Not necessarily smaller in terms of duration or lift, but more optimized valve events.

Maybe something like this:

https://cammotion.com/camshafts/cs-2...r-centrifugal/

 

Changing valve events would change duration and centerlines....also whatever it does on motor you can expect it to do on boost...

 

Check this guy's thread (post 397 gives the bottom line). He thought the same, that his cam was holding him back during an F1A-94 to F1X swap. Changed the cam from a Jam Cam to an "optimized" cam by a reputable cam guru and only picked up 20HP. Now this was case of not enough motor and too much blower, where you would expect more cam would help it breathe better but it wasn't a big pickup,

https://www.corvetteforum.com/forums...v2-5-a-20.html

 

Just because the math works out doesn't mean the combo is working, because the math WILL ALWAYS work out. Adding 7-8 psi on just about any motor will produce around 50% more horsepower, but that doesn't mean the combo is optimized for it nor does it mean that the power/psi is where it should be. My combo once had a bypass valve that stayed open and the car made 6 psi instead of the 12 psi it was supposed to. Power was down, but the math was still correct which doesn't mean a damn thing.

There could be multiple issues hurting the performance. Potential culprits are cam, intercooler, bypass valve, boost leak, belt slip, throttle not opening up all the way, bad fuel, etc. A cheap or undersized intercooler can quietly restrict flow and keep the power down. No matter how much blower rpm is pushed the power will not change.

You're right that boost is just a measure of restriction and irrelevant. Power is the issue here and it is way down from where it should be. Even at 58k rpm that combo should be making at least 100hp more than it is and the psi measurements are horribly low. The OP didn't post the hp from the 3psi turboguard run, but that is the realistic setup to run on the street. I'm guessing it landed somewhere in the 650 range which is f-d up. Also OP, was the 500 hp engine dyno run with any kind of filter?

All this talk about the motor being too big is bull crap. Put a 1000 hp blower on a 400 hp motor and it can make 1000 hp. Put a 1000 hp blower on a 650 hp motor, and it will still make 1000hp. Put a 1000 hp blower on a 900hp motor and it will make 1000 hp. Put a 1000 hp blower on a 1200 hp motor and it will only make 1000 hp.

With a good blower cam, intercooler and a maxed out blower that combo should be in the 900s with a turbo guard.

 

you can keep the same duration and change the LSA and or advance the cam for example which could certainly change the ICL or you could keep the duration on both intake and exhaust as well as the ICL and only move the exhaust lobe which would change the LSA.

 

What makes you think his valve timing events aren't optimized or that this cam is somehow more optimized?

 

It's funny you say that because I originally experimented on my setup with 3 smaller BOVs and tried "wastegating" it to kill off some torque down low and while it worked it definitely was way less efficient, and the math didn't work anymore either at that point as it was seriously under par with boost vs power.

I don't see any evidence of any of that, but I also don't see a dyno graph or anything either.

What evidence do you have to suggest any of this? Do you know anything about the dyno it was run on or any of the run conditions? Maybe it's an eddy current dyno? The only thing to go off of is what it made N/A vs what it's making now and it seems normal to me and different dynos read differently. There are plenty of dynos out there that wouldn't show a big number compared to a standard dynojet dyno.

Not sure why anybody would say the engine is too big, it's irrelevant.

 

Well today we learned that engine combos and cams don't matter with prochargers...

How do we explain a car with a smaller engine making more power with the same blower and a 4.5" blower pulley not spinning the blower much different speed than the OP yet making more power...

Something matters...


Coyotes have made 1000 rwhp spinning the blower to max impeller speed. Since motor combos and cams don't matter why do these little fords make more power with the same blower cfm?

ETA: honest question I would like to see this explained to learn from it.

 

Hey we've got another thread going where we were told that cams dont matter either with boost and guys like Billy Godbold are just sales men. 🤷 I guess all classes races limited in boost and c.i. all use the best NA cam.

 

No one said cams don't matter. Putting a smaller cam in it will pull the powerband down. Cause you know, that's how it works. You guys are trying to sell the OP on a cam swap when his combo is doing exactly as it should and if he wants more power he just needs to add boost. And comparing two completely different platforms with 2 completely different dynos is irrelevant. Too many variables to consider. Ya there might be a little optimization that could be done, but i mean really? Find me a group of cam gurus that will agree on what the "optimized" cam is. You won't. It's not worth the time money and effort.

 

No one said he needed a smaller cam. He could change the LSA and advance and possibly keep the same NA power and pick up boost and power without changing anything else.

Earlier in the thread a comparison was made between a well proven centri cam the jam cam to another custom cam and said it only picked up 20 hp with no other changes. Twenty hp is twenty hp especially when doing it without adding any boost especially considering the jam cam is an already good proven performer with a centri.

Here is a different story because he's got an NA cam and switching to a custom centri cam he might pick up 50 hp. Fifty hp is nothing to sneeze at when we are talking about doing it without spinning the blower any harder. Then spin the blower faster like we all agree on and pick up another 100 easily. At that point he's up 150+ and closer to where I'd expect that blower to be.

The mustang comparison is perfect...we are literally being told the cam is going to make little to no difference don't bother even though it's a super simple/cheap mod on our platform and that cubic inches, heads, etc don't matter the blower is going to make the power. The mustang is around 100 cubic inches less with stock cams/heads and is making more than the OP with a bigger pulley on the blower than the op. 4.5 to 3.85 pulley on the op's combo. I made more with the D1x on my 377 with a custom cam motion cam and stock ls1 heads with a spring kit when I had a 3.85 pulley on the head unit. Later I went to a 3.55 and picked up good power, but it wasn't like it was a game changer so I went to the f1a-94.

I think it shows the engine combo does matter. It matters less with boost than NA we all agree upon that, but to say the cam and engine combo makes no difference worth the time I would disagree with in this case.

I get it dyno's vary, but there is no shortage of coyote mustangs running the ET and MPH to demonstrate the really are making the power with little p1x and d1x blowers. The blower is going to make the power no matter what motor it's on is what we are being told then why are smaller motors with stock cams making way more with the same blower over and over not just an isolated case?

Honest question I'd like to see answered rather than just it's a different platform. Yes it's a different platform so we are saying the engine combo does matter or not? As the same blower being used on coyotes are making 1000 rwhp when pushed while you don't see a d1x making 1000 rwhp on an LS ever.

 

I must have missed it on the S550 video, what was the crank pulley diameter and Peak rpm on that pull?

 

Who said that? It's all about powerband and it's intended use and you cam it accordingly.

Huh? You are comparing an entirely different type of motor, one that is much more efficient and revs to the moon. As an example we made 875 rwhp on a Gen3 Coyote with a puny P1X and we could have spun it harder.

 

The Mustang comparison is stupid, it's an entirely different engine that is way more efficient and revs to the moon. What they lack in torque they make up for in horsepower.

Are you done trying to make comparison between your combo and his when you know nothing about the dyno its being done on, the run conditions, etc? It's meaningless banter at this point...

 

Reply in sig....

 

7psi → 4psi: this is all over the internet, guys "picking up 100hp" by removing filter, adding a stack etc. my experience sais it doesnt happen, theory sais it should not happen (as opposed to a n/a setup, where every bit helps).

here a "turbo guard" is loosing half of the boost. im not saying it didnt happen, just wondering what the reasons might be for such behaviour. extremely restrictive wire mesh in this case?