• Sign Up! To view all forums and unlock additional cool features

    Welcome to the #1 Dodge, Jeep and RAM Forum dedicated to FCA owners and enthusiasts. Register for an account, it's free and it's easy, so don't hesitate to join the SRT Forum today!


Getting off the line. Help!

OP
D

Demid22

Active Member
Nurse
10 Second Best E/T
Member ID
#15014
Messages
221
Reactions
81
Likes
27
City
JONESBOROUGH
State
TN
Country
United States
Vehicle
2017 Dodge Challenger Hellcat
Thread Starter #201
Homey thang I didn't know de ice waz gettin off tha line of coke at 3- am. Yea, llike da bettah of a smoken a bannanaher.
.... What? Lol
 


Unholy707

5000 Posts Club
9 Second Best E/T
HFCOTM
Member ID
#11903
Messages
5,079
Reactions
4,205
Likes
402
City
Orlando
State
FL
Country
United States
Vehicle
2015 Dodge Challenger Hellcat
dude, you need to do a compression test, leak down test, pull plugs and check them. What kind of dyno was it? Dynojet? Mustang? We’re the numbers corrected? Dyno numbers are objective
 


OP
D

Demid22

Active Member
Nurse
10 Second Best E/T
Member ID
#15014
Messages
221
Reactions
81
Likes
27
City
JONESBOROUGH
State
TN
Country
United States
Vehicle
2017 Dodge Challenger Hellcat
Thread Starter #203
dude, you need to do a compression test, leak down test, pull plugs and check them. What kind of dyno was it? Dynojet? Mustang? We’re the numbers corrected? Dyno numbers are objective
Dynojet.
 


Unholy707

5000 Posts Club
9 Second Best E/T
HFCOTM
Member ID
#11903
Messages
5,079
Reactions
4,205
Likes
402
City
Orlando
State
FL
Country
United States
Vehicle
2015 Dodge Challenger Hellcat
Gaskets look fine. You’re always going to have oil, just how these engines are
 


Unholy707

5000 Posts Club
9 Second Best E/T
HFCOTM
Member ID
#11903
Messages
5,079
Reactions
4,205
Likes
402
City
Orlando
State
FL
Country
United States
Vehicle
2015 Dodge Challenger Hellcat
Ok, what were the weather conditions? Was that the corrected or uncorrected?
 


Unholy707

5000 Posts Club
9 Second Best E/T
HFCOTM
Member ID
#11903
Messages
5,079
Reactions
4,205
Likes
402
City
Orlando
State
FL
Country
United States
Vehicle
2015 Dodge Challenger Hellcat
The correction factor makes a big difference. Was the car hot? How many pulls?
 


Unholy707

5000 Posts Club
9 Second Best E/T
HFCOTM
Member ID
#11903
Messages
5,079
Reactions
4,205
Likes
402
City
Orlando
State
FL
Country
United States
Vehicle
2015 Dodge Challenger Hellcat
Have you ever had it dynoed before?
 


OP
D

Demid22

Active Member
Nurse
10 Second Best E/T
Member ID
#15014
Messages
221
Reactions
81
Likes
27
City
JONESBOROUGH
State
TN
Country
United States
Vehicle
2017 Dodge Challenger Hellcat
Thread Starter #208
Ok, what were the weather conditions? Was that the corrected or uncorrected?
Corrected. Car wasnt hot. 30 mins cooldown between pulls. 3 pulls. Never had it dynoed before. 1500 ft elevation
 


Attachments

OP
D

Demid22

Active Member
Nurse
10 Second Best E/T
Member ID
#15014
Messages
221
Reactions
81
Likes
27
City
JONESBOROUGH
State
TN
Country
United States
Vehicle
2017 Dodge Challenger Hellcat
Thread Starter #209
Attatched is log from a dyno pull and my dyno sheet
 


Attachments

OP
D

Demid22

Active Member
Nurse
10 Second Best E/T
Member ID
#15014
Messages
221
Reactions
81
Likes
27
City
JONESBOROUGH
State
TN
Country
United States
Vehicle
2017 Dodge Challenger Hellcat
Thread Starter #210
The o rings made into the spacer are extremely flat t. I dont recall them being this flat.
 


Attachments

vortecd

Poster Club Hall of Fame
Premium Account
Donating Member
9 Second Best E/T
HFCOTM
Member ID
#1248
Messages
48,710
Reactions
156,637
Likes
402
City
Middleville
State
MI
Country
United States
Vehicle
2016 Charger Hellcat
The o rings made into the spacer are extremely flat t. I dont recall them being this flat.
@16GoManGoHC2 knows of some replacement o rings he could get you the part numbers
 


OP
D

Demid22

Active Member
Nurse
10 Second Best E/T
Member ID
#15014
Messages
221
Reactions
81
Likes
27
City
JONESBOROUGH
State
TN
Country
United States
Vehicle
2017 Dodge Challenger Hellcat
Thread Starter #212
Inspecting and cleaning spacers and orings. None are broke or cut
 


Attachments

Speedy!

Infomercial Producer
Staff Team
Founding Member
U.S. Marine Veteran
9 Second Best E/T
HFCOTM & HFCOTY
Member ID
#1070
Messages
6,069
Reactions
15,536
Likes
402
City
Murfreesboro
State
TN
Country
United States
Vehicle
2016 Hellcat Go Man Go
I took a look at the log. I don't think there's anything wrong. My opinion is that 2.5 pulley is just not efficient and it's over spinning the blower. Your car made 832rwhp at 1667 mg of aircharge on E85 with 20deg of timing.

My car made 787rwhp at 1611 mg aircharge on 10deg of timing on 93. That was with a 2.72 pulley. Each degree of timing is worth 10 to 11hp give or take so you're right in line with what I'd expect based on the aircharge and blower efficiency characteristics.

I'd go do a 2.72 - 2.75 pulley and live happily ever after (and make the same power) or upgrade to a larger supercharger if you just have to have more. It's either that or start chasing ways to free up the supercharger with a ported inlet, bigger tb, etc but then you're still out of the efficiency range really.
 


OP
D

Demid22

Active Member
Nurse
10 Second Best E/T
Member ID
#15014
Messages
221
Reactions
81
Likes
27
City
JONESBOROUGH
State
TN
Country
United States
Vehicle
2017 Dodge Challenger Hellcat
Thread Starter #214
I took a look at the log. I don't think there's anything wrong. My opinion is that 2.5 pulley is just not efficient and it's over spinning the blower. Your car made 832rwhp at 1667 mg of aircharge on E85 with 20deg of timing.

My car made 787rwhp at 1611 mg aircharge on 10deg of timing on 93. That was with a 2.72 pulley. Each degree of timing is worth 10 to 11hp give or take so you're right in line with what I'd expect based on the aircharge and blower efficiency characteristics.

I'd go do a 2.72 - 2.75 pulley and live happily ever after (and make the same power) or upgrade to a larger supercharger if you just have to have more. It's either that or start chasing ways to free up the supercharger with a ported inlet, bigger tb, etc but then you're still out of the efficiency range really.
Let me pick your brain. When swapping to headers we all know we lose boost due to making the engine more efficient. Therefore we can't really rely on boost numbers to predict power. I was told aircharge is calculated so we cant rely on that either. So how can we calculate and see changes?

My 1/4 mile time is still slow with my modifications says a few on here. How accurate is that?

Jon feels i should be in the 900 range with my setup.

Additionally im only making 16lbs when with my setup we should be in the 18-20 range from what i understand.

I just bought 2150s from him in preparation for the 3.8l whipple but idk when im actually getting that as im about to by land and start a build on our home.

This whole thing has been so frustrating chasing rabbit holes.
 


Speedy!

Infomercial Producer
Staff Team
Founding Member
U.S. Marine Veteran
9 Second Best E/T
HFCOTM & HFCOTY
Member ID
#1070
Messages
6,069
Reactions
15,536
Likes
402
City
Murfreesboro
State
TN
Country
United States
Vehicle
2016 Hellcat Go Man Go
Boost is a "fun" number to reference but isn't a real indication of power/efficiency so when looking at logs I always reference aircharge as that's the actual amount of air in milligrams the car believes is going through the engine. Calculated, yes, but comparing car setups I've found it to be pretty consistent. My 2.7 RE blower with 2.85 pulley and stock lower makes almost 2000 mg as a comparison and about 20psi of boost. The supercharger does have a billlet SDG Motorsports end plate that's opened up a lot compared to stock which helps.

Cheapest and easiest thing would be to change to a larger pulley and see what happens. You might even find someone to borrow a 2.75 from just as a test. Run a log and see what happens. It won't even require a tune change.
 


OP
D

Demid22

Active Member
Nurse
10 Second Best E/T
Member ID
#15014
Messages
221
Reactions
81
Likes
27
City
JONESBOROUGH
State
TN
Country
United States
Vehicle
2017 Dodge Challenger Hellcat
Thread Starter #216
I took a look at the log. I don't think there's anything wrong. My opinion is that 2.5 pulley is just not efficient and it's over spinning the blower. Your car made 832rwhp at 1667 mg of aircharge on E85 with 20deg of timing.

My car made 787rwhp at 1611 mg aircharge on 10deg of timing on 93. That was with a 2.72 pulley. Each degree of timing is worth 10 to 11hp give or take so you're right in line with what I'd expect based on the aircharge and blower efficiency characteristics.

I'd go do a 2.72 - 2.75 pulley and live happily ever after (and make the same power) or upgrade to a larger supercharger if you just have to have more. It's either that or start chasing ways to free up the supercharger with a ported inlet, bigger tb, etc but then you're still out of the efficiency range really.
Let me pick your brain. When swapping to headers we all know we lose boost due to making the engine more efficient. Therefore we can't really rely on boost numbers to predict power. I was told aircharge is calculated so we cant rely on that either. So how can we calculate and see changes?

My 1/4 mile time is still slow with my modifications says a few on here. How accurate is that?

Jon feels i should be in the 900 range with my setup.

Additionally im only making 16lbs when with my setup we should be in the 18-20 range from what i understand.

I just bought 2150s from him in preparation for the 3.8l whipple but idk when im actually getting that as im about to by land and start a build on our home.

This whole thing has been so frustrating chasing rabbit hokes
Boost is a "fun" number to reference but isn't a real indication of power/efficiency so when looking at logs I always reference aircharge as that's the actual amount of air in milligrams the car believes is going through the engine. Calculated, yes, but comparing car setups I've found it to be pretty consistent. My 2.7 RE blower with 2.85 pulley and stock lower makes almost 2000 mg as a comparison and about 20psi of boost. The supercharger does have a billlet SDG Motorsports end plate that's opened up a lot compared to stock which helps.

Cheapest and easiest thing would be to change to a larger pulley and see what happens. You might even find someone to borrow a 2.75 from just as a test. Run a log and see what happens. It won't even require a tune change.

I have a 2.78 i use for 93 tune
 


Speedy!

Infomercial Producer
Staff Team
Founding Member
U.S. Marine Veteran
9 Second Best E/T
HFCOTM & HFCOTY
Member ID
#1070
Messages
6,069
Reactions
15,536
Likes
402
City
Murfreesboro
State
TN
Country
United States
Vehicle
2016 Hellcat Go Man Go
I'd run the 2.78 and get a good WOT log. Will be a good cross check. Should be around the same aircharge as you're seeing now I suspect.
 


OP
D

Demid22

Active Member
Nurse
10 Second Best E/T
Member ID
#15014
Messages
221
Reactions
81
Likes
27
City
JONESBOROUGH
State
TN
Country
United States
Vehicle
2017 Dodge Challenger Hellcat
Thread Starter #218
I'd run the 2.78 and get a good WOT log. Will be a good cross check. Should be around the same aircharge as you're seeing now I suspect.
Thats the plan. Waiting on my brother to help me drop the blower back down. Curiousity... Shouldn't the smaller 2.55 pulley make a greater air charge tho? Sry man... Just trying to learn
 


SilverBillet

3000 Posts Club
Founding Member
Donating Member
Member ID
#1009
Messages
3,860
Reactions
13,598
Likes
252
City
The Villages
State
FL
Country
United States
Vehicle
2021 Jeep GC 5.7 TrailHawk
Doesn’t seem like a 2.55 pulley is that popular among the guys on here who have done pulleys?
 


Speedy!

Infomercial Producer
Staff Team
Founding Member
U.S. Marine Veteran
9 Second Best E/T
HFCOTM & HFCOTY
Member ID
#1070
Messages
6,069
Reactions
15,536
Likes
402
City
Murfreesboro
State
TN
Country
United States
Vehicle
2016 Hellcat Go Man Go
Thats the plan. Waiting on my brother to help me drop the blower back down. Curiousity... Shouldn't the smaller 2.55 pulley make a greater air charge tho? Sry man... Just trying to learn
There is a limit and that limit depends on the supercharger efficiency range. Once you get outside that range more RPM from the supercharger rotors won't mean any more air or any more power. I don't know of anyone still using a 2.5 pulley and those that tested found anything below a 2.70 actually lost power and or went slower at the track. You'll be able to get a log from both of yours and that'll be a good comparison.
 




Top