Bigger blower = more power?

[Catmonkey]

So, conclusions on as like for like comparison as I can think of? Larger blower at same boost does = more power. The curve was smoother and it is clearly running more efficiently. Not by much though. Honestly not by enough to matter with current set up. That said, the potential with the larger blower with larger CAI + TB + E85 is FAR greater than it is with smaller. Nevertheless, the data is what it is and larger blower was +20 WHP.

Here's Eaton's own analysis of the difference between the TVS 2.3 and the 2.65.

R2650 versus R2300

• 4% more efficient
• 15% larger (2300cc vs. 2650 cc)
• 18% less input power required
• 25% more air flow at 18,000 RPM and 14 psi boost (2.0 Pressure Ratio)
• 72% isentropic efficiency vs. 68%

Eaton also makes it's supercharger maps available. Assuming both superchargers are turning 6,000 rpm at 17 psi, the 2.65 would be operating in an isentropic efficiency of 66%, while the 2.3 was 11% less at 55%. There's no doubt in my mind that the 2.3 is starting at run out of steam on our engine peaks for the 5.4 and moreso on the 5.8. It gets worse when we change our fuel source to E85. I also don't believe the 2.65 falls into the category of too big.

I would like to see how the Gen 3 would compare to a 3.5 to 4 liter blower using pump gas. I think that comparison would change the bigger is better dynamic, but again I think the answer is it depends on what blowers are in the analysis. I'm sure the bigger blower would come out on top if we changed the fuel source to E85 where the engine can tolerate a lot more boost.

What I really like to know is how your torque peaks compared between the 2.3 and 2.65?

 

[Klaus]

For your engine size and the blowers used, pretty much what you would expect.

Not quite. Expectation was ~700 with twin 67. Here is VMP video where Justin dynos a 2012 part by part and hit >700whp on 2.8 pulley with stock manifold and 56# injectors but with his vaporware mono 160. With 2.6 he hits 721whp. I have bigger injectors and headers and should have been >700 although my tuner erred on side of conservatism.

What I really like to know is how your torque peaks compared between the 2.3 and 2.65?

I will take a picture of the graph. They are right on top of each other though. gen 3 lags very slightly up to 2500 rpm, gen 2 lags very slightly beyond. Curve on gen 3 is smoother. It is really tomato/tomatoe at this level as fuel is by far the biggest limiter.

 

[Catmonkey]

That's good to know that torque is about the same. I should have mine mounted this weekend. Any tips/surprises on the manifold cutting? How big a PITA was the EGR tube? Any pointers on that one?

 

[Klaus]

That's good to know that torque is about the same. I should have mine mounted this weekend. Any tips/surprises on the manifold cutting? How big a PITA was the EGR tube? Any pointers on that one?

I will ping tuner on EGR. I think the manifold cutting was pretty straightforward. There is a video on VMP site with this if you did not see. What TB are you running?

 

[Catmonkey]

I will ping tuner on EGR. I think the manifold cutting was pretty straightforward. There is a video on VMP site with this if you did not see. What TB are you running?

Okay, so you didn't do the install. I will run the 67mm on the street. Waiting to see if VMP gets it's act together on their TBs. I have to think they will find an alternative for their one-off TB bolt pattern.

I posted the video on one of these threads. It's one thing if it's you've done several already, but it's a bit intimidating to take a cutting tool to your intake manifold. I'm sure it will be fine. I'm more worried about that EGR tube.

 

[merkyworks]

I agree Klaus's compare is as like for like as one could get and a good example. Also this is a great discussion.

But Klaus's comparison of a 2.3L TVS to a 2.65L TVS made me realize in all of our discussions/examples we are comparing SC size but never do we account for roots SC to twin screw SC. Isn't the boost/air flow characteristics of roots Vs twin screw different enough that it should be a factor as well?

 

[sono]

With years of blower debate the raw data is still elusive!
WHY?

Run a 4.0 whipple vs 3.6 kb vs 2.65 tvs ect. on the same car.
The one with best curve answers our questions.

The only other variable is heat decay.

 

[Weather Man]

Not quite. Expectation was ~700 with twin 67. Here is VMP video where Justin dynos a 2012 part by part and hit >700whp on 2.8 pulley with stock manifold and 56# injectors but with his vaporware mono 160. With 2.6 he hits 721whp. I have bigger injectors and headers and should have been >700 although my tuner erred on side of conservatism.

With what Danny is trying to accomplish and what VMP is trying to accomplish, I stick with my statement.

 

[Klaus]

See @19COBRA93 discussion of his build in the VMP throttle body thread if you are wondering what this blower can do. Same set up as mine, w/ larger TB and 149 CAI. 778 WHP @ 17 lbs of boost. Gen 3 is a monster.

 

[69b302]

That’s the side of the argument I’m not agreeing with. 15psi from one blower is not equal to 15psi from every blower as far as volume because that would leave your HP gains only to thermodynamics and efficiency characteristics of each blower.

Yep, thermodynamics and efficiency characteristics are the main factors. What other factor are you thinking it could be? Does one blower add something to the air that another does not(other than heat)?

 

[StrayBullitt]

R2650 versus R2300

• 4% more efficient
• 18% less input power required

Ok, so Are we then chalking @Klaus gains on the dyno (with less timing / more heat) up to only less parasitic losses on the Engine ?

 

[GT Premi]

... Does one blower add something to the air that another does not(other than heat)?

Only turbos have that magical power.

 

[Catmonkey]

Ok, so Are we then chalking @Klaus gains on the dyno (with less timing / more heat) up to only less parasitic losses on the Engine ?

I don't know about we, but that's my conclusion. Blower rpm is down 14.3% over his prior configuration. If you believe Kenne Belle's propaganda, it takes a 2.3 TVS 147 horsepower to make 14.5 psi of boost. That's 26 horsepower if you take Eaton's word at their 18% less power input. Surely it takes more horsepower to get to 17 psi. Heat is not really a consideration as much as timing, although they are somewhat related. Higher IAT2 can cause detonation and reducing timing is an attempt to remedy that. Other than that heat is not really a factor. What I find interesting is given both configurations, the Gen 3 is theoretically pumping 528 liters per minute less than his 2.3 at redline. I'd love to see a boost graph of both pulls to see how that compares.

 

[RedVenom48]

I suppose one question I have through all this is what kind of restriction IS a standard bolt pattern Mono TB compared to the VMP exclusives?

You can see the difference here of where the TB bolts go for the new Gen 3 case and the traditional GT500 pattern.

Consider that even the 4.0L Whipple's use the standard GT500 TB pattern, I have to imagine its not a bottleneck.

@Klaus I lol'ed at the vaporware comment. I stand by my statement that the Gen 3 should have used the standard both pattern and an R version with the "new pattern". Would have made rollout A LOT simpler.

 

[Catmonkey]

I suppose one question I have through all this is what kind of restriction IS a standard bolt pattern Mono TB compared to the VMP exclusives?

Other than it's slightly smaller and probably doesn't flow as much as the larger mono, using the adapter plate shouldn't result in a restriction. There's probably enough material to drill additional mounting holes on a standard throttle body if you didn't want to use the adapter plate.