Cavalli Turbo......

[JJ@WMS]

Yeah hoping to hear something soon I find it interesting ma performance doesn't seem to have fueling issues with their upgrade. :shrug:

Nobody has fueling issues on an unloaded dyno. We were able to make 370/400 on our dyno with no problem but under real world load the fueling issues will show themselves as they have with other tuning companies that have tested at the track. Even Livernois has stated fueling is an issue at higher boost/power levels.

The statements that fueling isnt an issue "even with E85" have yet to be proven. If and when its proven otherwise I will gladly eat my words but until then I will stand by the fact that proof and data mean more to me then unsubstantiated statements.

If our car laid down tons of power on E85 with no fueling issues you bet your butt we would be at the track with it to show what it could do.

JJ

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[STREETMASTERS]

It's a new platform. Takes time...and when and if the code for more power is cracked it will be a good day for all....I'd say come summer we should see some interesting things happen...

 

[BGolden]

There are only a few of these turbos right now. The one for my car will be here soon. Give the people involved a bit and you will be happy.

 

[greg hazlett]

Maybe they're throwing in some race fuel? Lol

I see what you did there...;)

 

[Impulsed7]

Race fuel would take more flow to make more power, as it has less explosive energy per amount. You would probably run out of fuel faster in that case.

Any ETA on this turbo? I have a few people bugging me about trying it. I would love to go with a pt 6262 or so, but I'm trying to keep this JLT intake.

 

[MAPerformance]

Race fuel would take more flow to make more power, as it has less explosive energy per amount. You would probably run out of fuel faster in that case.

Any ETA on this turbo? I have a few people bugging me about trying it. I would love to go with a pt 6262 or so, but I'm trying to keep this JLT intake.

Correct, the commanded EQ went up significantly once we started using the RaceGas additive @405hp. There is lot's of fuel left in the tune itself, here is an example of the car running out of fuel @5000rpms, and me making the necessary adjustments to gain more fuel. You can see I overshot it a little bit as my target AFR was 11.7 at this time, just shows what you can achieve within the tune itself.

Many of you have seen the video I posted of our 5858 turbo kit on the street (if not I will post it below), here is a log from the end of that video where I was racing the GT. I cut out 2nd gear in this pull because it cluttered the graph and it was very short with tire spin included. So the graph below is 3rd and 4th, 2 people in the car, full tank of gas, and even MORE boost with a target AFR of 11.9.

Another thing I wanted to point out is the load comparison of street versus our dyno. The first graph below is on our dyno, and the second graph is on the street. You can see they are both producing ~2.7 load at 5500rpms, so the tables we are hitting on the dyno are the same tables we are hitting on the street. Boost is the same, fuel command is the same, VE is the same, STFT is the same, and the results are the same. POWER!

One trend I have noticed is that most of the people that have posted about fuel issues are running hardware other than Cobb. I think I'm going to reach out to SCT and see if they are willing to send over their software so I can tinker around with it to see if I can produce the same results as I outlined above.

The car has been everyday on the street since last Monday, with tons of abuse and it still hasn't given us a single issue.

And, for the video:

[ame]

 

[BGolden]

Race fuel would take more flow to make more power, as it has less explosive energy per amount. You would probably run out of fuel faster in that case.

Any ETA on this turbo? I have a few people bugging me about trying it. I would love to go with a pt 6262 or so, but I'm trying to keep this JLT intake.

We will have our turbo next week according to Cavalli/Comp. Apparently the run of Subaru turbos slowed ours down. As for a release I cannot comment, but as soon as I find out I will let you guys know. I can tell you that the Cavalli/Comp turbo spools up very close in RPMs to stock and does not have the lag you may see not using the factory exhaust housing.

 

[LStillman]

We will have our turbo next week according to Cavalli/Comp. Apparently the run of Subaru turbos slowed ours down. As for a release I cannot comment, but as soon as I find out I will let you guys know. I can tell you that the Cavalli/Comp turbo spools up very close in RPMs to stock and does not have the lag you may see not using the factory exhaust housing.

I'm still curious to see if they are going to stick with the reverse rotation setup or switch to standard rotation turbo.

 

[BGolden]

it will stay reverse rotation.

 

[ScottyP3821]

Im interested in how this will stack up to the ATP turbos

 

[RubyRacer]

Any new bits of info? Did you guys at RIP get your turbo yet?

 

[96Mustang460cid]

I normally don't chime into these kinds of conversations, but I agree with you.

18psi is not the same.

18psi on our GT22s (or whatever they are) would be VERY different from 18psi on a 35R or anything else. For a better understanding you need to look at compressor maps and understand what they are showing.

Or to get simpler... think of it this way...

18psi of water spraying from a garden hose versus 18psi coming from a fire hose; what one is putting more water on the ground?

I just happenstanced across this thread and read the entire thing. I quoted smdandb2 to reference the topic of this post am using a corrected example of his garden hose analogy. It's been a while since I took these college courses and I'm working from memory. Move ahead to the next post if you dislike long-winded explanations .

With the only change being the turbo, for all intensive purposes, 18 psi from a small turbo flows the same amount of air into an engine as 18 psi from a larger turbo at the same 18 psi. I am assuming both turbos are reasonably sized for the application, not in compressor surge, similar efficiency ranges, etc.

Imagine a nozzle at the end of a garden hose that's connected to a near-by water faucet on the side of the house. For this example, the hose is flowing 2 gallons of water per minute (2 gpm). Let's say that nozzle has 45 psig of restriction when flowing 2 gpm. Now, take that same hose and hook it up to a fire hydrant. Slowly open the hydrant up and watch the nozzle restriction until is matches the previously recorded 45 psi. You will reach 45 psi at exactly 2 gpm...just like when the hose was connected to the house. Regardless of potential flow rates, a given flow rate equals a given restriction within the same "system" -- 2 gpm equals 45 psi -- with the only change being the supply source. That supply source can be a house vs fire hydrant, small fuel pump vs large fuel pump, or small turbo vs large turbo.

So, how does the above example compare to a small/large turbo example? Obviously, the larger turbo can flow more air...just like the fire hydrant can flow more water. In the nozzle example, just like a turbocharged engine, you flow whatever is necessary until you reach a predetermined pressure (measure of restriction). On a turbocharged engine, once you reach a predetermined pressure, any excess air a turbo can flow is bypassed through the wastegate. So, even though the large turbo is technically flowing more air, it's bypassing any excess air through the wastegate...and not actually pushing it through the engine. So.....all this typing is to say that two reasonably sized turbos -- one large and one small -- will flow the same air into the engine to achieve the same boost pressure.


I believe this is a theory vs reality conversation. Does the theory make a large enough difference to actually differentiate it from the SWAGs?

For the nerdy types, here's what I'm intentionally ignoring:
-- Temperature and density affects viscosity. Viscosity effects restriction of a fluid moving through a "system" (engine, in this case)
-- Turbine pressure vs manifold pressure (assuming wastegate is controlled with springs and it sees pressures on the turbine and intake side). Changing turbine pressure on a spring actuated wastegate will affect what psi the wastegate starts to open.

Disclaimer: Again, I'm working off of memory. These aren't topics I delve into too often. Please add, subtract, and/or clarify if you disagree.

Have a good day!
Michael

 

[JerseyDevil]

What your "ignoring" is your answer... Boost is a measure of restriction, you can get restriction on the 4 aspects of the turbo and the engine (intake/inducer>exducer/charge system/engine>turbine inducer>exducer/exhaust system) improving any restriction in the entire system can potentially improve system efficiency and lower boost pressure at the same airflow levels...

I just happenstances across this thread and read the entire thing. I quoted smdandb2 to reference the topic of this post am using a corrected example of his garden hose analogy. It's been a while since I took these college courses and I'm working from memory. Move ahead to the next post if you dislike long-winded explanations .

With the only change being the turbo, for all intensive purposes, 18 psi from a small turbo flows the same amount of air into an engine as 18 psi from a larger turbo at the same 18 psi. I am assuming both turbos are reasonably sized for the application, not in compressor surge, similar efficiency ranges, etc.

Imagine a nozzle at the end of a garden hose that's connected to a near-by water faucet on the side of the house. For this example, the hose is flowing 2 gallons of water per minute (2 gpm). Let's say that nozzle has 45 psig of restriction when flowing 2 gpm. Now, take that same hose and hook it up to a fire hydrant. Slowly open the hydrant up and watch the nozzle restriction until is matches the previously recorded 45 psi. You will reach 45 psi at exactly 2 gpm...just like when the hose was connected to the house. Regardless of potential flow rates, a given flow rate equals a given restriction within the same "system" -- 2 gpm equals 45 psi -- with the only change being the supply source. That supply source can be a house vs fire hydrant, small fuel pump vs large fuel pump, or small turbo vs large turbo.

So, how does the above example compare to a small/large turbo example? Obviously, the larger turbo can flow more air...just like the fire hydrant can flow more water. In the nozzle example, just like a turbocharged engine, you flow whatever is necessary until you reach a predetermined pressure (measure of restriction). On a turbocharged engine, once you reach a predetermined pressure, any excess air a turbo can flow is bypassed through the wastegate. So, even though the large turbo is technically flowing more air, it's bypassing any excess air through the wastegate...and not actually pushing it through the engine. So.....all this typing is to say that two reasonably sized turbos -- one large and one small -- will flow the same air into the engine to achieve the same boost pressure.


I believe this is a theory vs reality conversation. Does the theory make a large enough difference to actually differentiate it from the SWAGs?

For the nerdy types, here's what I'm intentionally ignoring:
-- Temperature and density affects viscosity. Viscosity effects restriction of a fluid moving through a "system" (engine, in this case)
-- Turbine pressure vs manifold pressure (assuming wastegate is controlled with springs and it sees pressures on the turbine and intake side). Changing turbine pressure on a spring actuated wastegate will affect what psi the wastegate starts to open.

Disclaimer: Again, I'm working off of memory. These aren't topics I delve into too often. Please add, subtract, and/or clarify if you disagree.

Have a good day!
Michael

 

[96Mustang460cid]

What your "ignoring" is your answer... Boost is a measure of restriction, you can get restriction on the 4 aspects of the turbo and the engine (intake/inducer>exducer/charge system/engine>turbine inducer>exducer/exhaust system) improving any restriction in the entire system can potentially improve system efficiency and lower boost pressure at the same airflow levels...

For the nerdy types, here's what I'm intentionally ignoring:
-- Temperature and density affects viscosity. Viscosity effects restriction of a fluid moving through a "system" (engine, in this case)
-- Turbine pressure vs manifold pressure (assuming wastegate is controlled with springs and it sees pressures on the turbine and intake side). Changing turbine pressure on a spring actuated wastegate will affect what psi the wastegate starts to open.

I admit to ignoring it. So, for this conversation, do you feel the larger turbo affects all of this enough to make a measurable difference?

I'm assuming the the only change is the turbo. As such, the tubing, intercooler, engine, wastegate, etc remain unchanged should not have any measurable difference in restriction.

-- Do the compressor sides of the each turbo have a large enough difference in restriction to quantify? My thoughts: I highly doubt it, but I've never measured it. Even if it did, it might or might not affect the boost output. It'd depend on where the signal to the WG was sourced and where the boost gauge is measuring.

-- Do the turbine sides of the each turbo have a large enough difference in restriction to quantify? My thoughts: It certainly could...depending on the specifics of each turbo -- turbine A/R, etc. Nevertheless, I also don't think a larger turbo, by default, has less restriction. It'd have to be case-by-case dependent. It all depends on the exact specs of the 'small' and 'large' turbos. I can see a power increase due to better cylinder evacuation. At the end of the day, I don't see how this, in and of itself, allows the larger turbo to create more boost with the same WG setting. That will be determined by the next bullet point.

-- Wastegate design: This, IMHO, has the highest likelihood of affecting the overall outcome, but we're assuming the WG remains unchanged. IF it did change, here's the three types of wastegates and controllers I'd considering:

1) Internal WG that's controlled with mechanical springs:

I think that reduced turbine pressure is unlikely to greatly affect boost output.

2) External WG that's controlled with mechanical springs

I think this scenario, by far, is the most likely to change the boost output of the turbo. A change in turbine pressure will definately affect the opening point and, subsequently, boost level on an external wastegate that's controlled with mechanical springs.

3) Internal or external WG that's controlled with boost control solenoids (BCS)

I think this scenario is very unlikely to affect the boost output of the turbo.

Remember that I'm assuming the only change is the turbocharger -- unbolt small turbo and bolt on larger turbo. As such, the WG setup and settings remains untouched.

I appreciate you entertaining the thought excercise .

Have a good day!
Michael

 

[Herr_Poopschitz]

With the only change being the turbo, for all intensive purposes, 18 psi from a small turbo flows the same amount of air into an engine as 18 psi from a larger turbo at the same 18 psi. I am assuming both turbos are reasonably sized for the application, not in compressor surge, similar efficiency ranges, etc.

If you assume both turbos are too much alike, then yes, you've built a strawman and your contentions are correct. The garden and fire hose analogy is specifically for pointing out this kind of discrepancy.

On a turbocharged engine, once you reach a predetermined pressure, any excess air a turbo can flow is bypassed through the wastegate. So, even though the large turbo is technically flowing more air, it's bypassing any excess air through the wastegate...and not actually pushing it through the engine.

Hmm...just to be clear, the wastegate is controlling turbine speed and has nothing to do directly w/ 'bypassing excess air' as you keep stating. Again, mass flow will be higher from the larger compressor than the smaller at identical output pressures.

So.....all this typing is to say that two reasonably sized turbos -- one large and one small -- will flow the same air into the engine to achieve the same boost pressure.

Take two compressor maps for similar, but one larger than the other, turbos. At identical pressure ratios the mass flow can vary substantially while staying in the same efficiency island. Or, more realistically...pushing the stock EB turbo to higher mass flow forces it outside of any good islands, so it just superheats the air. A larger turbo allows the same pressure ratio, yet can supply the required airflow while maintaining high efficiency.

Hope this helps. I'm finding this a difficult subject to talk about concisely while keeping it simple.

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