OST Street Hellcat "Project"

[Speedy!]

That's news to me, 1000rwhp on 93 octane. Is that straight 93 no added anything like meth inj etc? If any o'l fuel could be used I'm curious why higher power cars can't run 87.

 

[Jon-MooredPerformanceLLC]

That's news to me, 1000rwhp on 93 octane. Is that straight 93 no added anything like meth inj etc? If any o'l fuel could be used I'm curious why higher power cars can't run 87.

@Bowlerguy92 uses my cam and hatermakers engine. Hes running a 2.85 upper on his 2.7 blower. Which typically way to much boost for 93. But on the 426 and the custom spec cam I think he makes 13 or 14 psi now and makes around 850 wheel on pump 93. I would have to go back and look.
@Jack_Toepfer My car went from around 22.5 psi to 17.5 psi when i went to a 426 and my custom spec cam. But I only run e85.

 

[Jon-MooredPerformanceLLC]

That's news to me, 1000rwhp on 93 octane. Is that straight 93 no added anything like meth inj etc? If any o'l fuel could be used I'm curious why higher power cars can't run 87.

Im not saying anything about the 1000rwhp because i dont know anyone running that much. But with turbos I could see 900s maybe being possible with the right setup.
I guess I will also put it this way then why dont you have to pulley up to flow less air when going to a 426 or better flowing heads if it is an air flow limit for the octane?

 

[Bowlerguy92]

2.75 pulley now @ 15 PSI

@Bowlerguy92 uses my cam and hatermakers engine. Hes running a 2.85 upper on his 2.7 blower. Which typically way to much boost for 93. But on the 426 and the custom spec cam I think he makes 13 or 14 psi now and makes around 850 wheel on pump 93. I would have to go back and look.
@Jack_Toepfer My car went from around 22.5 psi to 17.5 psi when i went to a 426 and my custom spec cam. But I only run e85.

 

[Speedy!]

Im not saying anything about the 1000rwhp because i dont know anyone running that much. But with turbos I could see 900s maybe being possible with the right setup.
I guess I will also put it this way then why dont you have to pulley up to flow less air when going to a 426 or better flowing heads if it is an air flow limit for the octane?

I think the real answer is because of variables. We all know higher octane has detonation resistance which I "think" is the real culprit to our limit, so reducing other factors that induce knock like heat, dynamic compression, etc influence where you end up. However, the risk isn't worth it IMO trying to get to the bleeding edge of a fuel's limit.

The people I know of that claim these big power numbers on "pump gas" always have something in the background they don't disclose until pressed like meth injection as an example. Some also hang a 1000hp dyno sheet from their car hood at the cruise in, but if you talk to the shop they'll say "well, we added a splash of race fuel for the dyno and turned it down afterward for street use".

 

[vortecd]

I think the real answer is because of variables. We all know higher octane has detonation resistance which I "think" is the real culprit to our limit, so reducing other factors that induce knock like heat, dynamic compression, etc influence where you end up. However, the risk isn't worth it IMO trying to get to the bleeding edge of a fuel's limit.

The people I know of that claim these big power numbers on "pump gas" always have something in the background they don't disclose until pressed like meth injection as an example. Some also hang a 1000hp dyno sheet from their car hood at the cruise in, but if you talk to the shop they'll say "well, we added a splash of race fuel for the dyno and turned it down afterward for street use".

So many claim they are on pump 93 but they are using octane booster to be safe so it isn't really 93

 

[Jon-MooredPerformanceLLC]

I think the real answer is because of variables. We all know higher octane has detonation resistance which I "think" is the real culprit to our limit, so reducing other factors that induce knock like heat, dynamic compression, etc influence where you end up. However, the risk isn't worth it IMO trying to get to the bleeding edge of a fuel's limit.

The people I know of that claim these big power numbers on "pump gas" always have something in the background they don't disclose until pressed like meth injection as an example. Some also hang a 1000hp dyno sheet from their car hood at the cruise in, but if you talk to the shop they'll say "well, we added a splash of race fuel for the dyno and turned it down afterward for street use".

I can agree with that. Then say it was for safety and they didnt make a tune change so it doesn't matter but it does. I guess the point I am trying to make is yes there are a lot of factors. But also the bleeding is also pushed farther away. For the people who want more power on 93 a properly setup 426 is a great way to accomplish this and that it isn't air flow that causes the 93 limitation.

But all in all this is the nice thing about forums allowing us to have these conversation.

 

[Unholy707]

I can agree with that. Then say it was for safety and they didnt make a tune change so it doesn't matter but it does. I guess the point I am trying to make is yes there are a lot of factors. But also the bleeding is also pushed farther away. For the people who want more power on 93 a properly setup 426 is a great way to accomplish this and that it isn't air flow that causes the 93 limitation.

But all in all this is the nice thing about forums allowing us to have these conversation.

So 2” primary long tube headers, full ported 2.4, 108mm throttle body, same pulley 2.69, stock cam/heads. Would you expect to see an improvement here, from your experience? Or is a cam really needed to take advantage of the increase in airflow (ability) both in and out?

 

[Jack_Toepfer]

Like I said, I wouldn't recommend 1000rwhp with a Hellcat, certainly not with a screw blower and stock displacement.

How does the new ZR1 do it? It has a DOHC 5.5L flat plane v8 with twin turbos that sings up to 7000rpm. Direct and port injection. I'd be surprised if it makes 1krwhp, but I don't doubt that the rwhp numbers will align with over 1kchp.

If you want to make big power on 93 you need big displacement. Here is a HEMI... one I've been following for a while. This one isn't 1k wheel... but it is 2500+ at the crank. It's going into a boat that will run 93 octane. Steve recommends a splash of octane booster if he wants more power or prolonged runs at max hp... but he made it and shipped it on 93. Don't think this could be toned down to 1500chp and be safe all day? I'm sure it could.

Worth watching the whole series, but I put the video right where it needs to be.

 

[ostmike]

I've heard the rumor that allowing better flow and reducing boost is somehow "safer". In my unprofessional opinion I don't think that's s measure of safe or not safe. More air flow is more air flow and the as far as the tuning is concerned it doesn't see boost pressure at all, it sees air flow in mg / charge. More mg = more power.

Mike can enlighten us on this I'm sure

Something else to keep in mind concerning aircharge. On the Hellcat (and most newer vehicles from all the major manufacturers) the aircharge value is actually based on injector definition, torque modeling and VE. If a vehicle is modified from stock and any of the previously mentioned values are modified the "calculated" aircharge can be impacted in an undesirable way. This is why proper injector definitions are so critical as well as VE settings (when disabling ANN) as well as other table definitions.

 

[ostmike]

I can agree with that. Then say it was for safety and they didnt make a tune change so it doesn't matter but it does. I guess the point I am trying to make is yes there are a lot of factors. But also the bleeding is also pushed farther away. For the people who want more power on 93 a properly setup 426 is a great way to accomplish this and that it isn't air flow that causes the 93 limitation.

But all in all this is the nice thing about forums allowing us to have these conversation.

Agreed

I think we need to be careful also when referring to dyno numbers.
I can make a stock Scat Pack show 1000whp if I wanted to (but won't).
What really matters is what the car ET/MPH's at the track. No lying there.
Over the years I have lined up with many cars claiming to make 1000+whp and in my much lower WHP cars (based on our dyno) walked them badly.
I personally think it is foolish to even take a stock Hellcat to the track and not throw in $15 of race fuel just to be safe.
Over the last 9-10 years we have had many stock Hellcats on our dyno for "before hits" before we modify and tune them and you would be surprised how many, especially recently, show visible detonation in our exhaust cameras when making a pull.
Yes, the knock sensors pick up the detonation but that is after the fact.

 

[Speedy!]

My bone stock 2016 Hellcat had a TON of STKR on 93. I data logged that car to see what it was doing and couldn't believe it. After this I always put 109 in the tank as you suggested.



Very next pass with 109 splashed in, just some blips after the shifts probably from the heat shields making noise.

 

[Jack_Toepfer]

What really matters is what the car ET/MPH's at the track. No lying there.

That’s why I lowballed the HP guess, btw. You guys put in the work at the track to tune the whole car, not just make max hp.

 

[Jon-MooredPerformanceLLC]

Agreed

I think we need to be careful also when referring to dyno numbers.
I can make a stock Scat Pack show 1000whp if I wanted to (but won't).
What really matters is what the car ET/MPH's at the track. No lying there.
Over the years I have lined up with many cars claiming to make 1000+whp and in my much lower WHP cars (based on our dyno) walked them badly.
I personally think it is foolish to even take a stock Hellcat to the track and not throw in $15 of race fuel just to be safe.
Over the last 9-10 years we have had many stock Hellcats on our dyno for "before hits" before we modify and tune them and you would be surprised how many, especially recently, show visible detonation in our exhaust cameras when making a pull.
Yes, the knock sensors pick up the detonation but that is after the fact.

I 100 percent agree on Dyno numbers. That’s why I’m curious on some of your testing. Same dyno. Same car. I have and I’m sure you have some people at the track say they may more then you and you win the race. Cam specs have some to do with this as well. Peak hp and a small power range isn’t everything.

 

[covidcommander]

I can agree with that. Then say it was for safety and they didnt make a tune change so it doesn't matter but it does. I guess the point I am trying to make is yes there are a lot of factors. But also the bleeding is also pushed farther away. For the people who want more power on 93 a properly setup 426 is a great way to accomplish this and that it isn't air flow that causes the 93 limitation.

But all in all this is the nice thing about forums allowing us to have these conversation.

Be nice if dodge was more involved and had a real presence in the forums.

 

[ostmike]

My bone stock 2016 Hellcat had a TON of STKR on 93. I data logged that car to see what it was doing and couldn't believe it. After this I always put 109 in the tank as you suggested.

View attachment 158844

Very next pass with 109 splashed in, just some blips after the shifts probably from the heat shields making noise.

View attachment 158845

Thanks for sharing that Speedy! This is very common and many people do not realize it. That is why we have cameras on the exhaust on the dyno. The detonation is very obvious when it occurs.

 

[ostmike]

I 100 percent agree on Dyno numbers. That’s why I’m curious on some of your testing. Same dyno. Same car. I have and I’m sure you have some people at the track say they may more then you and you win the race. Cam specs have some to do with this as well. Peak hp and a small power range isn’t everything.

We are doing our best to make our testing as accurate as possible.
It's not that we haven't installed and tuned many common modifications on customer cars. However, we are a business and have to process the work as efficiently as possible. Almost every car we have modified over the years has had multiple mods and testing each one individually was not practical. Even on our own cars there is limited time.
Cams do make a difference. Our Demon Plus cam package has been tested individually (along with proper tuning and raised RPM shifts to take advantage of the cam) knocks a tenth off the 1/4 mile ET.
The header only change has always been a question for us which prompted the testing we are doing now. We will also be testing a hit on the dyno with the headers and race fuel (Renegade Pro120) vs. ethanol without removing the car from the dyno. No timing changes, same car, same dyno, same day. We have seen gains in the past at lower power levels with similar test but they were relatively insignificant vs the cost to make the switch (injectors, fuel system, more frequent oil changes etc.). However, in a race only, high HP application ethanol shines.