Whitty

Hey guys, just got back from the dyno tonight. figured may as well share some numbers with you all. I'm running a 2010 SS/TC with GMS1 and a K&N SRI. car feels great however looks like there is a flat spot on my graph across all pulls at about 4400RPM i noticed my pressure dropped from about 20 psi down to 15 for 1000 or so rpm then back up to 20 .... really stange... the turbo spools to 20 psi very fast just seems to be held back at this RPM range.. any ideas? I was dynoing in 3rd with All traction control settings off...

whitey_rolls

I'm complete noob on this forum but from all the reading I've been doing the past week I thought it was fairly common for the GMS1 tune to start crapping out once it got into the higher RPMS.

Obviously not a solution to your problem, but I think it is something pretty common.

DoMiStIc_RuSh_06

iTrader: (1)

I must say, Im not impressed with those number at all....considering cobalt daddy dynoed higher than that trq wise and only a couple horsepower under you and he's bone stock.

Whitty

sounds about right lol its kinda lean in the mid range as well according the RPD like 14.1 - 14.5 or so... cant wait to get a 2nd PCM n tune it

agreed... and my stock numbers were higher than his (same dyno for both of us both runs...) somethings not right agreed. just not sure what prob GM tune mixed with intake being untuned for.

DoMiStIc_RuSh_06

iTrader: (1)

As for the dropping down to 15 psi....that's the same thing that happened to me before all this **** took place with my car....I hope it's nothing serious man. My car now hold 19-22 psi depending on the day. I just got back from a drive and spiked 22 and held 20.

Whitty

yeah i spike 22 and hold 20 normally. however this is the first time i have been able to go WOT since GMS1 and watch the RPD the whole time to get an idea what my boost and afr was doing etc. i really hope i dont have to go down ur path!

Note as well that in my stock graphs are much MUCH smoother...

DoMiStIc_RuSh_06

iTrader: (1)

Yeah....it is odd....I don't think it's the intake. The beat way to see is to rotate th filter till it feels right. I think what's wrong my car Is that it's not spoiling up as fast as it was, that's why it doesn't pull as hard. But none the less....see if you can get someone to monitor the fuel trims each time you rotate the filter a bit.

Your stock graphs are uncorrected but the stage graph doesn't say....that could be why it's isn't smooth. Not sure just sayin

Cobalt_Daddy

Im telling ya take that damn intake off. It may sound better but im sure its throwing off your trims.. It may work well with a custom tune but gms1 is for stock airbox.. Hope you dont see jerrens issues :/

Bolted-N-LoweredSS

northvibe said he has stage 1 and k&n intake and his car runs like a top i dont think its the intake ..

DoMiStIc_RuSh_06

iTrader: (1)

You should dyno with your stock airbox on and see what happens.

rhynoj

wow man, you wasted no time getting this up haha, and thanks again for the ratchet.

DoMiStIc_RuSh_06

iTrader: (1)

Yeah I don't think it's the intake either....alot of people have it and no issues....sounds like it could be a map sensor going out or a boost leak. Maybe they didn't tighten
up your lower chargepipe up.

Cobalt_Daddy

Check my graph on my gallery it has a small flat spot around 4500 as well

Whitty

no problem at a ll

murrant22

iTrader: (1)

just tune on the stock one... get trifecta and get it hidden, you'll be fine. switchable is the way to go, i'd hate having to change pcms everytime i want to run my tune, when you can just switch on switch off!

Whitty

so it does... curves are very similar only difference is the intake... do u see ur boost drop tho at the same RPM or around there back to 15 - 17 psi ? (150ish kpa)?

murrant22

iTrader: (1)

and tune for the intake, no matter what i'm sure it'd throw the fuel trims way off if not tuned for.

Whitty

if i got tuned the only time the PCM would come out would be for dealer visits. so it wouldn't be that bad + read somewhere that even trifecta PCM's are getting picked up at dealers. I just dont wanna take the chance at all and the best way to be sure is make sure GM doesn't see a tuned computer at all.

murrant22

iTrader: (1)

i wouldn't be too worried about it, but the best way to make sure is not to get tuned at all if you're worried.

i also read somewhere that they can also see when you switch it all and all that junk, but thats all theories too i guess.

i'd be scared i'd have to go to the dealer, and i'd have the tune pcm in for so long and i forget about it lol

Whitty

K&N isn't supposed to alter fuel trims much more than the stock airbox... i say it isn't supposed to because now im uncertain.

good point, wont know til u go in i guess.

DoMiStIc_RuSh_06

iTrader: (1)

I dunno... After seeing all these dynos, I'm half tempted to cancel the intake I just ordered and part my car out, putting everything back to stock.

murrant22

iTrader: (1)

That is true, but still, every car varies, hell i have the same **** and Jerren and my car runs fine. His on the other hand...? Well we all know that story

80vetteL82

Basically the same as what I made with my Dejon SRI.....I made a LOT more tq though for some reason...like 20lb/ft more.... I was on a dynojet with SAE numbers as well

Whitty

if you are referring to the numbers in your sig? if so id be stoked with those on GMS1 ! are those from the Dejon? or other intake ?

edit: Just noticed u refered to ur torque numbers. yeah i wish i had 300 + torque. thats more or less my only issue with my numbers.

80vetteL82

Yeah, those numbers in my sig. They are with Dejon SRI only. Heres a link to my thread, the dyno graph is like halfway down:

https://www.cobaltss.net/forums/08-10-ss-turbocharged-general-discussion-152/dynoed-gms1-194171/