Talk me into a centrifugal

[80FoxCoupe]

talking about the torque booster adding more power compared to without

This graph for example...like 10hp at 4k but like 70 at 5k. Nice boost but it doesn't really fatten the low end up like OP wants

You are talking about tq booster vs without, I misread.

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[Beaujangles]

Wow, you guys must have been reading my mind, as I am getting ready to do the ESS G3 thing to my Bullitt and was going to ask for opinions/advice before I drop the dime on it...

 

[blakeman8192]

Post a log that shows iat that is 5-6deg obove ambient on a full pass.

Yeah I may have been wrong with that one because my car is really just a street menace and I don't spend any time on the track/strip. But after long a long pull from 30-130 I can look down at my gauge cluster and still see temps still only a bit above ambient. It's mostly CHTs that rise on hotter days for me.

 

[Gregory347]

Yeah I may have been wrong with that one because my car is really just a street menace and I don't spend any time on the track/strip. But after long a long pull from 30-130 I can look down at my gauge cluster and still see temps still only a bit above ambient. It's mostly CHTs that rise on hotter days for me.

according to your sig you are running meth… that’s chemical cooling and perhaps why your IATs are where they are… 30-130 would make IAT climb

 

[blakeman8192]

according to your sig you are running meth… that’s chemical cooling and perhaps why your IATs are where they are… 30-130 would make IAT climb

Yeah but I haven't done IAT sensor relocation yet, meth is injected after the temps are measured still.

 

[NightmareMoon]

I'll try to talk you out of it, for your particular case.

Centrifugals like gear. They like the 10 speed auto. But, they aren't as 'weak' at say, 5,000 RPM as some people might believe.

The last thing you want to do take gear away on a stick centrifugal car. At least you could put a torque converter in an automatic and fix the low RPM issues.

I'd put money on the base turbo kit from whoever making power 1,000 rpm earlier than any centri. You can try to use those 'torque booster' setups but you honestly aren't going to spin the thing fast enough to make a large amount of power down low, and if you did, it'd be so out of the efficiency range on the high end...

If you look at the dynos they don't really add anything noticeable up until 5,000+ anyway.

Good man

Yeah I see that they dont have lag, they’re just weaker at low RPM. Im my case (autocross), I’ll be in 2nd gear at whatever RPM the course allows, and if I’m getting on the power its probably digging out of a 35mph corner to accelerate up to 70mph before hitting the brakes for the next slow element. I need more than NA torque to pull out of corners at low RPM and to makeup for the torque hit I’m going to take from switching to 3.31 gears

It looks like Centris sort of do that. I’d have a little more power at 3k than stock but not tons more and sure once I get going things will build ok. With a turbo, by the time it spooled I’d be out of time and hitting the brakes. Its very hard to prespool for a corner exit with your foot, so turbos are out, but I’m on the fence about Centris

A wipple might be the right choice for power delivery (more boost at low RPM??) but they’re heavier and more expenaive.

 

[ShadesOfBloo]

Talk me into a centrifugal

I will not.

Car is 40% street, 50% autocross, and 10% track.

I have to rebuild (or part out) this Gen2 motor, so I need to decide on boost and choose a 9.5:1 compression motor or a 12:1 NA optimized motor.

I've had great results with this as an NA build, but I want more power/torque, and for reasons I want to lower the diff ratio to get a higher top speed in 2nd gear, which implies going from 3.73s to 3.31s and therefore losing torque in the process.

I had a smaller 1.8l turbo sports car in the past and loved the turbocharger's personality, but it looks like the spool time for these V8s from a lower RPM is too long for my autocross habits. Plus the weight of system. This car turns corners so weight is the enemy. I wish there was a turbo kit optimized for hyper fast spooling at the expense of top end power. ~600-650 at the wheels is my goal, I don't need 800 to race around parking lots with cones.. even big parking lots.

So I'm considering the ESS or P1X.

We have an engine that needs RPM to be responsive and make good power.
(Well, maybe my 2020 more so than your 2016, but you're building a motor so maybe I shouldn't speculate too much.)
A centrifugal supercharger also needs high RPM to work well. They complement an engine if it made torque down low and ran out of steam well before redline, so, pushrod motors and maybe SOHC Modular engines.
The track is where the centrifugal blower would probably work best for you.

If we look at who's kicking ass at autocross, aren't there a lot of screw-type blowers in the CAM classes?

Yeah I see that they don't have lag, they’re just weaker at low RPM. Im my case (autocross), I’ll be in 2nd gear at whatever RPM the course allows, and if I’m getting on the power its probably digging out of a 35mph corner to accelerate up to 70mph before hitting the brakes for the next slow element.

I was going to propose that you match your build's redline and gears to go at least 70mph in 2nd gear. 7500rpm and a 3.31 rear end should do it, with your MT82 ratios.

I need more than NA torque to pull out of corners at low RPM and to makeup for the torque hit I’m going to take from switching to 3.31 gears.

It looks like centris sort of do that. I’d have a little more power at 3k than stock but not tons more, and sure once I get going things will build ok. With a turbo, by the time it spooled I’d be out of time and hitting the brakes. Its very hard to prespool for a corner exit with your foot, so turbos are out, but I’m on the fence about centris

A Whipple might be the right choice for power delivery (more boost at low RPM??) but they’re heavier and more expensive.

Also, I remember the twin-turbo kits being more expensive than the superchargers.

I've read elsewhere on this forum that cam timing is important to boost. I've read that some tuner that really knew his stuff started tuning someone's supercharged car with the default tune, and with cam timing he made boost go down, and cylinder head temps go down, and power went up.
Remember "boost pressure" isn't really a measure of flow, but how hard the flow is pushing back, i.e. resistance. I can see where the right cam timing reduces resistance, and increases flow.

And, most types of supercharger have boost controllers of some kind.
Some people are using "boost-by-gear" software in their cars, including on this thread:
https://www.mustang6g.com/forums/threads/boost-by-gear-with-oem-logic.196272/

...And Jonathan Blevins' 2008 car that kicked ass at the Optima Ultimate Street Car Invitational.
I think I might have heard him mention the VMP boost-by-gear feature in an interview rather than in writing.

 

[HKusp]

I'll mention this, instead of a Centri, do an NA Godzilla swap and LOVE all that torque and HP without ANY lag at all....

https://media.giphy.com/media/v1.Y2...WZfYnlfaWQmY3Q9Zw/l4FGl5oHLL4vqOvV6/giphy.gif

 

[NightmareMoon]

I'll mention this, instead of a Centri, do an NA Godzilla swap and LOVE all that torque and HP without ANY lag at all....

https://media.giphy.com/media/v1.Y2...WZfYnlfaWQmY3Q9Zw/l4FGl5oHLL4vqOvV6/giphy.gif

$26,500 for a Aluminator XS 5.2. Looks god tier though.

 

[NightmareMoon]

If we look at who's kicking ass at autocross, aren't there a lot of screw-type blowers in the CAM classes?

I was going to propose that you match your build's redline and gears to go at least 70mph in 2nd gear. 7500rpm and a 3.31 rear end should do it, with your MT82 ratios.

I've read elsewhere on this forum that cam timing is important to boost. I've read that some tuner that really knew his stuff started tuning someone's supercharged car with the default tune, and with cam timing he made boost go down, and cylinder head temps go down, and power went up.
Remember "boost pressure" isn't really a measure of flow, but how hard the flow is pushing back, i.e. resistance. I can see where the right cam timing reduces resistance, and increases flow.

And, most types of supercharger have boost controllers of some kind.
Some people are using "boost-by-gear" software in their cars, including on this thread:
https://www.mustang6g.com/forums/threads/boost-by-gear-with-oem-logic.196272/

...And Jonathan Blevins' 2008 car that kicked ass at the Optima Ultimate Street Car Invitational.
I think I might have heard him mention the VMP boost-by-gear feature in an interview rather than in writing.

Hey, I can safely say that very few people kick my ass at autocross. I beat Shotz's ZL1 1LE (whipple) Optima car in 2022 at Nationals and took the W right out from under him.

Last year I did loose to Shotz's fully built SS 1LE, Otis's ZL1 1LE (who is local to me and usually spanks everyone - he's an alien), and a 4-banger Camaro. I was sore about losing to the 4 cylinder.

So, that doesn't tell us much about what's the winningest combination (turbo 4, NA V8, Wipple V8), but I run against Otis a lot and I do feel like his power AND 2nd gear top speed limits are impactful. Shotz thought his ZL1 was front top heavy with the blower which is I think why he said he built the NA SS car for '23.

I figured the Centri might be a win if I can keep at least my currently level of low RPM torque (after dropping down to 3.31) - the car wouldn't be any slower at low RPM, and it would be faster at high RPM and could run to 70. We're often in a low RPM out of low speed tight corners, but you can't really romp on it until you get the car straightened out some, which leaves some time for the RPM/boost to build. My general strategy is to optimize for the fast sections (but those are going to often be ending in some sort of maneuvering through offsets or slaloms at nearly 65mph, so front-top whipple weight may indeed be an issue.

 

[josephstef]

I had an ESS G3 on my 2016, pulled it off and put a TVS2650. Was the best decision I ever made.
My car is just for street, I hated the fact that I had to get the RPM range high to have fun.
Now I can get up and go any rpm and get pinned into the back of my seat. So much better... for me anyway

 

[ShadesOfBloo]

Hey, I can safely say that very few people kick my ass at autocross. I beat Schotz's ZL1 1LE (whipple) Optima car in 2022 at Nationals and took the W right out from under him.

So, why are you asking us forum scrubs for advice?!?

 

[NightmareMoon]

So, why are you asking us forum scrubs for advice?!?

Cause I cant make a decision and I’ve never owned a car with a centri. Plus I value your opinion on what to do with my money on my own car which only I will drive

 

[tdstuart]

If you want low end power I would be looking at a PD blower or turbos. You realize you can just run smaller turbos right? They might not be included in the kit but if you run a smaller turbo it will spool faster and take away your top end. You can optimize other things about turbos to get them to spool faster too.

I would do more research on turbos before ruling them out.

 

[80FoxCoupe]

Cause I cant make a decision and I’ve never owned a car with a centri. Plus I value your opinion on what to do with my money on my own car which only I will drive

Centri will be everything you love about the character of the coyote engine, but more. True story.

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