4.5L Whipple 'Murder Cat'

[Mean Cat]

Currently in the process of finishing tuning on my Hellcat project. Been quite a process over the past year, motivated to see it complete now before winter hits again up north!

Big thanks to Josh and Curt @ Dusterhoff Tuning for helping guide the build in the right direction. Also huge thanks to 'Whip Cat' - 'SRT Stinkeye' and other whipple owners who've done a lot of R&D over the past few years.

Loving the car so far after about 1500 miles of seat time data logging. Night and day difference vs. Stock. First 60-130 hit was like a roller coaster
Car will have a flex 93/E85 map on the 5" pulley @ 16psi and one on E85 only with the 4.5" @21psi. Dyno results will be posted once finished.

Mods:

Engine:
Stock 6.2L/Heads (For this season, plan to upgrade to a 426)
4.5L Whipple Supercharger
Fore Innovations Dual Pump Fuel System w/Rails
FIC 1650cc PnP injectors
Magnaflow Catback
180 Degree Thermostat
ER12S Spark Plugs
Demon Crank Bolt+Double Pinned
Dusterhoff tuning with HP Tuner Software

Brakes/Wheels/Tires/Suspension/Drivetrain:
DSS 3.8" Carbon Driveshaft
DSS 1400HP Axles
Per4mance DIRS Brace
Per4mance Race Brace
Bwoody Rear End Links
Z26 Powerstop Pads
17x10 18x5 Beadlock Drag Pack
MT ET Street R 305/45/17 28x6x18 Sportsman Runners

Exterior & Interior:
SRT Performance Spoiler
Speedtactics Fire Extinguisher kit
View attachment 23421

Nice build & list of parts !
Welcome to Hellcat Nation !

Do you still have the 2.62 ?
A 3.09 & 315's may help too.

 

[MurderCat]

Thanks!

OEM unopened motor, HC converter, and 2.62 (sticking with 2.62 for 1/2 runs)

Seems odd the converter would be a problem on low boost. Don't see upper/lower pulley cars touching those. Could be the whipples torque down low..
With the V86 recall it would eliminate variables and potentially solve the issue? - If a new converter will 100% solve then may have to go that route - Don't know what to do.

Stalling at 70 degree temps+breaking up on Dusterhoff tunes - something is off with HPT wideband cal or there's a mechanical issue, so starting from scratch isn't a bad idea.
Whatever is wrong needs to be fixed.

Feel bad for Curt. - Been working with this build since August 7th. At least we only partially did the 5" and haven't started the 4.5"

Really don't want to spend more on the car this season but whatever needs to be done at this point to get it finished before winter.
Don't want to touch the trans/motor right now. Last thing needed this season lol

 

[Marc W]

Yeah with a completely stock motor and just a mildly pulleyed Whipple you shouldn’t have any converter issues. Just FYI though, when you think about stroking, caming and boosting, the converter is going to need to be addressed. We tried to do a cam’d stroker with the stock HC converter and it was not drivable. Pushing and trying to drive thru the converter every time you came to a stop. That kinda sounds similar to your issue but you obviously have other things going on.

 

[MurderCat]

Plan is a 426 stroker+converter upgrade one day. Looking to enjoy as it sits for a few years now before a serious build.

Zero-flex billet converters sure do look sweet...15% lighter than the Demon's. Capable of holding 2000HP+ - If needed think this is the one.
https://www.hellraisertransmission.com/shop/8hp90-95-232mm-bolt-together-zeroflex-torque-converter/

View attachment 23947

 

[FFBOS]

I don’t know if this might be relevant or not but..... one of the things that was noticeable when I put the Whipple build on the street was how that affects the converter. I was running a Demon converter to address the cam and SC changes but even that was noticeably tight. A lot more brake required to control forward push when coming to a stop and at idle. I wonder if a looser converter might mitigate the bump you’re feeling. You say you didn’t have the problem before the build and maybe the build just requires a different converter rather than messing with the tcm.

I think a lot of that is in the tune. Idle needs to come down.

 

[MurderCat]

Sent HP Tuners an email with everything they asked for (Logs, current tune, scanner/vcm info) Waiting to hear back after data is reviewed if it's the PCM itself vs mechanical issue or tuning related.

Edit: Email from HPT "There is not an issue with the PCM but the way the OS is defined in our software. We are going to be looking more into the issue that is occurring and we will follow up when we have an update." Nothing definitive yet but progress.

V86 Recall Done -> (New downpipes/o2 sensors) -> Shipping to Shop scheduled.

F*** i'm exhausted. It's going down to BPR recommended by DT. Don't want it back in my sight until it's 110%. This Hellcats been puttin' me through hell.
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Anyone who reads this thread hope it saves you a lot of time/$$$$

 

[MurderCat]

Car arrived safe last week rode with a Tesla Model S P100d. Bet that was an awesome sight to see drive down the highway. No update if it needs a converter.


Just grabbed a Killer Chiller race drag system to cure IAT/Coolant temps. Not sure about adding the bigger reservoir. Might see how temps look before deciding if one is needed- unless ya'll that have one on a 4.5L know better.

 

[zhc]

Car arrived safe last week rode with a Tesla Model S P100d. Bet that was an awesome sight to see drive down the highway. No update if it needs a converter.
View attachment 25043 View attachment 25044

Just grabbed a Killer Chiller race drag system to cure IAT/Coolant temps. Not sure about adding the bigger reservoir. Might see how temps look before deciding if one is needed- unless ya'll that have one on a 4.5L know better.
View attachment 25041 View attachment 25045

Highly recommend adding a reservoir, 1.5 - 2 gallons is ideal for 1/4 mile.

 

[Marc W]

Highly recommend adding a reservoir, 1.5 - 2 gallons is ideal for 1/4 mile.

Agree. I went this route because with the shape of this tank, I can run that 2 gallons without uncovering the pump intake and I have the option of still using ice at the track.

 

[FFBOS]

I run a 2 gallon Gearhead tank in the front bumper. For $300 bucks it’s a great fit

 

[MurderCat]

Thanks ya'll. Going to add the coolant tank made by Gearheadfab then.


Should really look into a roll cage/harness system at this point but...street car

 

[FFBOS]

That picture is of the “inter chiller” system from florida, which works worth dick. The gearhead tank sits flush between the front bumper support, it’s slick.

 

[MurderCat]

That picture is of the “inter chiller” system from florida, which works worth dick. The gearhead tank sits flush between the front bumper support, it’s slick.

Glad i went with the killer chiller system, never heard back from that guy in Florida. FI Interchiller would probably be a better option but wanted to stick with a US manufacturer.

Do you happen to have any pictures of the gearhead tank setup?

 

[FFBOS]

Yes

 

[MurderCat]

Thanks for the photos FFBOS.

Wondering if the 13" 'race drag' version will fit in the same location. Going to check what the shop wants to do before ordering the Gearheadfab tank.

I like how 16GoManGoHC mounted the 14" chiller under the driverside light. Also made a custom 1.5 gal reservoir to go under the passenger side. Very clean install.

 

[cole3986]

You guys are crazy, if you want to go race car quick, be a race car, taking street car parts to be a race car will empty your wallets. This is nothing more than another expensive band aide for an ice tank. I was in a bad mood when I made this statement. It is too extreme, based on a really good response below, probably a good mod for a street car that does not want to go with with a dedicated ice tank system.

 

[FFBOS]

Chiller is the best bet for street and strip hands down.

The 13” should fit same location

 

[MurderCat]

From an engineering standpoint i like the chiller concept much better than an Icebox. Both will do the job. I wouldn't call it a band-aid to an ice-box though.

With a chiller you don't have to remove the sound system from the rear (Street car life haha) - No need to fill up with ice packs or dry ice before racing on top of that.

The demon/redeye have a SRT Power Chiller™ from factory. The OEM Engineers must have came to the conclusion it's a quality system. The 2021 Drag Pak is still using an Icebox setup -> those cars don't have an A/C system to begin with for weight savings anyway. For a Street warrior car the chiller is perfect, for MAX-effort removing the A/C system is the most competitive. Comes down to your end goals with the car. Plenty of 8 second cats with the factory A/C system in place. That's all i'd ever want out of this journey. Chasing any faster will put me in the poor house

 

[Primetime Hellcat 17]

From an engineering standpoint i like the chiller concept much better than an Icebox. Both will do the job. I wouldn't call it a band-aid to an ice-box though.

With a chiller you don't have to remove the sound system from the rear (Street car life haha) - No need to fill up with ice packs or dry ice before racing on top of that.

The demon/redeye have a SRT Power Chiller™ from factory. The OEM Engineers must have came to the conclusion it's a quality system. The 2021 Drag Pak is still using an Icebox setup -> those cars don't have an A/C system to begin with for weight savings anyway. For a Street warrior car the chiller is perfect, for MAX-effort removing the A/C system is the most competitive. Comes down to your end goals with the car. Plenty of 8 second cats with the factory A/C system in place. That's all i'd ever want out of this journey. Chasing any faster will put me in the poor house

Check this out. Custom install by SRT AutoWorks.
We can load this bad boy up with lots of ice.
No need to remove sound system with this set up.
Easy to fill up too

 

[cole3986]

From an engineering standpoint i like the chiller concept much better than an Icebox. Both will do the job. I wouldn't call it a band-aid to an ice-box though.

With a chiller you don't have to remove the sound system from the rear (Street car life haha) - No need to fill up with ice packs or dry ice before racing on top of that.

The demon/redeye have a SRT Power Chiller™ from factory. The OEM Engineers must have came to the conclusion it's a quality system. The 2021 Drag Pak is still using an Icebox setup -> those cars don't have an A/C system to begin with for weight savings anyway. For a Street warrior car the chiller is perfect, for MAX-effort removing the A/C system is the most competitive. Comes down to your end goals with the car. Plenty of 8 second cats with the factory A/C system in place. That's all i'd ever want out of this journey. Chasing any faster will put me in the poor house

Great response, however, IATs are much lower using an ice tank IMO. At Dan's event in Kentucky my IATs were below 90 F and it is was super hot day (well over 90 degrees). Maybe I am just ill informed, anyone with the chiller system seeing IATs in the 80s or below on a real hot day?

I went back and modified my previous post, it was too extreme