuel/boost cut, but have yet to see any specific data supporting it. Data is the key. Personally, I think it is the "LOAD" value that is the trigger. I also theorize the ECU calculates the LOAD from the MAF/MAP/IAT/BAT/ECT. Data analysis will tell the tale if there's enough data gathered. More is better.

 

[Micaspd6]

I will check out the DH info more closely and see where I need to go with this. I do notice the condition is not bad when I "tip in" the throttle rather than hitting it all the sudden. This could bolster your load theory.

 

[speed6freak]

Anyone know any quick easy mods to give a little more boost?

 

[mrlilguy157]

I just read over this, it looks as if you're getting fuel cut. If you can feather into boost, then you're able to work around the fuel cut area (bottom end of the power band) because the car isn't demanding the excessive fuel to meet the demands of the boost.

With an upgraded fuel pump you will see a much broader curve because there is more fuel available at the proper pressures in the bottom end. I hope this helps. Feel free to PM me if you've got more questions.

You're welcome to trade those wheels for a pump upgrade

 

[FORZDA 1]

I just read over this, it looks as if you're getting fuel cut. If you can feather into boost, then you're able to work around the fuel cut area (bottom end of the power band) because the car isn't demanding the excessive fuel to meet the demands of the boost.

With an upgraded fuel pump you will see a much broader curve because there is more fuel available at the proper pressures in the bottom end. I hope this helps. Feel free to PM me if you've got more questions.

You're welcome to trade those wheels for a pump upgrade

Still sounds like the LOAD value is the trigger. I would guess, without any data to review, that you could change just about any parameter (IAT, MAP, MAF, BAT, etc.) and it will change the onset rpm and/or eliminate the problem.

 

[AUTOwrXER]

My understanding is that the OEM fuel pump is a two-stage design with high and low voltage triggers. When you replace it does it cause other issues in the engine mapping? Also, is the common fuel pump upgrade the Walbro 255 that most every other car uses?