Berfore and after tune , 93 octane .

Stock - 298 rwhp 322 rwtq
Tuned - 317 rwhp 336 rwtq

http://www.neweraperformanceparts.com/Images/g8gt%20dyno.JPG

I was working on different intakes til 1am last night , I tested 5 different designs and didn't see huge gains out of any of them , the one that flowed the most detuned the car so bad it was rediculous , it ended up pulling 4 degrees of timing and bounced around on 10:1 air fuel ratio the whole run with the stock tune . I think we will be coming out with 2 kits at this time , one that will be about a 6 rwhp gain with the stock tune and another 15 rwhp with tuning so you can use this one without a tune , and then the higher flowing kit that will require a tune that was basically no hp gain at all on the stock tune from how bad it detunes the car even though there is a lot of additional airflow . But , this all could change as we are still testing things , the kit that will not require a tune is being driven daily on our test car to make sure there are no major issues that come up , even so I would still reccomend getting your car custom tuned on a dyno if you are going to use an aftermarket intake on your g8gt .

Mike
www.neweraperformanceparts.com
sales@neweraperformanceparts.com
585-865-1832

Nice numbers! Was this a mustang dyno? Also, since you're using HP Tuners, does that mean you can't tune the TCM? Lastly, as far as intakes go, have you thought about testing one that goes in the front over the radiator, like the LS1 F-body's? I'm very interested in an intake that sits right in front of the throttle body, especially if it can utilize the hood scoops. If not, I guess a 4" tube to the side will have to do. The setup I'm looking to do is a good CAI, underdrive pulley, corsa catback, and a custom tune. Thanks for your help!

Dynojet dyno , note that peak horsepower was at 5200 rpms . Yes , you can tune the TCM with HPtuners , we don't do mail order tunes though , you will have to come to our shop to get a custom tune for your G8GT , unless you already have HPTuners then I can sell you a binary file that will get you close and you can fine tune it yourself . I don't think we are going to do an OTR intake , too costly for the same results .

So with a intake + tune = 330-335 rwhp or 34 hp more than stock ?

Very nice Mike!

So with a intake + tune = 330-335 rwhp or 34 hp more than stock ?

Yes , I'd say it will be between 30-40 rwhp with intake and tune , depending on the intake , and the tune . We were conservative with this tune with it completely stock , AFR as you can see is at about 12.5:1 and probably could have ran about another 1-2 degrees of timing in a couple places , but no need to get aggressive with it just yet . The exhaust is extremely restrictive on this car , so you really shouldn't be aggressive with your afr and timing with a cork in the back because it will increase combustion temp and also detonation . Some Long tube headers with high flow cats , and a descent axle back exhaust and you can definitely be more aggressive with the tune , I think the biggest power gain with the cars is going to be in the headers and exhaust (from a bolt on stand point) .

i believe your right, 30 hp sounds about right

Good numbers for sure especially through IRS and an A6 tranny. Sounds like the car will be a GREAT candidate for good bolt on power.

When I get some spare time (so many projects going on right now), I am going to test out the Yerra Rocker arms on it as well . And after talking with Nick at American Racing Headers today , there is a pretty good chance I will send the car down to him so they can make a set of long tube headers for it most likely in mid April , then those will be available immediately after that as well , from a bolt on part standpoint , I really feel that will be the biggest gain in performance for this car . The full exhaust is so plugged up , it is rediculous which is why I stayed so conservative with the tuning .

When I get some spare time (so many projects going on right now), I am going to test out the Yerra Rocker arms on it as well . And after talking with Nick at American Racing Headers today , there is a pretty good chance I will send the car down to him so they can make a set of long tube headers for it most likely in mid April , then those will be available immediately after that as well , from a bolt on part standpoint , I really feel that will be the biggest gain in performance for this car . The full exhaust is so plugged up , it is rediculous which is why I stayed so conservative with the tuning .

If you remember and it's not too much of a pain, please have your friend cut open the stock mufflers - I'd like to see what they look like.

I'll suggest it , but doubt this will actually happen . This is going to be a system designed up to the stock mufflers . I will talk to Nick (my friend) the owner of American Racing Headers , the manufacturer of the best long tube headers on the market today and see if he would be willing to do something along these lines , and maybe even replace the axle back with something as well so it is more than headers , cats , and mip pipes .

How much of a restriction is in the sound baffling? I though about replacing this part with a straight pipe and leaving the rest alone.

Quite a bit , plus it is just ugly !

THe stock resonator is huge and very restrictive..plus there is two glass pack type pre mufflers right under the rear seats..i only replaced the stock mufflers so far with flowmasters...because i was concerned about uncorking it too much without having a proper tune...like what happend to Mike...the intake air flow was very senstiive to changes and the computer tried to compensate..with the stock mufflers changed was the safest way until i see a more complete system..waiting on full system with headers, hi flow cats etc...and a intake that will make some decent rear wheel hp with the right tune tying it all in..im out in cali.soo cant drive down to NY or MI for the in person tune.

THe stock resonator is huge and very restrictive..

Do you have pictures to back that claim up?

No pics of resonator..that I took...the link above...i think the first pics you come to show a stock looking exhaust .where he says muffler .before the twin resonators ( hot dogs) ... i see the muffler as the resonator..and the hot dogs..or whatever as the pre muffler glass pack / additional resonators...u can see the stock mufflers too that look like the size of a huge toaster.. there really thick..and restrictive..video will be out of what my 2 chamber flowmasters sounds like tommorow afternooon ( ive still been recoverying from eye surgery ..cars been sitting shamefully undriven last couple of days )

u can see the stock mufflers too that look like the size of a huge toaster.. there really thick..and restrictive..

Again, please show pics.

sandawg are you some pic fiend? the pics are on the guys link above..
you can always do your own online research as well... if words are not descrptive enough for you...and you HAVE TO SEEE FOR YOURSELF! kinda guy....theres stock photo pics of everything...everywhere if you look hard enough...the pic u can see in my icon was the only time i was under the car last week before surgery and took it with the flows being put on..i didnt document the stock system with photos..as thats not what i was there for....i was there to be in and out as fast as possible with the super 40 flows

What could electric cutouts do? I want to keep the stock "too silent" exhaust system but was thinking I'd want to be obnoxious at times. If I put electric cutouts on, where would be the best place to put them, both for sound and to bypass restrictions? Would the car have problems with the stock exhaust if it were tuned based on the cut-outs? Would there be a difference in power between cutouts open and closed?

sandawg are you some pic fiend? the pics are on the guys link above..
you can always do your own online research as well... if words are not descrptive enough for you...and you HAVE TO SEEE FOR YOURSELF! kinda guy....theres stock photo pics of everything...everywhere if you look hard enough...the pic u can see in my icon was the only time i was under the car last week before surgery and took it with the flows being put on..i didnt document the stock system with photos..as thats not what i was there for....i was there to be in and out as fast as possible with the super 40 flows

If all the mufflers & resonators are straight-through then the system is not restrictive. I would like to validate if the G8's exhaust is or is not straight-through.

sandawg are you some pic fiend? the pics are on the guys link above..
you can always do your own online research as well... if words are not descrptive enough for you...and you HAVE TO SEEE FOR YOURSELF! kinda guy....theres stock photo pics of everything...everywhere if you look hard enough...the pic u can see in my icon was the only time i was under the car last week before surgery and took it with the flows being put on..i didnt document the stock system with photos..as thats not what i was there for....i was there to be in and out as fast as possible with the super 40 flows

Regardless of how the stock mufflers look, the inside of your new Super 40 Flowmaster certainly doesn't 'flow' very well. As you can see, there are considerable impediments:

Flowmaster Super 40

http://flowmastermufflers.com/images/_40_super.jpg

http://www.neweraperformanceparts.com/Images/g8gt%20dyno.JPG

www.neweraperformanceparts.com
sales@neweraperformanceparts.com
585-865-1832


Mike

It looks like the WB is reading close to the 11's up top , so is there a little more HP left on the table ?
You know the fuel cruve looks kinda like how some would tune the turbo 4 that the evo runs .

Sure , I thimk there is a bit more power on the table , but the car is stock ! The stock exhaust is rediculously restrictive , so I was playing it safe , let's do some long tube headers and high flow cats so the air coming out of the cylinder isn't being fought by back pressure reducing how much air comes out and I will lean it out a bit more and make some more power instead of risking detonation . I wasn't trying to be too aggressive with it just yet .

The stock exhaust is rediculously restrictive...

Until someone produces pictures of the inside of the G8's mufflers and resonators, this is conjecture.

I left the pos microwave sized mufflers lay where the fell when cut...dont need to show a pic to you..since I saw them in person...waste of a time to take a pic...if you want to go pick up the mufflers there in the dumpster in morgan hill....you can take all the pics that you want...its obvious you dont own a G8 why are you on here arguing technicals with the members?
Do you try to PROVE yourself..that you know better than someone else...cause..we dont have a pic..so we must be wrong? go look online..theres pics of anything u want online ...its a google away. Unless you actually are trying to prove a point that matters..which i havent seen one yet..stop asking members for pics..if they wanted to put pics up in the first place they wouldve.....

call the flowmaster hotline...and please...try to tell them because you see "impediements" that there mufflers must not flow well
Flowmaster operates the only exhaust Research & Design facilities of its kind in the world, centered around the SuperFlow SF-7100 engine dynamometer complete with E.C.A. (engine cycle analysis) equipment and also SuperFlow chassis dyno's. Through use of these dyno's, Flowmasters engineering staff can track the complete engine cycle in millionths of a second and can obtain exact technical data of each degree of cam rotation, from induction to the tip of the exhaust system, while also showing the power numbers that really matter, the power numbers "to the ground."
sandog its obvious....they dont what they are talkinga bout right......and of course.. YOU do..right?


Regardless of how the stock mufflers look, the inside of your new Super 40 Flowmaster certainly doesn't 'flow' very well. As you can see, there are considerable impediments:

Flowmaster Super 40

http://flowmastermufflers.com/images/_40_super.jpg

call the flowmaster hotline...and please...try to tell them because you see "impediements" that there mufflers must not flow well
Flowmaster operates the only exhaust Research & Design facilities of its kind in the world, centered around the SuperFlow SF-7100 engine dynamometer complete with E.C.A. (engine cycle analysis) equipment and also SuperFlow chassis dyno's. Through use of these dyno's, Flowmasters engineering staff can track the complete engine cycle in millionths of a second and can obtain exact technical data of each degree of cam rotation, from induction to the tip of the exhaust system, while also showing the power numbers that really matter, the power numbers "to the ground."
sandog its obvious....they dont what they are talkinga bout right......and of course.. YOU do..right?
just FYI, Flowmasters are probably the worst "performance" mufflers you can get. If all you were after was sound, you made a great choice tho ;)

full Pics from the G8 exhaust

http://g8gt.com/attachments/158d1171382462t-ex1.jpg
http://g8gt.com/attachments/159d1171382462t-ex2.jpg
http://g8gt.com/attachments/160d1171382462t-ex3.jpg
http://g8gt.com/attachments/161d1171382462t-ex4.jpg

stock rear muffler
http://g8gt.com/attachments/318d1175706782t-stockve.jpg

http://g8gt.com/attachments/341d1178078517t-muffler.jpg

stock rear muffler
http://g8gt.com/attachments/318d1175706782t-stockve.jpg

http://g8gt.com/attachments/341d1178078517t-muffler.jpg
Great work bluegoat06!!!

I can tell you what's in the big flat dual in/out in the middle. It is a dual tube straight thru oval glasspak. So my guess is the restricive part of the system are the monster cans at the back. Don't know about the cats, but they are BIG!

Everyting else looks fine for stock parts but the rear mufflers. i wonder who designed such flow path in the mufflers?

call the flowmaster hotline...and please...try to tell them because you see "impediements" that there mufflers must not flow well
Flowmaster operates the only exhaust Research & Design facilities of its kind in the world, centered around the SuperFlow SF-7100 engine dynamometer complete with E.C.A. (engine cycle analysis) equipment and also SuperFlow chassis dyno's. Through use of these dyno's, Flowmasters engineering staff can track the complete engine cycle in millionths of a second and can obtain exact technical data of each degree of cam rotation, from induction to the tip of the exhaust system, while also showing the power numbers that really matter, the power numbers "to the ground."
sandog its obvious....they dont what they are talkinga bout right......and of course.. YOU do..right?

just FYI, Flowmasters are probably the worst "performance" mufflers you can get. If all you were after was sound, you made a great choice tho ;)

TrickStang has it right. You don't need to be a genius or have a physics degree to see that Flowmaster mufflers do anything but flow...they may as well call them Blockmaster Mufflers since that is what they really do to air flow:

http://performanceparts.com/performance_parts_images/flowmaster_42443.jpg

http://www.americasradiator.com/mufflers/Flowmaste2.jpg

http://shop.enthusiastworld.com/images/m/1026/24052.jpg

http://www.truckcustomizers.com/images/prods/FLW/R4FLW799.1B.jpg

http://www.flowmastermufflers.com/products/images/cutaway_10_series.jpg


Compare these to any Magnaflow muffler:

http://www.svt4u2try.com/Mystuff/Mustang_FAQ/exhaust_files/image008.jpg

http://images.magnaflow.com/05news/magazine/gifs/sportc01.jpg

I'm glad you like your Flowmaster, but just be clear that you are not getting even close to optimal performance with it. For that, you need to get a straight-through muffler like a Magnaflow, Dynomax, or Bullet.

full Pics from the G8 exhaust

http://g8gt.com/attachments/158d1171382462t-ex1.jpg
http://g8gt.com/attachments/159d1171382462t-ex2.jpg
http://g8gt.com/attachments/160d1171382462t-ex3.jpg
http://g8gt.com/attachments/161d1171382462t-ex4.jpg
The piping looks very good, especially for stock. what diameter is it?

so Im thinking get rid of that big ass resonator/ muffler after the cats and replace with a X or H pipe, leave the glass packs, then replace the rear mufflers with some good maggnas!!!!!
Would that work???? Probably help it a bunch!

Maybe just swap the rear mufflers and leave the rest how it is...?

I must have missed the rear mufflers when I stuck my head under the G8 I looked at, because it looked like a center muffler to me with virtually straight pipes back. I'll definitely have to take a second look... I was shocked to see those huge fat boxes in the back on those photos!


The connections after the header, and the header itself looks like the worst part of the puzzle. I imagine an engine like the G8 should need at least a 3-3.5" exaust through the whole system. My 1.6 Mini runs on a 2.5 system, and the best systems run at 3" (although it is supercharged.) Anyone know what manufacturers might be working on G8 systems? What kind of exhaust does the Corvette/GTO's work best with?

Actually , Flowmaster makes the cheapest muffler out of the cheapest materials and stamps a Flowmaster price tag on it .

The worst place appears to be the pipes between the resonator and the hot dogs. Looks almost like the infamous U-bend on the Grand Prixs. As for diameter, it may not a larger diameter overall. The bends seem to be pretty good for a factory exhaust.

Chip

FLowmasters...everyone has an opinion.i know i know...
the pics you all showed with the stock system and the other mufflers pics are great ...thanks to all ....
if any one knows about that big pre-muffler ..and the 2 glass packs at the very beginning ...let me know what has worked for you..i was alil gun shy on going with an x pipe or straight pipes..ANYHOW
FLowmasters..everyone shames them lol but they actually are not restrictive...they are the only muffler withought the baffles/glass pack... they have chambers..the exhaust easily flows right out of them....just grab one .put it in your hand and check it out end to end.. im not saying there the BEst .but ..i have used them since ive been 16 on my first car...(18 years now ..)..ive had them all ...magnaflow.(good but didnt like the sound) ...the cherry bomb cheapies, dynomax..( worse sound than magnaflow IMHO) ...now ive heard really good things about corsa..or however u spell it..from the vette crowd...but there like the cadillac of mufflers as far as price..IF they develope and dyno a fulll cat back system that produces Street HP ..i will def swtich over.. but ya... FLowmaster still holds more records in races ...worldwide than anyone i am aware of..so i duno..just my 2 cents..i am in no way an expert..and not trying to argue with anyone.....its just what I have looked at myself..the chambers...are just that...and flow better than (it looks) .It would be interesting if any muffler guys on here could do a air flow chart...i duno...they probally arent the best....ever made..but they do flow lol

My muffler guy (30 year vetran- has done thousands of stock and highly modded cars) whos job is to make money ..mind you...on customers...said the stock pipes are "killer" AND leave em for now. He said soo many times..have people tried to in his opinion go against his judgement and put on 3 to 3and half inch piping....and lose soo much backpressure..the car runs worse...so he advised me to stay safe..keep the pipes...replace the back mufflers only...and wait until someone else takes off the main premuffler / resonator whatever it is...and the 2 glass packs...and see what there results are...
he did have a guy with an Hemi charger go against his advice and go like 3 inch all straight back...the day or two before i did mine.and he said it barely ran..just something to think about...cause the G8s computer is really really senstive IMHO

The G8's computer is sensitive , this is true . Just because the bends in the exhaust are good , doesn't mean it is a good exhaust system from cylinder head to exhaust tip . This info will be coming in the somewhat near future so we will see what happens !

Wow awesome exhaust pics. Those muff are f'n huge!