Another hellion build with questions for fellow members...

[Zrussian13]

Hey guys! Finished my hellion street sleeper kit 2 weeks ago and completed remote tuning shortly after. Car runs great! Feels totally stock out of boost, drivability is spot on but once you get on it the car screams! Base turbos with jms bap and dw95s running on 5lb springs. Hellion says they put 7lbs to the engine. Tuner agreed I'm sitting at 6-7lbs but my boost gauge is on backorder so I cant monitor yet. Got a couple questions....

First off exhaust- I purchased the borla S-type with the kit. It showed up early so I slapped it on and it was way too loud for me! I went ahead and ordered the 60661 borla resonator and it did the job quieting it down but the resonator is 2.5" and it necks down to 2 1/4" at the connects. When I put the hellion kit on I cut the connects off so it only bottle necks down to 2.5". I'd like to change out the resonator so it's 3" all the way through but I need ideas. I'm trying to keep it quiet as possible so some form of 3" resonator would be ideal. I looked at vibrants and don't have the room. I've found some bullet type resonators that will fit but not sure how much they will help. Found a magnaflow xpipe muffler that matches the borla resonator size that looked promising but then I found sites that say it's not a true x pipe and goes through a single 3" y pipe. Any input would be appreciated.

Secondly, I drive a lot. I put 1,000 miles on the car since I finished everything a week and a half ago. I have a work truck I could drive but I really enjoy opening the gt up on a daily basis so I only drive the truck when necessary. I probably get into boost good about 5-6 times a day at least. Running on 91 out here plus 1/3 bottle of boostane per tank. Am I at a relatively safe level of boost? Or should I be cautious? I know you have to pay to play and I'll build the motor when the time comes but I'd like to ride the stock block out as long as possible.

Almost forgot... 2019 gt pp1, kit went on at 48.6k miles. Sitting right under 49.6k when I got home from work today.

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[GuardGT]

91 and torco/boostane should be absolutely fine at 6-7lbs, hell I’m running 91 and torco at 11-12lbs, 18 degrees and she loves it. Just watch out for knock from a tank of crap gas, it happens.

as for exhaust, I have gone through 10+ muffler combos trying to find something Mild I’m happy with. Corsa, flowmaster, Jones, and some off the wall combos too. I haven’t shared my current setup on here but it sounds unlike any other coyote ive heard and it’s.... actually pretty quiet. Deep and bassy, zero rasp, zero drone, and literally no high pitch sounds at all. It’s a bit louder at idle than the stock mufflers, but is about the same while cruising.

right before I switched to my current setup I had no cats with Jones turbine resonators welded in the area of the cats, an x pipe and stock non-active mufflers. Made a little noise but nothing crazy at all. I have videos of that setup if you want to hear it. The resonators knocked a little rasp off, brought the sound down a few db, but not as much as I wanted.

Then I said screw it and got the 2.5” borla pro xs dual in/out muffler and installed it in place of my x pipe, then ran 2.5” pipes past the gas tank to dumps because I didn’t want tail pipes. I was blown away, the car is mild, tone is great, and cold starts are way more mild than they were before even with stock mufflers. I can get you a video if you’d like, and yours will be even quieter because of the turbos.
Edit: I just looked and the borla pro xs doesn’t come in 3” sadly. And as for resonators, the shorter they are the more useless they are. You need longggg resonators to really make a difference. That said, the quietest shorter ones I’ve seen are the vibrant ultra quiets.

 

[wazslow]

Did you opt for the loudvalve cutouts? Thats what I have on mine with a full 3 inch exhaust into a Gibson catback (was on the car before I installed the turbo setup). Pretty quiet when cruising and the cutouts open up under boost.

 

[Slopoke]

You might want to fit a Magnaflow 3" dual in and out muffler. I remember someone on this forum using it as a resonator.



https://www.magnaflow.com/collections/3-inch-inlet-by-3-inch-outlet-mufflers

 

[Zrussian13]

91 and torco/boostane should be absolutely fine at 6-7lbs, hell I’m running 91 and torco at 11-12lbs, 18 degrees and she loves it. Just watch out for knock from a tank of crap gas, it happens.

as for exhaust, I have gone through 10+ muffler combos trying to find something Mild I’m happy with. Corsa, flowmaster, Jones, and some off the wall combos too. I haven’t shared my current setup on here but it sounds unlike any other coyote ive heard and it’s.... actually pretty quiet. Deep and bassy, zero rasp, zero drone, and literally no high pitch sounds at all. It’s a bit louder at idle than the stock mufflers, but is about the same while cruising.

right before I switched to my current setup I had no cats with Jones turbine resonators welded in the area of the cats, an x pipe and stock non-active mufflers. Made a little noise but nothing crazy at all. I have videos of that setup if you want to hear it. The resonators knocked a little rasp off, brought the sound down a few db, but not as much as I wanted.

Then I said screw it and got the 2.5” borla pro xs dual in/out muffler and installed it in place of my x pipe, then ran 2.5” pipes past the gas tank to dumps because I didn’t want tail pipes. I was blown away, the car is mild, tone is great, and cold starts are way more mild than they were before even with stock mufflers. I can get you a video if you’d like, and yours will be even quieter because of the turbos.
Edit: I just looked and the borla pro xs doesn’t come in 3” sadly. And as for resonators, the shorter they are the more useless they are. You need longggg resonators to really make a difference. That said, the quietest shorter ones I’ve seen are the vibrant ultra quiets.

11-12 lbs is awesome on 91. How long have you been running that much boost?

I do love the sound of my 2.5 borla resonator. I wish they made a 3" version. I got under the car this weekend and measured hoping the vibrant ultras would work but not much room on the S-type to fit them in.

 

[Zrussian13]

Did you opt for the loudvalve cutouts? Thats what I have on mine with a full 3 inch exhaust into a Gibson catback (was on the car before I installed the turbo setup). Pretty quiet when cruising and the cutouts open up under boost.

My original plan was loud valves but unfortunately hellion dropped the option about 2 months before I was ready to buy.

 

[Zrussian13]

You might want to fit a Magnaflow 3" dual in and out muffler. I remember someone on this forum using it as a resonator.



https://www.magnaflow.com/collections/3-inch-inlet-by-3-inch-outlet-mufflers

I'm looking at the magnaflow dual in/ out but it has an internal x pipe. I've heard several places online that it's not a true x pipe but a double y that necks down to one 3" in the middle. I'm waiting on a reply from magnaflow to confirm which it is.

 

[Slopoke]

If you click on the video in the upper r/h section of the webpage. It describes the inner construction.

https://www.magnaflow.com/products/...dualdual-straight-through-performance-muffler

 

[Zrussian13]

If you click on the video in the upper r/h section of the webpage. It describes the inner construction.

https://www.magnaflow.com/products/...dualdual-straight-through-performance-muffler

Thanks. I still want confirmation from them prior to ordering. Borla lists the 60661 as a 3" resonator but the only thing 3" is the connects coming out the back.

 

[Slopoke]

Thanks. I still want confirmation from them prior to ordering. Borla lists the 60661 as a 3" resonator but the only thing 3" is the connects coming out the back.

Yeah, I was fooled by the Borla stating 3" too. I got the S-Type cat back and paired it with the Borla Resonator. I did this, because the S-Type is 3" and since I was putting a supercharger on, I'd want a 3" system compared to the Borla Touring at 2.5", for more flow.

 

[Chris Barnes]

If you're in Phoenix like me, I'd say you are right in the sweet spot with boost and octane. Our fuel here is HORRIBLE. Lund say's it's among the worst which is why I could only run 8.5 psi and like 13-14 deg of spark advance without significant knock. I'm running a Procharger on 2018 GT, but not too far off from your setup in reality. I've found that Chevron fuel makes the knock sensors the happiest, although happy is a relative term here in AZ. I'm now running a meth system and see 18-21 deg of spark advance FWIW. I've been running this identical setup for the better part of 3 years and no issues. Not daily driven, but gets driven several times a week and an occasional road trip. Hit me up if I can help.

 

[Zrussian13]

If you're in Phoenix like me, I'd say you are right in the sweet spot with boost and octane. Our fuel here is HORRIBLE. Lund say's it's among the worst which is why I could only run 8.5 psi and like 13-14 deg of spark advance without significant knock. I'm running a Procharger on 2018 GT, but not too far off from your setup in reality. I've found that Chevron fuel makes the knock sensors the happiest, although happy is a relative term here in AZ. I'm now running a meth system and see 18-21 deg of spark advance FWIW. I've been running this identical setup for the better part of 3 years and no issues. Not daily driven, but gets driven several times a week and an occasional road trip. Hit me up if I can help.

Yeah I only use chevron or shell. They seem to be the best options out here. I was surprised during tuning I was told I could add a few lbs if I wanted. Up to 9! I think I'll enjoy it where it's at for now and finish working on tires and suspension before I think about any more boost.

 

[GuardGT]

11-12 lbs is awesome on 91. How long have you been running that much boost?

I do love the sound of my 2.5 borla resonator. I wish they made a 3" version. I got under the car this weekend and measured hoping the vibrant ultras would work but not much room on the S-type to fit them in.

ive Been running it for 6+ months, and a few track days. Done a best of 9.90 @144, and I run 100 octane the track to be safe. I also have a methanol kit on the car... it’s not tuned for the meth but it staves off knock on my hot tune with 21 degrees of timing. I’m not taking any chances. Car is super happy and the tune is still quite mild, but the stock trans is taking a beating.

 

[onefastmf]

My original plan was loud valves but unfortunately hellion dropped the option about 2 months before I was ready to buy.

I got loud valves I'm not super crazy about and be down for some type of trade, LMK

 

[wazslow]

I got loud valves I'm not super crazy about and be down for some type of trade, LMK

Just curious, what don't you like about them? They are one of my favorite things about the setup.

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