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If a power loss offsets the benefits of weight loss, then it's pointless to spend a couple grand doing it—whether you notice it or not. And if you don't notice a 10hp loss, you're not going to notice a 30lb reduction in weight on a 3,000+ lb car either. So again... why spend money doing something that has no real-world benefit?
Cool, you ditched 30-40 lbs off the rear of the car. But you lost 5-10hp in the process. And you had to spend money to do it. I'm not saying this what actually happens. But personally, I'd want to know before wasting the time and money. If you can save 30-40 lbs AND not lose any power, then awesome. So far, of the 10 companies that offer side bypasses, not a single one has provided data to support the claims.
Everyone has to feel comfortable with their decision. Would dyno numbers help clarify the picture? You bet. But I don't think we're going to see those.
Not sure I agree with your statement about not noticing the weight reduction if one is tracking the car. Shifting the balance forward, plus getting the added benefit of removing heat build up in the rear tires all adds up. Now if you don't plan on tracking, I'm with ya!
Center Bypass (any type) and stock sides ==> no gains, the anchors are a bottle neck.
Side bypass and stock center ==> no gains, the stock center is the bottle neck. This is from my over a dozen tested exhaust combinations in the 991.1.
Where I gained was on headers (ran 3 different ones) with any combination downstream from the headers, and I also gained on a full larger diameter muffler that ran from the catalytic converters, the Sharkwerks Race Exhaust and the JCR Race pipes both made power.
Soul Performance product quality is beyond impressive.
I'm running their Resonated Tips, instead of my Titanium stock .2 GT3 RS tips. They make a great tone, and the bonus: it takes me 2 minutes to add turndown pipes as I can attach the tips and v-clamps and tighten them by hand. The turndown pipes work, I will be sending John more data from sound measurements, as we will have 2 cars being sound measured running these Soul Performance Turndown pipes and Resonated Tips in a week.
Price may have you think differently but it's top notch quality. Do I dare to go straight pipe is the question. I know it's only for the brave. Anyone in South Florida have them in .2 GT3RS?
If a power loss offsets the benefits of weight loss, then it's pointless to spend a couple grand doing it—whether you notice it or not. And if you don't notice a 10hp loss, you're not going to notice a 30lb reduction in weight on a 3,000+ lb car either. So again... why spend money doing something that has no real-world benefit?
Cool, you ditched 30-40 lbs off the rear of the car. But you lost 5-10hp in the process. And you had to spend money to do it. I'm not saying this what actually happens. But personally, I'd want to know before wasting the time and money. If you can save 30-40 lbs AND not lose any power, then awesome. So far, of the 8 companies that offer valved side bypasses, not a single one has provided data to support the claims.
I'm not picking on Soul, specifically. This applies to anybody selling these things.
You didnt seem to read my post last night on this....what you will notice is less heat into the rear tires causing the psi to raise....plus you will gain a really nice sound too even with that stock rear muffler....then if you want louder just get the Soul rear muffler delete. You will have a nice moduler system.
SCCA Forums has the Soul side muffler deletes with stock titanium muffler in his LG 3RS. I don't think he has a lot of time on it yet though to give you a ton of feedback.
+1 on Soul customer service & quality as I've run their race headers on the 991.1 C4S before - reading up on the GT3 options now - will try to resist the temptation as long as I can.
Separately, I don't understand asking for dyno charts on a catback system where the vendor makes zero power gain claims. Money here would be spent on sound, if there are heat and weight gains, sure I'll take it. You have a customer who recorded the same speed at the end of a straight at a track he frequents - if there was a power loss, he'd likely see it on data. Very slight redistribution of the power curve due to different back-pressure, it's possible. Power gain, not possible, not claimed. Power loss, unlikely. I wish aftermarket exhaust shopping was always this straight forward.
+1 on Soul customer service & quality as I've run their race headers on the 991.1 C4S before - reading up on the GT3 options now - will try to resist the temptation as long as I can.
Separately, I don't understand asking for dyno charts on a catback system where the vendor makes zero power gain claims. Money here would be spent on sound, if there are heat and weight gains, sure I'll take it. You have a customer who recorded the same speed at the end of a straight at a track he frequents - if there was a power loss, he'd likely see it on data. Very slight redistribution of the power curve due to different back-pressure, it's possible. Power gain, not possible, not claimed. Power loss, unlikely. I wish aftermarket exhaust shopping was always this straight forward.
Not concerned with increasing power. I want to see a dyno to see how much power is lost and where. Doesn’t seem unreasonable to me.
and if the mod didn’t affect someone’s track speed/time, then what’s the point again? Side bypass isn’t for sound right? It’s for weight reduction and reducing heat? To what end then if it had no affect on track?
and again I’m not picking on soul. This just happened to be the thread on the first page. Nobody really offers a dyno. Although a few companies do make a power increase claim on their product.
the reason you don’t understand is because you think I’m wanting to increase power. That’s not the case.
and if the mod didn’t affect someone’s track speed/time, then what’s the point again? Side bypass isn’t for sound right? It’s for weight reduction and reducing heat? To what end then if it had no affect on track?
I got the SOUL side bypass for the sound. I personally like it a lot more than the center bypass sound. The 30+ lb weight reduction and reduced heat on the rear tires is just a bonus.
I don’t care if I gained or lost a few watts.
Last edited by Andi; 04-28-2019 at 06:56 PM.
Reason: typo
and if the mod didn’t affect someone’s track speed/time, then what’s the point again? Side bypass isn’t for sound right? It’s for weight reduction and reducing heat? To what end then if it had no affect on track?
I thought the whole point was sound - but if he's reducing heat in that rear wheel well area, he'll likely have benefits unrelated to laptime, most likely better brake temps and better brake wear/feel/performance - and rear tires that'll be less likely to overheat through a long DE session
I thought the whole point was sound - but if he's reducing heat in that rear wheel well area, he'll likely have benefits unrelated to laptime, most likely better brake temps and better brake wear/feel/performance - and rear tires that'll be less likely to overheat through a long DE session
Side bypass is touted as reducing weight and heat, not primarily for sound (nor power gains). But many people focus on the sound aspect.
04-26-2019 | 10:51 AM
