Budget Street/Autocross/Track 2.5 NC Project!

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Brian
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Re: Budget Street/Autocross/Track 2.5 NC Project!

Post by Brian »

Out with the OLD, in with the FRESH and FAST
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Brian Goodwin
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MitchC635
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Re: Budget Street/Autocross/Track 2.5 NC Project!

Post by MitchC635 »

Expecting the 2.5 planned will be a pretty minor HP gain overall vs the stock 2.0, but a fairly major torque gain up to around 5500 RPM. Would love to see 0-60 times before and after (adjusted for any tire height change) to give a practical idea of how the 2.5 affects everyday performance on the street.
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Re: Budget Street/Autocross/Track 2.5 NC Project!

Post by Brian »

MitchC635 wrote:Expecting the 2.5 planned will be a pretty minor HP gain overall vs the stock 2.0, but a fairly major torque gain up to around 5500 RPM. Would love to see 0-60 times before and after (adjusted for any tire height change) to give a practical idea of how the 2.5 affects everyday performance on the street.
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We don't do street 0-60, too many variables. We will do dyno before/after. Indeed the 2.5 is not so much about horsepower as it is about TORQUE. That low end torque is what pulls you away from stoplights and it's a lot of fun.
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Chuck H
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Re: Budget Street/Autocross/Track 2.5 NC Project!

Post by Chuck H »

One more thought, if you're still looking for potential development projects for NC's, especially 2.5L swaps -- a version of the 1.8" header with longer primaries. Hopefully not PPE-style where it moves the collector and you need a custom shorty midpipe to match it, but more like the JDL 4-2-1 header for the ND, where the primaries curve up with a bit of extra loop before curving down again. Not sure how hard it is to get four 1.8" pipes into that space in the engine compartment (probably REALLY hard), but having a few more inches of primary length would really complement the 2.5L motor's torquier character.

Of course, I always have an ulterior motive, because if that's viable as a product, then duplicating the layout with 1.6" primaries would be easy and awesome for the 2.0L motors, too. And of course it's also always easy to chase dreams with someone else's R&D budget, but I have no idea whether there's enough market to justify yet another header option for our cars. :wink:
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Brian
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Re: Budget Street/Autocross/Track 2.5 NC Project!

Post by Brian »

You guess it, hideously expensive and difficult in the space available for gains in theory that may not be found in reality (once you translate it to something that can actually be installed by regular customers). We actually tested PPE headers all the way up to 1.8 inch primaries, did not beat our current 1.8 shorty on peak hp. Somewhere around here we have a stepped PPE that is 1.75 to 1.8, it obtained the best 2.5 flat torque curve of any header we tested, but total area under the curve really was not any better and given the high costs and high weight relative to the shorty we ultimately decided the shorty 1.8 inch was the best bang for the buck by far. Now that the 1.8 shorty has proven super popular and successful with customer installs, don't see demand to do anything else up there.

In contrast, always has been some demand to do some helmholtz mufflers, and NC has a ton of space back there. So we are playing with drawings and additional design ideas, more to come.
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Re: Budget Street/Autocross/Track 2.5 NC Project!

Post by erikv »

Brian wrote:In contrast, always has been some demand to do some helmholtz mufflers, and NC has a ton of space back there. So we are playing with drawings and additional design ideas, more to come.
This is something I'd be interested in if the resulting product left room to do some effective under diffuser placement. Not sure if the helmholtz chamber has to be round/cylindrical or if you just need a specific volume for tuning. Keeping everything tucked up against the heat shield under the trunk floor is what I'd be looking for. Then maybe you could ask these guys to make something for the NC ;-)

https://www.verus-engineering.com/produ ... r-diffuser
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Re: Budget Street/Autocross/Track 2.5 NC Project!

Post by Brian »

erikv wrote:
Brian wrote:In contrast, always has been some demand to do some helmholtz mufflers, and NC has a ton of space back there. So we are playing with drawings and additional design ideas, more to come.
This is something I'd be interested in if the resulting product left room to do some effective under diffuser placement. Not sure if the helmholtz chamber has to be round/cylindrical or if you just need a specific volume for tuning. Keeping everything tucked up against the heat shield under the trunk floor is what I'd be looking for. Then maybe you could ask these guys to make something for the NC ;-)

https://www.verus-engineering.com/produ ... r-diffuser

I like that idea of doing Verus diffuser for NC.
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Re: Budget Street/Autocross/Track 2.5 NC Project!

Post by erikv »

Brian wrote:
I like that idea of doing Verus diffuser for NC.
I'm sure you have a better feel for how large the potential market is for them. I sent them a quick message from their website this morning about making NC bits and got a "probably not going to happen" reply :(
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Re: Budget Street/Autocross/Track 2.5 NC Project!

Post by DanielS172 »

Those Roadstersport sways probably make street driving a lot more tolerable given the rates on the springs.
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Chuck H
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Re: Budget Street/Autocross/Track 2.5 NC Project!

Post by Chuck H »

erikv wrote:This is something I'd be interested in if the resulting product left room to do some effective under diffuser placement. Not sure if the helmholtz chamber has to be round/cylindrical or if you just need a specific volume for tuning. Keeping everything tucked up against the heat shield under the trunk floor is what I'd be looking for. Then maybe you could ask these guys to make something for the NC ;-)

https://www.verus-engineering.com/produ ... r-diffuser
The shape of the resonator doesn't matter. The frequency is determined by the ratio of the volume of the chamber to the volume of the neck.

That said, esthetics always play a role in car parts, and it seems like especially with exhaust. Everyone expects it to be round or at least oval with rounded corners. If Good-Win were to develop a Helmholtz muffler with a resonator that looked like a cigar box hanging off the side, I'm sure you could count the number of units sold on one hand with 5 fingers left over. :lol:

I suspect that round resonators are the most common because it's easy to make them using the same 4" or 5" diameter tubing used to make straight-through mufflers. But you could do an oval body just as well, and it would probably end up being shorter, since it has a bigger cross section, so you don't need as much length to get the target volume.
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