# tune after exhaust?



## Nate (Mar 17, 2010)

is a tune necessary after installing a full exhaust system?? corsa sport to be exact. ive just heard of people getting a tune


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## jpalamar (Jul 22, 2008)

FULL exhaust consists of headers, mids, and catback which you would need to tune for because of the headers flowing better and cats if your catless.

A catback doesn't need a tune. It won't add any preforance to your car unless you at super high HP range. It just changes sound.

Hope this helps.


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## dustyminpin (Jun 19, 2006)

You will get horsepower more so from the tune itself then from the exhaust. I've got Borla. Their numbers show about 5 hp gain over stock, but if you just do a dyno tune on the stock exhaust, you will probably gain more then that. My dyno guy said he can get you about 10 hp over a handheld programmer. All the programmers claim different numbers. Some say as much as 30 but I think that's B.S. Save your money and buy more mods, then get a dyno tune.


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## svede1212 (Nov 1, 2005)

I remember a muffler shop I was at getting a weld touched up at and the guy said he could bolt up a muffler that would give me 40 HP. I got out of there as fast as I could. You shouldn't need a tune changing your pipes and muffler but as said if you haven't gotten one before it will pick up some HP regardless


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## Nate (Mar 17, 2010)

yes all this info helps thanks


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## danfigg (Sep 27, 2009)

*re*

Forgive the F word but back in the day I had a 88 ford mustang GT speed density set up did all the bolt ons and only saw marginal performance gains then I learned that the 89 and up GTs were getting big performance gain because they had the mass air setup and every one was converting ther 86-88 GT to mass air because the speed density set up wasnt adjustable but the mass air set up would compensate for any changes made. So what gives with the GM mass air and why doesnt it compensate for simple bolt ons such as headers and cold air intake. The purpose for mass air is to read how much air is entering so that it can add the proper amount of fuel.----------Danfigg


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## GM4life (Mar 18, 2007)

Nate said:


> is a tune *necessary* after installing a full exhaust system?? corsa sport to be exact. ive just heard of people getting a tune


No. For the car to run optimal yes.


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## 6point0 goat (Aug 1, 2009)

if i install LT's without cats, will my predator tune be ok? i kno u should get it dyno'd but not enough $$ so just askin if my handheld can hold up for a while and still see gains??


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## 6point0 goat (Aug 1, 2009)

6point0 goat said:


> if i install LT's without cats, will my predator tune be ok? i kno u should get it dyno'd but not enough $$ so just askin if my handheld can hold up for a while and still see gains??


anyone?


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## dustyminpin (Jun 19, 2006)

GM High Tech Performance and High Performance Pontiac slap headers on late models all the time and do a before and after dyno without programming the computer just to see what numbers they'll put out. Most of the time, they average gains 15-20 HP WITHOUT a tune. Of course, you get the full blown dyno tune, those gains will go up.


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## PBF Bioset (Apr 25, 2010)

It's not nessesary to tune the engine if somthing is changed at the exhaust-system.
A system with a larger diameter alows a higher flowvolume. That affects ,that more air is filled in cylinders on high rpm's when the mixture formation consists of Lambda =1. 
(over 4000+ circles per second I think)
Means the car will go faster by using its own sofware. 
In lower rpm's, if the gas exchange control sets the mixture to thin it will cause rising consumption of gazoline or, if the system does not react a higher temperature in the cylinder.
But as long as the engine warning sign is off, you needn't worry about that...

greetings


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