Getting off the line. Help!

[Demid22]

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]

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

 

[Demid22]

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]

Gaskets look fine. You’re always going to have oil, just how these engines are

 

[Unholy707]

Dynojet.

Ok, what were the weather conditions? Was that the corrected or uncorrected?

 

[Unholy707]

The correction factor makes a big difference. Was the car hot? How many pulls?

 

[Unholy707]

Have you ever had it dynoed before?

 

[Demid22]

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

 

[Demid22]

Attatched is log from a dyno pull and my dyno sheet

 

[Demid22]

The o rings made into the spacer are extremely flat t. I dont recall them being this flat.

 

[vortecd]

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

 

[Demid22]

Inspecting and cleaning spacers and orings. None are broke or cut

 

[Speedy!]

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.

 

[Demid22]

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!]

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.

 

[Demid22]

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!]

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.

 

[Demid22]

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]

Doesn’t seem like a 2.55 pulley is that popular among the guys on here who have done pulleys?

 

[Speedy!]

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.