Jared's 2015 Challenger Hellcat Build

[Jroc]

Hey guys, I'm new here and thought I'd start a build thread for my car.



This is my 2015 Challenger Hellcat I bought about a year ago. When I bought the car it had Longtubes, catless mids, 3.09 gears, DSS aluminum driveshaft, diff brace, Fore fuel hat with twin hellcat pumps, ATI 10% balancer, Alky control meth kit, ID1300 injectors, and a 4.5 Whipple. You know what they say about buying someone else's project, I spent the rest of the season trying to get the car sorted with the help of Mike @ostmike (remotely), and during that time added a Whipple big oval throttle body, Fore fuel rails, flex fuel sensor and gauge along with a few other things. The car suffered the weirdest issues, and after finally getting the car flashed back to stock with a WiTech and giving Mike a stock file to tune off of, instead of the mess of a tune that was in the car when I bought it we finally had it up and running. Right when we finally got it decently dialed in, the season ended.



I got the car out to the first track rental this year, and the car ran strong first hit, going 9.82@143 MPH with minimal cool down. I sent the log to Mike who sent me a revised tune with more power in the leave and more timing throughout as I was running a 50/50 93 Octane and VP Q16 mix, but unfortunately we never got to see what that would do as the blower ate a bolt immediately after my burnout.



Upon tearing it down it appears that whoever installed the blower initially didn't locktite the bolts holding the intercooler to the lower manifold, they loosened off, and the one directly under the bypass valve got sucked up through the bypass, and directly into one of the rotors. I checked the adjacent bolt, and it was loose as well. I had originally planned on building a stroker motor last winter when I first bought the car but after fighting all year to get it running right I wanted at least one season with it before we started from scratch. I have a Whipple 3.8 on the way to replace the Whipple 4.5 that was on it and will just have to keep it turned way down this year to keep the bottom end in tact. Barring any unforeseen circumstances, the car will get a 426 or 411 stroker over the winter, along with a TH400 and a cage.

Current parts on the way for the car:
Billet Pre-Production Whipple 3.8 Hellcat supercharger
Nick Williams 130mm throttle body
Legmaker Whipple 3.8 intake
BMR cradle lockouts
AAD drag pack kit
15 inch rear conversion
Billet specialties wheels
Anderson composites Demon cowl hood (to fit the blower)
AWE Touring resonated exhaust
Other misc crap that I forget

Parts here to be installed:
Per4mance development DIRS diff brace
Per4mance development race brace
GeForce Outlaw axle shafts

Happy to answer any questions and will keep this thread updated as parts arrive and are installed.

 

[BULL]

Watching

 

[fumanchu182]

Sorry to hear about the bolt issue. Subbed!

 

[Mean Cat]

Hey guys, I'm new here and thought I'd start a build thread for my car.

View attachment 105775

This is my 2015 Challenger Hellcat I bought about a year ago. When I bought the car it had Longtubes, catless mids, 3.09 gears, DSS aluminum driveshaft, diff brace, Fore fuel hat with twin hellcat pumps, ATI 10% balancer, Alky control meth kit, ID1300 injectors, and a 4.5 Whipple. You know what they say about buying someone else's project, I spent the rest of the season trying to get the car sorted with the help of Mike @ostmike (remotely), and during that time added a Whipple big oval throttle body, Fore fuel rails, flex fuel sensor and gauge along with a few other things. The car suffered the weirdest issues, and after finally getting the car flashed back to stock with a WiTech and giving Mike a stock file to tune off of, instead of the mess of a tune that was in the car when I bought it we finally had it up and running. Right when we finally got it decently dialed in, the season ended.

View attachment 105776

I got the car out to the first track rental this year, and the car ran strong first hit, going 9.82@143 MPH with minimal cool down. I sent the log to Mike who sent me a revised tune with more power in the leave and more timing throughout as I was running a 50/50 93 Octane and VP Q16 mix, but unfortunately we never got to see what that would do as the blower ate a bolt immediately after my burnout.

View attachment 105777

Upon tearing it down it appears that whoever installed the blower initially didn't locktite the bolts holding the intercooler to the lower manifold, they loosened off, and the one directly under the bypass valve got sucked up through the bypass, and directly into one of the rotors. I checked the adjacent bolt, and it was loose as well. I had originally planned on building a stroker motor last winter when I first bought the car but after fighting all year to get it running right I wanted at least one season with it before we started from scratch. I have a Whipple 3.8 on the way to replace the Whipple 4.5 that was on it and will just have to keep it turned way down this year to keep the bottom end in tact. Barring any unforeseen circumstances, the car will get a 426 or 411 stroker over the winter, along with a TH400 and a cage.

Current parts on the way for the car:
Billet Pre-Production Whipple 3.8 Hellcat supercharger
Nick Williams 130mm throttle body
Legmaker Whipple 3.8 intake
BMR cradle lockouts
AAD drag pack kit
15 inch rear conversion
Billet specialties wheels
Anderson composites Demon cowl hood (to fit the blower)
AWE Touring resonated exhaust
Other misc crap that I forget

Parts here to be installed:
Per4mance development DIRS diff brace
Per4mance development race brace
GeForce Outlaw axle shafts

Happy to answer any questions and will keep this thread updated as parts arrive and are installed.

Following.
You do have the Fastest color to start with.

 

[Jroc]

Thanks guys. Parts are scheduled to begin arriving this week, hopefully get some good wrenching on it next weekend.

 

[Marc W]

Some things to consider from one who has wondered down this path. You will need to decide what you want to do as far as your driveline goes. You mentioned the T400. I’ll assume you know about the hurdles that you will have to deal with to do that with the factory computers being converted from auto to manual. At the stroker/3.8 power level you’re looking at, you will need either the T400 or one of the high end hp90 builds available now. Both of those will require a proper converter to go with. Then there’s the rear end. That’s a whole other conversation and what you should do depends on your trans choice (gear ratios). I look forward to watching your progress 👍🏼

 

[Jroc]

Some things to consider from one who has wondered down this path. You will need to decide what you want to do as far as your driveline goes. You mentioned the T400. I’ll assume you know about the hurdles that you will have to deal with to do that with the factory computers being converted from auto to manual. At the stroker/3.8 power level you’re looking at, you will need either the T400 or one of the high end hp90 builds available now. Both of those will require a proper converter to go with. Then there’s the rear end. That’s a whole other conversation and what you should do depends on your trans choice (gear ratios). I look forward to watching your progress 👍🏼

I appreciate it man. When the TH400 goes in is when the car will likely be going to a Holley Dominator setup. Moser makes an interesting solid axle kit that is on my radar, but might be overkill. The other route is one of the bolt in 9 inch IRS kits. I'm going to see how things shake out over the course of this year and make a decision from there. Gear ratio and converter I'll have a better idea of when things start coming together.

 

[Marc W]

Try to not buy stuff that ends up getting replaced later. That’s a real budget killer. If you are planning on the Dominator, don’t waste money converting the factory pcm to use the 400 and then end up with the Dominator later. Having a plan (and budget) to go straight to the end game without buying anything that will be replaced will save a lot of money. If you go with the 400, I would recommend the DSS rear conversion as your budget option. Much stronger Pro Gear and a 35 spline spool or Wavetrack with matching axles are in my opinion as good as it gets if you’re going to stay with the IRS. You will be able to match your overall gear ratios with the properly geared 400. If you’re working with OST, they can set you up with a Coan. The trans is custom built so make sure you get 1st and 2nd gear ratios to work with the rest of the specs. I’m running a 3.40 rear gear in my car. If I was running a factory rear I would be stuck with a 3.09 which is far from optimal with the 400 and a 30” tire.

 

[Speedy!]

Will be fun to follow a long. I've heard of more than one of those 4.5L Whipples eating bolts from random places unfortunately. Buddy of mine had that happen only the bolt made it past the rotors and trashed his brand new 426

 

[Marc W]

Will be fun to follow a long. I've heard of more than one of those 4.5L Whipples eating bolts from random places unfortunately. Buddy of mine had that happen only the bolt made it past the rotors and trashed his brand new 426

Yep. It was a concern back when the 4.5’s were starting to show some promise. Apparently a number of those got out of Whipple without those screws getting the locktite they needed. Remember WhipCat here? He had one come loose and it got kicked back into the throttle body on shutdown and lodged in the blade. He lucked out. After seeing that I pulled mine apart and did what was necessary.

 

[Speedy!]

Where has Whipcat been?

 

[Marc W]

Where has Whipcat been?

He popped in a while back. He bought a TRX and he and his dad were doing some track racing Mustangs. I think he still has the Hellcat. We had some good times racing the half mile and eating Mexican food in Arizona.

 

[Unholy707]

Had a hate/hate relationship with my 4.5, horribly designed manifold in and out

 

[Marc W]

Had a hate/hate relationship with my 4.5, horribly designed manifold in and out

Spacer to increase plenum volume and some minor tweaking to the intake and they work great. 😝

 

[Unholy707]

Spacer to increase plenum volume and some minor tweaking to the intake and they work great. 😝 View attachment 105849

I wanted to do this to mine for the rear plenum, saw it on a green challenger hellcat years ago

 

[Unholy707]

Shouldn’t have to modify a $7k blower/throttle body though

 

[Marc W]

I wanted to do this to mine for the rear plenum, saw it on a green challenger hellcat years ago

That was the blower on the Grinch. We still have that car and it will be coming out of retirement next year with a 3.8. It was the fastest full weight Hellcat in the country 5 years ago. Ran 9.1 with that Whipple when nobody else in the country was out of the 9.4’s yet. Nichole was 18 when she was unbeatable in that thing.

 

[Unholy707]

That was this blower on the Grinch. We still have that car and it will be coming out of retirement next year with a 3.8. It was the fastest Hellcat in the country 5 years ago. Ran 9.1 with that Whipple when nobody else in the country was out of the 9.4’s yet. Nichole was 18 when she was unbeatable in that thing. View attachment 105855

Thought it looked familiar!! Didn’t know it was yours!

 

[Unholy707]

I used 1/4” spacers on my front k member to drop it engine down low enough for 4.5 to clear hood with FI spacers, only way I got manifold #2 to seal. Still had to remove the flame retardant on the hood and notch part of it by the driver side washer hose. My wiper arm is still bent from original install lol

 

[Unholy707]

I still have the spacers, makes changing plugs a bit easier because it drops the passenger side out of the way of the PDC wires/plastic shroud covering them on passenger side strut tower. Was going to take them off but they level the rake of the car out which in my mind says is better for weight transfer but who knows