Straight pipe is MORE than a sound mod

[SquawkVFR]

Originally Posted by Bo White

I gained nothing on the dyno with my cutouts open.

Me neither. But it sounds so bad ass I don’t care. LOL

[BradoSanz]

Originally Posted by STALKER

I would love for this to be true (getting that much from straight pipes), but unfortunately I just don't think this is even close to possible. Sounds like the Vette might have pooped the bed on your recent run. In any event though, knocking off a C7 with a Gen 5 is nothing to shake a stick at....the weight difference alone kills us. Good win.

Hey there Stalker, I apologize for not replying sooner, life has kept me busy. The C7 is auto, and we raced from 45 on a great road surface so there was no wheelspin involved. It was definitely something that shocked me, so I am currently investing in a dash mount to record runs like these - videos don't lie

Best,

Brado

[BradoSanz]

Originally Posted by Outlaw77

You mean straight pipes that replace the rear mufflers?

Yes. The car was tuned for straight pipes but the dealer had reinstalled factory mufflers "because it was too loud." After putting them back on, I gained a LOT of hp. It was interesting to see.

[BradoSanz]

Originally Posted by Hixson

I think people say that replacing the stock catback with a straight piped aftermarket catback can be expected to gain something 5-10 HP (10 being generous).

To get the 35-40 HP youre talking about you would need to do something like headers and a tune. I would guess that straight pipes and a tune could be good for something like 20? I'm just guessing but I thought a lot of the HP gain of Headers + tune came from the headers.

Is it possible you smoked this vette this time because hes driving a manual and just stinks on that run?

Hey there! Yes, I have full-bolt on with an aggressive cam and a custom 93 octane tune. The car was originally tuned with straight pipes but, as mentioned in one of my previous replies, the dealer I purchased the car from had replaced them with a factory exhaust because it was "too loud." Maybe a better explanation is not that I so much gained HP with straight pipes as I had lost hp with the factory exhaust reinstalled.

[BradoSanz]

Originally Posted by christianchevell

You may have removed some restriction from what ever your old set up was but not so much a gain in power as one pull compared to one other proves little....

It was significant enough that I came here to post about it lol. The way he pulled me before straight pipes was how I pulled him after straight pipes were reinstalled. With full-bolt ons, the aggressive cam, longtube headers and the tune this car has, the power to be gained from the higher exhaust flow was significant.

[BradoSanz]

Originally Posted by InFiD3ViL

I wish he would elaborate on what he means by 'straight pipe'.

When someone says that, I tend to think of long tube headers, without cats, and NO H/X pipe. A true dual setup.

While I am confident I have longtube headers and ported heads, I am not sure whether I have cats or not, to be honest. While, yes, the car is significantly louder with straight pipes, the only way I'd know for sure is to either inspect myself or find the previous owner. In fact, I am still trying to find the previous owner to know exactly what was done to the engine because I should not be pulling a C7 the way I did. I'll take video and do some more runs in Mexico once my dash mount comes in so I can show everyone.

[BradoSanz]

Originally Posted by JerTM

Well, without a dyno to prove your point it's still just anecdotal. I certainly would love to see a simple straight pipe gain that much, but it's just not possible. I wouldn't have put a cam in if it was that easy for so much power.

Edit, what is your definition of "straight pipe"? Long tube headers without cats or muffler? Stock manifold with no cats? Stock manifold, cats, no mufflers?

My apologies, I also have an aggressive cam, longtubes and ported heads in addition to a full bolt-on setup with a custom 93 octane tune. The car was originally tuned with straight pipes involved in the equation but the dealer had them removed due to volume issues. Maybe it is not so much power I had gained from straight pipes as I had lost from having the stock exhaust. Either way, the difference was significant. The car actually felt slower but more consistent in acceleration due to the way the power band changed with straight pipes installed (before, the car felt a lot more "aggressive" above 5000RPMs), so I know that the gains were significant if I felt seat-of-the-pants slower but pulled a C7 below 100 the way I was able to; when previously he was able to walk all over me with my stock exhaust. My brother has been racing and doing PCA events for two decades and is the most consistent driver I know, so he is an excellent partner to compare cars with.

[BradoSanz]

Originally Posted by SquawkVFR

Maybe it sounded like it had more horsepower.

I am not one to be influenced by sound. Instead, I observe the feel of the car (it was wildly different dynamic at full throttle once the straight pipes were installed) and compared acceleration differences. The car felt like a different vehicle with the straight pipes on, and was easier to drive at full throttle due to what was most likely a power curve change as a result of the nature of straight pipes. The fact that I pulled him when before he would walk me on every run we did was too significant to write off as anything else than power gain.

[BradoSanz]

Originally Posted by pyroguy

They say 100 pounds off a car is good for a 0.1 of a second shaved off of your quarter mile E.T. Have you ever weighed the suitcase mufflers? They're way heavier than a muffler setup should be. What you may be experiencing is the loss of 50+ pounds of weight off of your car with the combined volume increase thus making it seem as though your car gained "30-40 hp".

While it was definitely about 45-50lbs of weight loss, that by itself would not be anywhere near enough to PULL a 2015 automatic C7 Stingray below 100, when before straight pipes I would get walked every time and it was CLEAR that the C7 was faster. The only difference that changed between our runs was straight pipe installation. The car WAS tuned with straight pipes involved, but I purchased it from the dealer with stock exhaust due to volume issues as I mentioned in previous replies. Even my brother was impressed but not surprised - when the dealer mentioned they had to remove the straight pipes due to volume issues, he suspected I was losing a lot of HP.

[BradoSanz]

Originally Posted by rontammy0

You will gain zero from a catback or a muffler delete mod.

The results from these runs say otherwise, friend. With full bolt-ons, aggressive cam, longtubes and ported heads plus a custom 93 tune that involved straight pipes in the equation, my car stood to gain significant HP by removing the stock exhaust and putting the straight pipes back on.

[JerTM]

You could verify what you felt with dyno testing, I would be interested to see exactly what is going on.

[BradoSanz]

Originally Posted by JerTM

You could verify what you felt with dyno testing, I would be interested to see exactly what is going on.

I most definitely agree!

[Bo White]

Originally Posted by SquawkVFR

Me neither. But it sounds so bad ass I don’t care. LOL

Now I didnt say "......so I took them off."
Lol

[rontammy0]

Ò

Originally Posted by BradoSanz

The results from these runs say otherwise, friend. With full bolt-ons, aggressive cam, longtubes and ported heads plus a custom 93 tune that involved straight pipes in the equation, my car stood to gain significant HP by removing the stock exhaust and putting the straight pipes back on.

I think whats happened here is that the stock exhaust was somewhere blocked off a bit or plugged up somewhere you cant see it. So once you changed the exhaust it frees up the air flow better for the cam and headers to work properly. You fixed the problem by changing out the exhaust....you went straight pipes but in reality any catback would do. So maybe you gained changing out a bad exhaust for one that wasnt. At least your beating vettes.