Is a Borla Challenge Exhaust system desirable?

[undercover]

I have a set that's new in the box, and I bought it some time ago to put on my Guldstrand GS-80 car (450hp 388ci solid roller L98 derived, single-plane EFI, Traco Headers, etc.).

However, this being a ZR-1 kit, I'd have to hack the front pipes a bit to mate it with my headers.

I have read past posts about the resonator necking down, and it does (I can measure how much but haven't bothered yet).

My two concerns with using this setup are: 1) I'd be destroying a NLA ZR-1 kit that someone may want and 2) I may lose some HP from the high-revving small-block if I use the included center resonator anyway, requiring further modification to the system at which point it's easier just to build one from scratch.

However, if you tell me these systems aren't desirable or worth much, I may throw it on there because it looks great and the quality is nice.

[Gunny]

Originally Posted by undercover

I have a set that's new in the box, and I bought it some time ago to put on my Guldstrand GS-80 car (450hp 388ci solid roller L98 derived, single-plane EFI, Traco Headers, etc.).

However, this being a ZR-1 kit, I'd have to hack the front pipes a bit to mate it with my headers.

I have read past posts about the resonator necking down, and it does (I can measure how much but haven't bothered yet).

My two concerns with using this setup are: 1) I'd be destroying a NLA ZR-1 kit that someone may want and 2) I may lose some HP from the high-revving small-block if I use the included center resonator anyway, requiring further modification to the system at which point it's easier just to build one from scratch.

However, if you tell me these systems aren't desirable or worth much, I may throw it on there because it looks great and the quality is nice.

Yes ... and no -- before you proceed think carefully before hacking anything up since that's not easily reversible.

I recommend that you search these forums using different search criteria - you should find a good bit of info that will help answer your questions.

If memory serves halfway correctly, there were two Borla systems for the ZR-1: one was 1/2 inch piping and the other 3/4 inch. Both had significant necking down at the front of the resonator (hard to see unless you have the front end opened up). I think there was some necking down at the muffler connection, too.

Both systems produced a nice sound (caution: the ZR-1 exhaust sound is highly subjective) but at the expense of mild resonance (drone). The drone could be eliminated by blocking off one tip on each muffler.

I've had each Borla system installed on my '90 with stock manifolds/cats and with S/W headers, with & without cats. I always liked the sound but was always searching for ways to minimize the drone for interstate cruising. When I finally stopped "experimenting" I had tried everything from bone stock to Corsa, Borla, headers, bullet cats, no cats, etc. (you get the idea) to what I ultimately settled on and was very happy with - headers, no cats, stock '96 LT4 cat back system with electric cut-outs in front of each muffler. Mild to Wild and everything in between with a flick of a switch -- absolutely no resonance except when cut-outs were open. Difference on the dyno was approx. 20 HP increase with cut-outs fully opened.

If you're looking for the "perfect" exhaust, good luck. Search on the forums is your friend but the best advice is to be patient and listen to as many systems as you can (be sure to ride in/drive the Z).

[undercover]

Thanks for the quick reply! Yes, I have the challenge setup with 2 3/4" piping. The muffler doesn't look like it necks down, though you can't see the transition between pipe and muffler because it's inside a curve. The resonator is a straight shot, and you can see the pinch from both inside and outside.

The GS80 won't be a freeway cruiser; I hope to get into vintage racing sometime as it's fully set up with cage, fire suppression, etc. The exhaust that's on it now is long tube headers into 3" pipes (with balance tube) into universal magnaflow mufflers. It has ugly tips, ugly welds, and is LOUD.

I'm looking to quiet it down some but not make it quiet. I hate drone but am fine tolerating a bit of drone on this car. I just don't want to attract too much attention driving it on the street.

My other thought was to put a 3" dual in/out xflow 5x8 center resonator like Magnaflow 12469/Jones MF2469 on the current setup just to tide me over and do a custom setup sometime in the future.

The GS80 originally came from Guldstrand's shop with Borla (and why I bought this system), but back in '92 when the car was done, choices were limited...

[GOLDCYLON]

I was just going to say no. Lol GC

[Corvette95]

I have the challenge Borla on my 90 build, I made dual custom 3 inch straight dual resonators instead of the restricted stock resonator. Love the sound and the power and flow is great. They are among the best flowing exhaust Marc H tested **WITHOUT** the resonator. I too had to modify (one) of the header connections to mate up with my OBX headers. (no drone BTW)

[-=Jeff=-]

The challenge exhaust system might be desirable to some, but not very many. I personally like the sound and tips for the challenge system. I had that system on my ZR-1 before I got Corsa (which I no longer have)

I would say if I found a Challenge system for a reasonable price I would consider it again. I am not too concerned about the restriction of the resonator