I would like to see what tony mamo thinks about this. 14rwhp over ti's. He did a test with cutouts and only gained 5rwhp on a car that made 530rwhp. Considering i am on the stock ti's and make over 500rwhp i would like to see a dyno from someone other than lg. Or i would gladly volunteer to drive up there and be their test mule.

 

Finally a comment that relates to this thread. Too bad we had to wait for the OP to post it. LOL. Hey c5_ls1_6spd, stay tuned to new threads. We will have some results. Gotta love a sponsor thats willing to give, to get. Not saying anymore then that.

 

allngn, no offense but your car is setup to dyno high. i think that is one of the reasons you have trouble at the track. your motor is set up well, but your drivetrain is setup to be a dyno queen. my car puts down around 390 rwhp corrected and bust out mid 11s all day at 117-119 mph in 4000-5000 feet of air. this is with tea ls6 heads (stock exhaust valves), 232/236 580 580 cam, pulley, and 3:90 gears. i do not have a 90/90 or ewp. i think what these guys are trying to tell you is that dyno numbers are nice but if they cann't back them up at the track, what are they good for? And before you say my car is set up for the strip, believe me it is not. I have everything in my car including extra weight (amps, wirinig for system, ect.), is still a stick, and gets close to 30mpg on the highway. btw, i really doubt you are pushing 40mpg to get 700 miles out of a tank.

 

Compression level really has nothing to do with needing a bigger exhaust system. It is all about volume over time. Increasing the compression level will not change the volume of gases produced. These are things that would warrant a bigger exhaust system:

1) Larger CID motor. You have more physical volume of exhaust gases.
2) Fast revving motor. You will be moving more volume of gases in the same amount of time as a same sized motor that revs slower.
3) Forced Induction. Because of valve overlap from either duration or LSA, both valves will be open in the later stage of the exhaust stroke. Since the manifold is under pressure, it will push more gases( some that have gone through the combustion process and some that has not ) through the cylinder and out the exhaust system.
4) Nitrous Oxide. The combustion process is more complicated than FI, but the end result is that more exhaust gases is produced.

Head and cam packages do increase the volumetric effeciency of a motor, but no where near that of the 4 items listed above. Yes there are some rare cases where a 3" exhaust system and bigger headers will net a small gains on H/C cars, but in general this is not the case. Many years of testing have proven this. That is why the vast majority of people with H/C packages are running running 1 5/8 or 1 3/4 headers with 2 1/2 midsections. There is just no reason to go bigger as it tends to decrease rather than increase torque and horsepower.

Keith

 

I don't buy into their cat back making 7 whp over the Bullets either. There is just no way that an aftermarket cat back for these cars is going to make 7 whp over another cat back which is already straight pipes with resonators.

 

I'm sure the peak numbers are higher, it's bigger pipe. I would be skeptical that the "area under the curve" is greater with a stock or bolt on car.

 

K well I can see 7whp over stock, but 7whp over Bullets? No way.

If it sounds too good to be true, it probably is.

 

Bullets are not that great. They lower restriction by not having much of a muffler, but all C5 exhaust suffer from the same necked down 2.5 inch restriction at the catback. There is more to exhaust then just flow you have pulses to worry about as well. An engine is an air pump and while a bigger displacement engine would probably have more gain going from a 2.5 to a 3 inch catback so will a 346. If you are making enough horsepower you are moving enough air to efficiently use the 3 inch exhaust. Plus it will help the exhaust pulse by not having to change if you have headers and a 3 inch midsection by eliminating the neck to 2.5 inch by the catback.

 

Hey bro, no offense taken at all. I totally appreciate your comments. My drivetrain is an exedy twin plate, carbon fiber drive shaft, DTE stg III diff w/3.42 gears, so she dynos well. With that being said the point of the high numbers is that more can still be had. Every increase from making changes is an improvement. As far as my track times, my shitty 60 ft times (2.11 best) prevent me from getting a good et. However into a stout headwind I trapped 123.6 mph. That should say something for the cars capabilities when she has traction. Now for the gas mileage comment. I didn't get 700 miles from the tank, it was more like 630, and it worked out to an actual consumption of 34.5 mpg, and I literally had fumes left in the tank. She sucked in just over 18 gallons if memory serves. My DIC showed 2 miles until empty. I did it coming back from LG Motorsports in 2006. It was an accident because I missed my off ramp where I had planned to fillup at and decided to see how far I could go before I stopped to fillup.

One more comment about my track times. If I can cut a 1.7x or better on some M/T's what do you think she'll do then ?? 123.6 mph w 2.11 60 into a stout wind. Take away the head wind and give me good 60 I see her hitting 11.4's at 125.xxx What do you think ??

 

right now i think your aluminum flywheel and stock gears are hurting your 60'. there are too many variables to guesstemate an e.t. so i would not even want to try. i do agree with most everyone in this thread, that a 3" dual exhaust will not cause a dramatic difference in times or mph on a heads and cam car over a 2.5".

 

Never said DRAMATIC difference. I doubt much more then 5 maybe 10 if even that much. Lg Motorsports came out with this to eliminate the 2 1/2 inch reduction. Not make dramatic power. If it adds 5-10 to an aggressive h/c car and I was the owner, I'd be happy. Test results coming in mid MAY.

I do appreciate your comments bro. Anytime. Good stuff.

 

The realistic point is running on a track IS real life..

No one runs 1 mile flat out straight up..

Anyway, my car has alot less HP and I run 129 MPH in the 1/4, but I;m sure you can out dyno me...

So you can chirp about having MORE POWER, but what does that get you?
Other cars are FASTER with LESS power.

Point is... what good is MORE power on the dyno?
Its good for nothing!
(except chirping on the internet about dyno #'s)

I think most people would rather DRIVE a FASTER car, than TYPE they have MORE RWHP than the next guy.

 

More live on the track bs from Ellis. Ellis please listen to me ok. I didn't build my car for the track. I've been to the track twice with it in 8 yrs of ownership. Its a weekend toy and trip car because coincidentally it gets the best gas mileage out of my vehicle group. I totally respect your engine build, your gearing, and your amazing 1/4 mile et's and exceptional 60 ft times. In fact I am jealous as hell of your 60 times. At any rate I am asking you to respect that I built the car to be quick and fast. You are very quick, but I am not slow. However I am faster then you'll ever be. Not taking a jab at ya, just pointing out two different goals in mind. I wanted topend and you wanted out of the hole blast off quickness. If and when I rebuild the trans I am considering some custom gearing to make better use of my 6 speeds. Would like to see how fast the car can go with a usable 6th gear.

Another thing Ellis, if you look back at some of your threads you will see how much props I gave you. 10.49 in a high stalled a4 through 3.90's is down right awesome !! Now lets stop the bickering ok.

 

Why can't we all just be friends.....

 

Ellis is a cool guy. I just wish he would realize that I built my car for the topend, and not purposefully to be quick. We are both doing what we want based on our intentions for our cars. He runs low to mid 10's in the quarter, I go 200 whenever I get a chance. To each there own.

I am curious based on the flow improvement of the test car at LGM what it would do for me considering the time it takes to wind out 5th gear, would the better exhaling help??

 

I don't know if it would help you a great deal, it would be safe to say it would not hurt you right? Unless you lost to much back pressure but I don't see that happening.

 

The Big 3 incorporates a muffler into the system thus adding some backpressue I assume. The bullets had no muffler, nothing. Just LOUD !!

 

No problem..

I understand where you're coming from...

Around here, its tough to get out on an open hiway & really let loose for fear of other cars, cops, deer , etc..

I know that around the country guys can take their cars out for miles on out & see literally nothing for hrs on end, so I do get your drift..

I was just trying to say that when I see all these cars w/ high dyno #'s, and big blowers at car shows, I kinda snicker & think its all for nothing...

Locally, there is a fellow with a big azz shiney blower way high up in the air, with like 1800 RWHP & some major meats out back.....
Meanwhile, he's got no bar, nothing....

Just makes me think, its all good for nothing..

Anyway, no issues bro..

Ellis

 

Wow, you both finally came to an agreement.

 

Thank you bro. Any chance of bettering that 10.49 ??? Good luck this year.