Army MSG's V

Hi, I'm new to this forum.

Has anyone had problems with zero gains or a loss of HP and torque after installing exhaust and air intake?

I have an '05 CTS-V (8,000 miles) with Magnaflow catback, LPE CAI and Superchips Micro Tuner. I even swapped the fluids for Royal Purple.

I ran a stock baseline last fall on a Dynoject 248c and saw a peak HP of 326 at 6,000rpm and peak torque of 324 at 4,200.

I ran two baselines on the same dyno yesterday with the above mods. One with the Superchips and one without.

I gained a whopping 2 RWHP at peak using the stock computer tune. Gained nothing in the mid range.

Installed Superchips and lost 3-5 HP and 4-6 Torque up to 4600rpm. I did see a peak gain of 4.8hp over the bone stock baseline. It also moved my torque peak up to 4,900rpm but the number is still 324. Eeek!

What gives? I wonder if its the car or the Magnaflow and LPE CAI that suck!

I've had some mod experience in the past. I built a 383 stroker LT1 in a Z28 and moded a LS1 in a C5. I've never seen such a poor repsonse to modification.

Florian

Its your tuner, Superchips just suck. FWIW. Get a tune on a dyno and you should see 15-20 rwhp increase.


F

98TADRIVER

iTrader: (36)

Definately the tuner. Magnaflow is one of the best out there!!!

zipdog

Don't expect much of anything with the exhaust, same for the intake. The canned tune is garbage, put some Kook's on the car and then dyno tune it.

blownCTSV

I had a superchips program and slowed down 2 tenths.That was about 7 years ago.
I hear things have not changed at Superchips.Dump the generic program for a tune tailored for your mods.

Army MSG's V

I have been planning on getting the Kooks headers as suggested. Just waiting on Kooks to finish the Magnaflow connection kit. I think they're almost there. The stock exhuast manifolds look really restrictive. More then GM admits. There is a considerable disparity between RWHP readings of stock CTS-Vs and stock C5 ZO6s.

I also agree with the need to get it dyno tuned. Anyone know of a reputable shop with CTS-V experience in the Phoenix area?

Thanks

obZidian

iTrader: (2)

more worries, have a dyno tune with your mods and you should be happy.... it wont be a whole lot but enough...

2c5s

iTrader: (11)

Give Chad at Extreme a call.

stkshkr

There's not a lot to be gained as others have said. You might want to try StealthV Engineering for a mail order tune of your PCM, I think you will be very happy with it. The dyno may give you a few extra HP at WOT, but the Stealth tune will give you great drivibilty

Retired Army CW4 by the way, you must be MI

Corsa exhaust. FG2's, Volant CAI. GSD3 275/40 rears. Car Motorsports front, rear, trunk mats, shoulder harness pads, and underhood insulator. Autovation pedals. Anodized oil catch can. B&M shifter. 06 differential. UUC bushings
Dyno = 340 rwhp 332 rwtq (Corsa & CAI only)
Coated SW long tube headers, RT Cats, KARS Stage III Kit, Maggie, Black FR cover, StealthV tune, 35% Tint, Raptor shift light, BFG Drag radials 245/40/18, Embriodered headrests
12.296@114.78
Dyno = 467.6 RWHP and 441.4 RWTQ

Army MSG's V

Yes, I'm in MI.

I just ordered a full B&B system with headers and catback from Gary at B&B. I must be getting lazy in my old age. I decided to have them do the install.

I see that B&B has changed their header/cat design. The cats are no longer welded to the collector. I know that B&B had problems with cats and gaskets blowing out. I hope the fix works.

I had B&B PRTs on my C5 and enjoyed the sound. The C5 with a Blackwing and B&Bs dyno'd about the same as the CTS-V with Magnaflow and LPE CAI. GM may have exagerated their power level on the 04-05 CTS-V. It should be 385 and not 400.

Say, anyone in Southern Arizona interested in a six month old Magnaflow system for $400?

verbs

I wholeheartedly disagree with that. Xtreme cannot tune LSx motors worth a lick.

The best tuner in AZ hands down is a guy named Nic Desjardins who posts on this board as Nic00Z28M6 I believe. His email is nd@asu.edu.

He does the tuning on all the big boys in AZ. I have his phone # if you PM me.

TNT V

Xtreme does a great job tuning these engines. They have done all of the work on my Corvette and can't be beat!

Travisimo

iTrader: (1)

The outside temperature could have played a part. Was the weather much different in the two times you dynoed?

Chiro v

iTrader: (1)

I have the Superchips in my car mainly because it can be put back to factory settings pretty easily. This is important because I'm going to be running nitrous and I've heard that aftermarket tunes which advance the timing is exactly the opposite of what you need with nitrous. I like the SOTP feel with the Superchips tune.

I'm taking my car to the track in the next few weeks and I'm going to make some runs with and without the tune to see if there's a difference in time. I think it'll be a cool experiment.

Army MSG's V

The temperature was 95 on the day of the stock base line and 75 degrees when I dyno'd with the Magnaflow and LPE CAI and noted the loss in HP and Torque below 4600 rpm. The BP was almost exactly the same. Both dyno tests were conducted at approx 1000 am. I should have had more power with the mods.

I was reading a GM High Tech Performance article on LS2 engines and noted their claim that the GM computer will pull timing when it senses an increase in intake airflow or a reduction in back pressure. I wonder if that's true for the computer in my car. It seems counter intuitive but maybe it's a technique to keep emissions in check.

I'm having the B&B headers and exhaust installed at B&B in Phoenix on 24 April. I'll stop by Xtreme and check on tuning options.

BTW: Royal Purple's marketing claims to reduce parasitic loss from friction seems like serious BS. I'm going back to Mobil 1.

Army MSG's V

I swapped out the LPE CAI for the Volant and headed to B&B in Phoenix where their R&D guru, Eric, installed B&B's new long tubes, front pipe with cats and x-pipe catback. The car was noticably quicker on the test drive and sounded awesome.

I then ran over to Xtreme Motorsports in Tempe and dyno it. I did notice that the car seemed to loose some power inroute. The dnyo test was an ugly baby. The A/F ratio seemed okay but the PCM is clearly pulling timing. Now the car is 5-20 RWHP down from the stock baseline.

I contacted Rick at StealthV and he has offered to send me a loaner PCM w/StealthV tune. That's amazing. Thanks Rick!


The B&B stuff looks awesome. The system is polished like crome from the header collector back to the tail pipes. The guys at B&B are a class act so I'm definitely not knocking them. I feel lucky that I was able to have them do the install; I've got no issues with rattles, rubbing or burned wires. Thanks Eric!

My V has some sort of problem. It may be the PCM programming. I've got my fingers crossed. We have a disintergrator at work that I could have thrown my pay check into.

2c5s

iTrader: (11)

Let's hear the horror story behind that statement.

TNT V

Well....I wasn't aware that Mike was no longer there so my experiences may no longer hold valid.

obZidian

iTrader: (2)

army msg's:

I read that the ls2 pcm does have that wonderful feature but unsure if the ls6, which is what we have, has this.

5-20rwhp, is that still with the superchips or by stock baseline you mean stock tune?

Ok, so you have increased the amount, theoretically, of air coming in and now, coming out of the motor. The stock corsa hasn't shown much in power production but now that you have a full exhuast, there should be an increase in power. THe only thing i can think of is your tune. OR maybe you have a bad maf sensor, knock sensor, something.... that is not allowing the added flow to make the power.

Actually, your choking the motor or its not syncronized. Not enough fuel perhaps or spark? What, if you know, was your exact A/F the last time you dyno'd and can you compare it to your intial STOCK baseline? How she idle? More lumpy than normal? Its definitely tune related but you never know, it could be something as a stupid sensor or plug wire that went loose. HAd that happen.... OR a bad spark plug... have you checked those? MAybe, just maybe that superchips tune got them coat'd and need to be cleaned or replaced... well, maybe.. Could be a bad ground or bad coil pack... a coil pack not connect correctly...had that happen also..

good luck brotha, let us know how it turns out....

obZidian

iTrader: (2)

Is this the extreme in tampa Fl.?