I CANT MAKE A DECISION!!! Jrsc or edelbrock.

[CSG Mike]

Originally Posted by gtengr

OEM's use the Eaton (e.g. Audi S5 B8). How many OEM's use a centri?




I made my decision based on the number of Rotrex replacements I've read about on this forum, and the fact that the Eaton-based blowers use an OEM quality charger. I was going to get the Edelbrock kit (was waiting on the 2017+ update at the time), but a used Cosworth popped up nearby so I just went with that. Actually glad I went Cosworth now due to the number of bypass valve issues with the Edelbrock.

Koenigsegg?

[gtengr]

Originally Posted by CSG Mike

Koenigsegg?

Sure, but versus Corvette, Cadillac, Audi, Ford, Mercedes, Lotus, etc.? If I'm betting on reliability, I know where I'm putting my money.

[Kiske]

A lot of it for oem's is how nicely and compact a roots blower sits nestled down in a V configured engine too...

[mrg666]

Originally Posted by gtengr

Sure, but versus Corvette, Cadillac, Audi, Ford, Mercedes, Lotus, etc.? If I'm betting on reliability, I know where I'm putting my money.

You keep repeating this reliability thing without any data. Please show the data of number of failing Rotrex units vs the number sold.

Where you put your money is your concern. I believe I can be smarter with my money. Can you argue with that?

[86TOYO2k17]

Originally Posted by mrg666

You keep repeating this reliability thing without any data. Please show the data of number of failing Rotrex units vs the number sold.

Where you put your money is your concern. I believe I can be smarter with my money. Can you argue with that?

I would love to see some data on this. Can you provide it?

Better yet a comparison of all units sold of every supercharger for this platform, failure rate of every supercharger, average number of mileage before failure, and impact/cost to fix the failure. and then you could weigh this and factor it against the performance of the supercharger for your own individual decision.

Having this information would be the smartest way to make a decision on spending your money.

[mrg666]

Originally Posted by 86TOYO2k17

I would love to see some data on this. Can you provide it?

Better yet a comparison of all units sold of every supercharger for this platform, failure rate of every supercharger, average number of mileage before failure, and impact/cost to fix the failure. and then you could weigh this and factor it against the performance of the supercharger for your own individual decision.

Having this information would be the smartest way to make a decision on spending your money.

I am saying that there is no complete reliability data. Yet you are asking me to provide it? I didn't ask your recommendation for spending my money either.

[bfrank1972]

Too many variables here - we're all using aftermarket kits for comparison, but even the best kits are no where near OEM levels of engineering and packaging (bay location, drive, lubrication, cooling, etc.) Turn key shops like Lingenfelter, Dinan etc. are better-ish for overall package completeness but it's really tough to make an apples to apples comparison. There may be also a supply thing going on, maybe Rotrex just can't supply large scale? (just a wild guess). Would be interesting to hear from an actual automotive engineer on this topic.

[mrg666]

Originally Posted by bfrank1972

Too many variables here - we're all using aftermarket kits for comparison, but even the best kits are no where near OEM levels of engineering and packaging (bay location, drive, lubrication, cooling, etc.) Turn key shops like Lingenfelter, Dinan etc. are better-ish for overall package completeness but it's really tough to make an apples to apples comparison. There may be also a supply thing going on, maybe Rotrex just can't supply large scale? (just a wild guess). Would be interesting to hear from an actual automotive engineer on this topic.

I think we all agree that roots blowers are very reliable, mostly because of their simple design. We also agree that all PD blowers provide low-end torque that is very desirable for many drivers since power is delivered without a down-shift requirement.

There are claims that we do not commonly agree. Many claim that Rotrex is unreliable. I agree that Rotrex is probably a more delicate and complicated design than PD blowers since it can operate without gears past 100,000 rpm that require tight tolerances. But this brings the efficiency advantage of Rotrex. And, there is no complete data to support this "unreliable" claim. My experience is just opposite and there is extensive track record as well.

This "Roots is OEM choice" claim, I will just discount it as irrelevant since we are modifying an NA engine that was not designed for FI to begin with. My primary concern would be engine reliability than the reliability of supercharger. Rotrex is a safer application for our engines due to lower low-end torque. As a second priority, I would consider the supercharger reliability and Rotrex is a proven aftermarket product on many car brands. Honda had an OEM supercharger kit with Rotrex.

Since PD blower applies a constant boost from low to top rpm, it is better to have lower top rpm power for engine reliability. Since Rotrex builds the boost linearly with rpm, it gives up some power at lower rpm but can provide more power at higher rpm.

All I am saying is that the answer for that question in the first post is not as simple as calling Rotrex unreliable, Edelbrock very reliable.

[gtengr]

Originally Posted by mrg666

You keep repeating this reliability thing without any data. Please show the data of number of failing Rotrex units vs the number sold.

I never claimed to have any data, and I've explained the reason behind what was clearly defined all along as my personal opinion. You don't have this data on the Rotrex either, but I'm supposed to just take your word on it over my instincts?

Originally Posted by mrg666

There are claims that we do not commonly agree. Many claim that Rotrex is unreliable. I agree that Rotrex is probably a more delicate and complicated design than PD blowers since it can operate without gears past 100,000 rpm that require tight tolerances. But this brings the efficiency advantage of Rotrex. And, there is no complete data to support this "unreliable" claim. My experience is just opposite and there is extensive track record as well.

I never claimed Rotrex is unreliable. You're putting words in my mouth. I just think the Eaton base is more reliable. There is a difference. Interesting to see you admit the Rotrex is probably a more delicate and complicated design, and then conflate efficiency with reliability, even though efficiency was never questioned.

Originally Posted by mrg666

This "Roots is OEM choice" claim, I will just discount it as irrelevant since we are modifying an NA engine that was not designed for FI to begin with.

Really? You don't see how the R&D that goes into becoming a mass market OEM supercharger provider might bleed over into the aftermarket applications that use the same charger?

Originally Posted by mrg666

As a second priority, I would consider the supercharger reliability and Rotrex is a proven aftermarket product on many car brands. Honda had an OEM supercharger kit with Rotrex.

It's amusing, but no longer really surprising, that you'd suggest a Honda-made CR-Z aftermarket kit using a Rotrex signals more about charger reliability than an Eaton being used on mass production cars. The real kicker is that you just dismissed part of my reasoning about the Eaton as "irrelevant since we are modifying an NA engine that was not designed for FI to begin with", and then turn around and introduce a Rotrex kit for an NA engine as evidence of reliability.

[toast]

Originally Posted by mrg666

Since PD blower applies a constant boost from low to top rpm, it is better to have lower top rpm power for engine reliability. Since Rotrex builds the boost linearly with rpm, it gives up some power at lower rpm but can provide more power at higher rpm.

This is incorrect. A PD blower does not apply constant boost. If you put 10 psi into this engine at 2000 rpm it would be dead quickly. The Eaton unit builds boost linearly.

[mrg666]

Originally Posted by toast

This is incorrect. A PD blower does not apply constant boost. If you put 10 psi into this engine at 2000 rpm it would be dead quickly. The Eaton unit builds boost linearly.

I'm not sure where you got confused. Please read by yourself to figure out. Not interested in another back on forth.

[toast]

The level of condescending douchebaggery you convey borders on amazing. I have no interest in a back and forth with someone of your exceptional level of armchair engineering, but in this case it is not necessary, you are simply wrong.

The Edelbrock provides a fixed volume of air per revolution, not boost. When running WOT that volume creates a pressure in the manifold that is proportional to rpm. My boost scales linearly with engine speed; at 2k I get about 2 psi of boost, by redline it is 11 psi. I can provide logs if necessary.

[ROFL it's Waffle]

TorqAmp

[86TOYO2k17]

Originally Posted by toast

The level of condescending douchebaggery you convey borders on amazing. I have no interest in a back and forth with someone of your exceptional level of armchair engineering, but in this case it is not necessary, you are simply wrong.

The Edelbrock provides a fixed volume of air per revolution, not boost. When running WOT that volume creates a pressure in the manifold that is proportional to rpm. My boost scales linearly with engine speed; at 2k I get about 2 psi of boost, by redline it is 11 psi. I can provide logs if necessary.

My Sprintex according to my mechanical boost gauge tapped off the map plate reads about 10psi on WOT at 4k rpm and gradually goes up to about 13.5psi at redline.