I'm looking for some answers for those who actually have a GMS1 Tune with bolt ons (down pipe, CAI, SRI, Charge Piping etc.).

Reading about the GMS1 tune it sounds as though the learn down feature while not eliminated has been increased to accomdate more power. Because of this with your bolt ons do you still have issues with Fuel Trim? Or does the computer recalibrate for the bolt ons to keep a proper air/fuel ratio.

If some people who actually have the GMS1 fill me in on this it would be appreciated. Now I am sure some people will be eager to right how I'm better off going with Trifecta because it's better. Those aren't the comments I'm looking for.

Also for those with the Tune, have you noticed a significant change, and would you spend money on it again?

 

You'll see whta I got in my sig.

So far I feel the GMS1 was worth it. There is a big difference in the 3500-5500 RPM range, but the overall is well worth it.

I just installed my Catless DP this week, drove for over 500 km with it so far and no cel. The souns is nice, not too loud but u hear it when I go woot, and apparently the boost lag is shorter, but that must be very minimal as I didn't see any difference whatsoever. I did notice a small performanc increase though. Nothing major but a little extra punch over the stock DP.

As for the fuel trims, I don't know crap about this so I can't help you. But since i have no CEL assume this is good? lol

 

The K&N SRI and new style AEM cold air intake seem to be fine on the fuel trim department without retuning. Don't buy a used AEM though unless you know it has the new insert, the old style skewed the fuel trims quite a bit.

 

Loving my K&N SRI

Custom tune > Stage 1

 

I got my GMS1 installed together with my cat back; other than that the car was still completely stock. There was a big difference in pull and a deeper exhaust note.
Next I got my DP installed. Huge difference in power and sound! You can hear the turbo spool and the exhaust produces a deep rumble. Most recently I got my AEM intake. Wow. Again a very significant increase in power, very noticeable spool sounds from the turbo, and lovin' the blow off valve sounds on upshifts. I have had no issues or CEL's. I may or may not get a Trifecta tune in the future, just because it's never enough (lol) but so far I'm extremely happy with my mods and the GMS1. Definitely worth the money IMO, and it has turned my stock SS/TC into a little monster....!
__________________________________________________
Black 2010 SS/TC – G85 |Debadged | GMS1 | Hahn 3” DP and Catback | AEM intake | GM racing pedals | OZ Ultraleggera rims |DEPO 4th gen projectors w/ 6K HIDs | smoked LED tails | 20% 3M tint |Pioneer Avic Z110bt head unit, Alpine PDX-5 amp, Focal speakers all around

http://www.cardomain.com/ride/3835837

 

you just answered the question I had "colodude18". I have a 08 with the k n n drop in and the GMS1, I just purchased the MPX cat down pipe and catback exhaust. I was going to ask if there is power gains, WITHOUT TUNE, I wanna keep my warranty. Im debating about getting charge piping...but am not really sure what they do, or if theyre worth it. thanks

 

GMS1 w/ bolt-ons will put a grin on your face.
Custom Tune w/ bolt-ons will make you **** your pants.

get a custom tune...

 

I have stage 1 gm kit, hahn high flow catted dp, injen charge piping, k&n sri and I would buy it again.

I like its increased power but its still manageable. I'm more into suspension/handling and light weight though. I never wanted insane power as its kind of useless if you just spin all the time and on a road course you dont have to have it. I did buy a second pcm that I plan on tuning with hptuners. When I tune I only really would want 350whp or so as I'm not into drag racing. Also once you go aftermarket tune, it just more work, logging, making sure the trims are ok, afr's etc. more stress on parts and wears tires

Ya I would buy the stage 1 again and the same bolt ons.

 

Concerning the OP's question about bolt ons with the GMS1 and the learn down feature, does anyone have actual dyno sheets showing improvement when the bolt ons were added? I know I'm skeptical and I'm not saying anyone is lying but, "it sounds faster" or "it feels faster" doesn't quite answer the question for me.

I would love to see some real results with before and after dynos showing exactly what gains were or were not achieved, along with how much they cost? To me that would also answer the OP's question of whether the mods were worth it, or not.

Dog

 

Of course the Dyno Sheets are always welcome. I'm glad to hear people are able to not have issues with Bolts on with the GMS1 though. I also understand the Trifecta tune is better if you are having the bolt ons, but I want to keep my warranty.

 

Bah i have gms1 without any bolt ons and im happy with it!! Warranty and extra power ftw!!! I would definately buy it again!!

 

We need a dyno of GMS1 and bolt ons..........someone save the day!

 

For most people it's an issue of warranty.

 

you wont find much of anything. Its expensive to dyno and before/after are far and few between. Hopefully someone does but no one really does. So if you can, go for it. I don't trust dyno's.....

 

I'm in the middle east or I would haha.

 

oh. Ya I just don't trust anyone with my car, dealer, dyno, no one...I swear it would come flying off the dyno.

 

lmao...... BRO THERE WILL BE NO ONE WITH GMST1 AND BOLT ONS TO DYNO MORE THEN 300WHP, AND IF THEY DO THERE IS A ISSUE WITH THE DYNO.. Boosting to 20-23 lbs and stock timing and there tq managment and ect there should never be a 300 gmst1..... theres more to the tuning then just tho few things, its just simpler to say a few lol.... And if there is a gmst1 car at 300whp its prob becase its -20 * outside lol..

your best bet is to run gmst1 sensors and customer tune. (its what i have) and its what i recommend for people who are boosting more then 24. and i wouldnt recommend this unles you plan on meth "which youd need a customer tune to use to get the full potential"

 

I can dream haha.

 

Lol one day gmst1 and other tunes will be created equal..... Lmao

 

Ok. So I have not been on this forum in along time. But I have the GMST1 tune with all HAHN bolt-ons. 11-13-2010 I had my car on the dyno which was a dynojet. I had 91 oct pump gas and put down 303whp with 321 torque. I have been to the track and my best time in the 1/4 on street tires was 13.79 @ 105 mph. Honestly I am happy with my car the way it is for now and I'm still under warranty. I have never had any issues with CEL's either.

 

would you be willing to post the dyno sheet im interest in the torque on your set up

 

Me also, as the average I've seen with full bolt ons and GMS1 has been between 280-290 whp.

I got 276 whp with GMS1, I had full bolt ons minus a intake.

 

Here is my dyno from when I was GMS1 and 2.5" catback (which is basically stock) and maybe a CAI, but I don't remember anymore. I don't have a baseline for comparison unfortunately. This was on 91oct.



Every dyno is different of course. IIRC I ran a 13.6 1/4 at around 105ish with this setup. Also, after adding some more bolt ons I raced a tune only 'balt SS and we were neck and neck. So GMS1 + full bolt ons ~= Custom tune if you are only talking about power.

Edit: Regarding a custom tune + GMS1 for the sensors. DO NOT GO OVER 25PSI WITH THE STOCK TURBO!!!! It will push the turbo way out of efficiency range, push temps way too high and blow your engine. Multiple members have done it on here, especially any who went near the 30psi mark. The GMS1 is great for keeping your warranty, but once you go custom tune don't make the mistake of pushing things too hard.

 

Ok so here is my dyno sheet. GMST1 with all HAHN Bolt-ons. HAHN CAI, HAHN IC, HAHN Charge piping, HAHN 3" Downpipe with cat delete, HAHN 3" Catback Exhaust. This run was on a dynojet with 91 Oct.

 

Did you dyno at AZ dyno chip?