Finally getting my ZR-1 back from Corey's!!!

[-=Jeff=-]

Originally Posted by xlr8nflorida

I have a good amount of HP. I don't think you are leaving anywhere near 20 hp on the table especially at the 360hp level. Yes, the Borla restricts as the resonator. However, it sounds good if you like fairly quiet and no resonance. I hate resonance.

The most you are leaving on the table is 5-10 hp on account of the resonator. You can modify your existing reasonator or get an LT-4 resonator. The X pipe will make resonance.

Headers definetly give you 20hp and with a good exhaust you are golden.

To me anyway, unless its 20HP increase or more, the seat of the pants dyno is not affected.

I understand maximizing HP especially cheap hp. Just keep in mind there are trade offs.

I think you can gain 20hp by switching from Borla to B&B which is a bigger less restrictive system and also much louder with more rumble.

The exhaust claims I think are overstated. When the Borla came out in 1990, I have an ad that came from a reputable shop in Florida, I think it was in corvette fever, it says 40 HP increase from exhaust over stock - I'm sorry no way do I believe it. I think half the time you have to cut the claims in half in most people's applications.

Which Borla do you have? I found with my Borla Challenge system I was getting resonance, granted not anything near like B&B but it was there and it was annoying. It was mostly noticeable in the normal range 1500-2000rpm, but with the windows up and AC on.

B&B is louder, magnaflow has more drone then my borla does.

the Corsa has none or next to none with headers. Each person has a different tolerable level for resonance, some more then others

So far I like my Corsa, it is louder then borla the resonance is almost not there

[xlr8nflorida]

From M. Haibeck:

The difference between a stock system on a
93 and straight pipes is about +18 HP

18HP / 5 PSI = About 3.5 HP/PSI of back pressure
reduction

A case in point. The back pressure on a Borla 2.5
inch system is 1.5 psi at peak power.

5 PSI – 1.5 PSI = 3.5 PSI X 3.5 HP/PSI = +12 HP
The bottom line is that there is not too much of a
power difference between aftermarket exhaust
systems.

There is however, a big difference between how
they sound. Let your ears be your guide.

Someone else can pipe in or I'll check my emails. I think it was an article in the newsletter that discusses borla resonator and modifying it or switching to LT4 resonator.

If the truth were known, I think you are closer to losing 5hp then 10hp as a result of the resonator. I can't even really tell the HP difference when the cats are removed. I doubt you would feel much if you went to X pipe, think it would be negligible.

Good Luck

[xlr8nflorida]

Which Borla do you have?

To be honest, I'm not even sure. I think its the first system Borla ever had for ZR-1.

Here is a pic:

[tf95ZR1]

Originally Posted by xlr8nflorida

That is one great looking car...

[EvanZR1]

That's what I have.

[-=Jeff=-]

Originally Posted by EvanZR1

That's what I have.

Both the Regular system and Challenge system look the same but the difference is the Challenge system uses 2.75" pipes instead of 2.5" pipes

I do think the Resonator and mufflers are the same between systems.

[EvanZR1]

Mine's only 2.5". I actually have a 2.75" x-pipe I was going to have Corey put on, but he said the exhaust that's on there is only 2.5

[EvanZR1]

Well, so much for getting my car back. I was just driving along normally, when the car just started running really rough and blowing smoke. Was not on it hard or running it up to red line, and had been running fine before that. Limped it home and will let it cool off so I can take a look at it. So far symptoms are:
running rough, has a loud ticking, is blowing smoke and there is an oil leak on the driver's side dripping onto the header. Something else that was weird is that it would occasionally run better briefly on the drive home (under light acceleration over about 2,000rpm).

The ticking sounds like when I had a header gasket blow out on my LT4 Firehawk, but that did not cause rough running like this. I'd think a burnt/shorting plug wire, but they don't go anywhere near the headers. Maybe a fouled plug?? But what about the smoke?

Needless to say I'm really irritated at this point.

[sammy]

i came up with a system that dropped my et by 2 tenths and gained 1.7 mph at the strip over the corsa . my white car is a callaway 475 s natural zr1 with headers . the nice thing is its as quiet as the corsa at cruise. and has a very nice tone when your on it . it cost me 400 for everything . i started with a stk zr1 exhaust .built a ladder style crossover ,got rid of the resonator (put in sections of 23/4 pipe) then bought 2 dyno max super turbo 3 in mufflers with dual exits put on the zr1 tips painted it black and it looks stk .super turbo mufflers 120 for both 150 for the zr1 exhaust and 130 to have a muffler guy put it together . there are videos of the car at the strip with this setup on it . sorry i dont know how to post them here but if you pm me your email i can send them to you from u tube. bill boudreau drove the car with this setup and he loves the sound ..its nice not to spend over 1000 dollars for a exhaust.its not stainless but it should last a good long time .

[sammy]

are your coils the stk ones that the car came with . i had 1 post go out on one of my coils and it acted just like your is doing now .