Interesting chat with Corsa tech line

[DMan]

While deciding on 2.5 or 3 inch track system, I called corsa and got some interesting info I didn't know, figured I'd share.

The hp/tq ratings on their web site are for the 2.5" system 15/20 and that's at the wheels.

The 2.5 & the 3 inch system are the same diameter ... this I didn't know. The 2.5 inch is just the 3 inch with a 2.5 inch coupling so it'll bolt to the stock cats, I thought it was 2.5 inches for the whole system, doh.

So as he told me, technically there's no difference in the hp/tq between the 2.5 or 3 inch, the difference is in whether you cat delete or go RT. He said 3 inch RTs could yield about 6hp at the wheels, but that this change is more about temp & sound, so as he put it - if you want to upgrade in stages, doing the 2.5 inch gives you the 3 inch Corsa Track and using 2.5" RTs guestimate half the yield for fun, so 3hp more instead of the 3 inch 6hp.

He also said that this swap would lower side sill temps by 120-150 degrees! Wow, that's almost reason enough to wap right there.

Anyway, thought I'd share the info. It's helped me decide to go forward with my staged plan, Corsa Track with the 2.5 inch coupling (15hp gain), then if I want more sound & even less heat, upgrade to the 2.5 RTs (3hp more).

Dave.
03 SRT

 

[Racer Robbie]

Quote "He also said that this swap would lower side sill temps by 120-150 degrees!"

I do not see how he can make that claim as outside ambient temperature affects side sill temps.

 

[zorroespanol]

Quote "He also said that this swap would lower side sill temps by 120-150 degrees!"

I do not see how he can make that claim as outside ambient temperature affects side sill temps.

I guess he meant to say that the new system will bring the temp down TO 120-120 degrees, which seems just about right...

That or the new corsas have a freon cooling system.

 

[DMan]

The way he said it I took to mean the temps coming off the exhaust tubing itself would be 120 degrees less hitting the side sills, not the outside sill temp to the touch.

He may have mis-spoke, I may have mis-heard, but that was what i got out of it.

D.

 

[ViperGMC]

You definitely get over 100 deg temp drop in your side sill if you remove the cats. The heat comes from the cats under the sill and with them gone there is nothing to hold the heat. Your exhaust temp is 600+ deg, so yes with the cats gone you very easily get a big drop. The RT cats still hold a lot of heat still, I would say just as much as stock.

 

[Paul Hawker]

With the Corsa track system you also loose all that heat from them crossing over from side to side just behind the passenger compartment, and also loose about 40 lbs from stock.

 

[Hamrhead]

Not trying to go too far off topic, but has anyone ever just replaced the rear cats with straight pipes and retained the stock exhaust?

 

[MikeR]

I didnt know RT made a 2.5" cat. I thought it was only 3" ,therefore the need to go with a 3" Corsa. Regardless, if you are going to go RT cats, why not just do 3" all the way, so you dont have reduced exhaust.

 

[DMan]

MikeR,

Actually the header outlet is 2.5", so you don't reduce going with the 2.5" RTs, the advantage is you go with one hi-flo RT act in place of the 4 OEM cats, then flare out to 3" mufflers with the Corsa. Corsa explained that there might be a 3hp difference in the 2.5" vs 3" RT cats.

I'm thinking about doint the Corsa 1st to see if it's enough for good sound, then have the option to do RTs if I want more, that's the advantage, otherwise I need to do RTs & Corsa all at once due to the 3" coupling not fitting the stock pipes, as our stock pipes are 2.5 inch from the header collector back.

If you know you want to do cats & catback upfront, there's no advantage to go with 2.5 that I'm aware & you get about 3hp more.

D.

 

[SylvanSRT]

btw you can convert your 2.5 into a 3 by cutting the end and having a 3" coupler/or pipe to fill in the small piece the connection

 

[ILLSMOQ]

Actually the header outlet is 2.5", so you don't reduce going with the 2.5" RTs, the advantage is you go with one hi-flo RT act in place of the 4 OEM cats, then flare out to 3" mufflers with the Corsa. Corsa explained that there might be a 3hp difference in the 2.5" vs 3" RT cats.


[/QUOTE]



Really? Who told you that?

I'm thinking about doint the Corsa 1st to see if it's enough for good sound, then have the option to do RTs if I want more, that's the advantage, otherwise I need to do RTs & Corsa all at once due to the 3" coupling not fitting the stock pipes, as our stock pipes are 2.5 inch from the header collector back.

experiment away anything sounds better than stock

 

[stonemaster44]

Hi guys I am new member.I upgraded to 3"corsa &RT cats,I used a2.5" to3" coupling from cats to header collector,the side sill is not as hot as before & the sound is great.

 

[Racer Robbie]

The RT cats still hold a lot of heat still, I would say just as much as stock.

I have to disagree with this statement. On a 80 degree day I could not keep my foot on the aluminum dead pedal with the stock cats and no shoes on. When I changed over to the TR Cats, which eliminate 1 cat, I now can drive barefoot. There is a huge difference. of course all this would also depend on what type of exhaust system you are running. I am running our wrapped AtRo exhaust with the crossover in place. After driving for 2 hours I can rest my hand on the side sills without getting burnt.

 

[MikeR]

MikeR,

Actually the header outlet is 2.5", so you don't reduce going with the 2.5" RTs, the advantage is you go with one hi-flo RT act in place of the 4 OEM cats, then flare out to 3" mufflers with the Corsa. Corsa explained that there might be a 3hp difference in the 2.5" vs 3" RT cats.


D.

I think your wrong on that one. And Im well aware of Hi flos replacing four cats so you only have 2. I have dyno'd with hi flows and without cats. You can do what ya want, but I would go 3".

 

[DMan]

MikeR, sorry, I was just trying to answer a question you asked, why go 2.5, to do it in stages, not everyone has the $2K at one time to do it all at once, why do the RTs if you're doing 2.5, to go hi-flo's. Curious, did you do a stock cat baseline, hi-flo, no cat comparo on the dyno? If so, what did you find?

Bryon Muller told me the header outlet was 2.5", he's a viper tech that was recommended to me in place of Jason Heffner no that he's gone. He came with strong recommendations, but I guess if he's wrong, he's wrong. I haven't taken mine apart yet so I don't know first hand - I asked what I thought would be a good source, but hey, everyone's human. His email quote, "Like I mentioned that factory header collector is 2.5 as well."

Dave.

 

[MikeR]

DMan,
So when I had Corsa with Hi-flows and raced my buddy with Corsa, no cats, he pulled me every time. We would roll on from about 60mph and he would end up a car or two on me. Back when we both just had Corsa we were dead even.

So I dynod differnt times and , while I didnt dyno with each mod specifically, there were only minor changes. So I dyno'd 468rwhp/480rwtq with Hi flows and Corsa.

I removed the cats, Had Corsa and a DC program to help with mixture with no cats and dynod 487 rwhp and 512 rwtq. Big difference was between 3-5k rpm I gained like 30hp and 40+ rwtq. This was same dyno, a week apart.

On a side note, Im no expert, but my friend put in a crossover and it reduced to 2.5" from 3" and he lost power. Where before he would pull me, now I was slightly pulling him. So Im no expert, honestly I dont know much, just what Ive seen in us trying many different things and every weekend going out and racing eachother or dynoing to see what real world difference it made.

 

[JonB]

Hi guys I am new member.I upgraded to 3"corsa &RT cats,I used a2.5" to3" coupling from cats to header collector,the side sill is not as hot as before & the sound is great.

SAM ! Welcome, and glad you like it. I trust LarryM did the install?

 

[JonB]

......Bryon Muller told me the header outlet was 2.5", he's a viper tech that was recommended to me in place of Jason Heffner no that he's gone. He came with strong recommendations, but I guess if he's wrong, he's wrong.

dont blame yourself, muller is wrong. HE is -NO- jason Heffner by any means !!!
But then I estimate 25-35% of the info posted on this site is just plain incorrect..... People MEAN well.....but THE YEAR MATTERS, and often results in FACTS....but the WRONG FACTS !

 

[zorroespanol]

And if I sit my bare butt on the vinyl seat in a summer day it burns....

What the heck are you doing driving barefoot???

The RT cats still hold a lot of heat still, I would say just as much as stock.

I have to disagree with this statement. On a 80 degree day I could not keep my foot on the aluminum dead pedal with the stock cats and no shoes on. When I changed over to the TR Cats, which eliminate 1 cat, I now can drive barefoot. There is a huge difference. of course all this would also depend on what type of exhaust system you are running. I am running our wrapped AtRo exhaust with the crossover in place. After driving for 2 hours I can rest my hand on the side sills without getting burnt.

:

 

[Racer Robbie]

Hey Zorro

Just tried it to prove I could do it barefoot and not get burnt. hell in my Ferrari I had no choice but to drive barefoot with socks on as my feet would not fit the pedals with shoes on.

Your friend,

Robbie