Turbo VS Supercharger

[slomaro1]

I would go with a turbo because you can make a lot more power

[ZZZTOPZZZ]

Originally Posted by fif_gen_powa

lol ok so whats your best time slip lets see it

If things work out this summer, I may be able to get down to the strip in Milan, MI. Car should be in the shop toward the end of this month for the new cam and reworked heads. Then I'm off to Florida (gulf side) for a month or so after Easter.

[stevieturbo]

Originally Posted by Scuzz

I've had both. I had superchargers on my Camaro from 600rwhp to 1050rwhp. And now I have turbos at 1300+.

If your target is 600-800 go supercharger. If you want more then 800 go turbos.

Supercharger builds are much simpler then turbos. Less little odds and ends. Also if you stay at say 700rwhp you have more area under the power curve vs a turbo build at the same power. They bring the power on differently. maybe you dont like the power down low.

Pretty much this., although I could stretch the blower a bit further.

Only deviation from this, is if there are audible and visual aspects you might prefer for each setup.

The noise of my YSi did get tiresome...more so from a daily driver point of view.

Turbos are silent by comparison. And the instant throttle response of the blower is also very nice to have. Anyone who claims their turbos are instant too...are liars. Not one has ever been able to back their claim up with datalog evidence when I've challenged them.

Some are very good, and quite fast...but never SC or n/a instant.

[Moreair1]

Originally Posted by ZZZTOPZZZ

If things work out this summer, I may be able to get down to the strip in Milan, MI. Car should be in the shop toward the end of this month for the new cam and reworked heads. Then I'm off to Florida (gulf side) for a month or so after Easter.

Do you have plans for a roll bar/cage? If you run at a track and they stay strict to nhra rules the fastest you will be able to run is 13.50s, if you go full out they will probably give you one warning then the second run you would be done

[ZZZTOPZZZ]

Originally Posted by Moreair1

Do you have plans for a roll bar/cage? If you run at a track and they stay strict to nhra rules the fastest you will be able to run is 13.50s, if you go full out they will probably give you one warning then the second run you would be done

Yeah, I hear you on all of that. No roll bar or cage. However, Milan is not a sanctioned strip. Unless they change the rules this season, all they require is a helmet and seat belts. It's more or less setup for 'grudge' match runs.

[RealQuick]

Let’s clarify somethings as some info can be misconstrued.

Two types of blowers are typically used (positive displacement and centrifugal). Screw chargers are third type but will be ignored for this discussion.

Both positive displacement and centrifugal types give instant boost... but positive displacement is basically full boost once the pedal goes down and the bypass valve closes. So with a 10psi pulley... mash the gas at 3k rpm and you are instantly at 10psi.

Centrifugal supercharges compress air... and as such, the faster it spins the more boost it makes. The boost is pretty linear. Example: 10psi pulley will make 6psi@3k, 8psi @ 5k, and 10psi at 6k. These numbers are just used as an example to explain the theory behind it. We will ignore drive ratios and boost will vary on compressor size.

Turbos drive off of load (pressure differences across the turbine). Pressure and heat are tied together, but let’s keep the example simple. Turbo setups, while they have lag as mentioned, can ramp up the boost very fast. Example: you could have a 10psi wastegate spring... when you mash the gas at 2800rpm, you may only have 1psi by 3k rpm... but you could be at 10psi by 4.5k and hold 10psi all the way to 6k. Turbo spool and boost increases can be violent/fast. Hitting full boost sooner means more area under the curve and should make for s faster car if set up properly.

[RealQuick]

Just a quick example of my boost curves (2nd gear it’s on the street) twins vs single

Within 1400rpm I go from 0psi to 11.5psi with the twins.

[dreksnot]

A number of years ago I overlaid different FI power/torque delivery. Don't look at peaks; actually look at how the torque and power come on. Same dyno, same day - it was a Dyno Day!

Garth has a roots [forged LS3, heads, 16psi]
Hubbard has a centri [SBE LS3, D1, 15psi]
Ray has twins [SBE LS3, head work, 10psi]
Allen has nitrous [SBE LS3, 200 shot]

The top graph is horsepower
- as we'd expect, the centri produces more power as RPMs climb

The bottom is torque:
- as we'd all expect, roots and nitrous produce tons of bottom-end torque
- as turbos spool up, so does the torque

My believe is the more area beneath the curve (power band 4,500 to 6,500RPMs) during a race is going to win.

[hunter1660]

According to Google, only need roll cage if faster than 9.99 or 135 mph.

[mrimpala02]

Also according to Google, 30% of all car accidents are caused by drunk drivers. So 70% must be caused by people NOT drunk. Does that mean your odds of being in an accident are better if you ARE drunk?

Just giving you are hard time hunter1660 :-)

[stevieturbo]

Having seen pictures of some cages guys use...I think I'd be trusting the OEM safety cell they designed to keep the driver etc safe in a modern car.

Lets not forget, lots of the old rules are based around ancient pieces of crap with no brakes, terrible chassis, and generally dangerous cars to start with.

There are bone stock cars that exist now, that can easily exceed the traps/ET's for lots of their silly rules...and you can be sure a lot of the NHRA safety features...would in no way make those cars safer for 99% of their usage.

I'd far sooner race against a car with no cage, but sensible wheels and tyres....as opposed to a car with big wobbly tyres and skinnies up front, which mean they wont handle, and wont brake....and will go out of control very easily.
And of even more importance is the ability of the drivers...which is never checked. And there are some crazy fools out there.
Some of the most dangerous cars on the strip are the older muscle, simply because they are the most likely to crash because of all the aforementioned reasons. And often they arent even that fast. And that's with all the approved so called safety features. They still dont make the vehicle safe from crashing going up the track.

but back onto the SC vs Turbo...although the graph of those 4 cars could have massively different setups etc...it does highlight one big misconception many have about a centri. Where many will say they do nothing at lower rpm's. Which is totally untrue. It's clear to see on those graphs that one isnt too far behind the Roots in terms of torque at lower rpm, despite seeing less boost.

And equally the twins graph....really not that impressive low down, but with no info on the setup....again, makes it sort of meaningless.

[mrimpala02]

Originally Posted by stevieturbo

Having seen pictures of some cages guys use...I think I'd be trusting the OEM safety cell they designed to keep the driver etc safe in a modern car.

Lets not forget, lots of the old rules are based around ancient pieces of crap with no brakes, terrible chassis, and generally dangerous cars to start with.

There are bone stock cars that exist now, that can easily exceed the traps/ET's for lots of their silly rules...and you can be sure a lot of the NHRA safety features...would in no way make those cars safer for 99% of their usage.

I'd far sooner race against a car with no cage, but sensible wheels and tyres....as opposed to a car with big wobbly tyres and skinnies up front, which mean they wont handle, and wont brake....and will go out of control very easily.
And of even more importance is the ability of the drivers...which is never checked. And there are some crazy fools out there.
Some of the most dangerous cars on the strip are the older muscle, simply because they are the most likely to crash because of all the aforementioned reasons. And often they arent even that fast. And that's with all the approved so called safety features. They still dont make the vehicle safe from crashing going up the track.

but back onto the SC vs Turbo...although the graph of those 4 cars could have massively different setups etc...it does highlight one big misconception many have about a centri. Where many will say they do nothing at lower rpm's. Which is totally untrue. It's clear to see on those graphs that one isnt too far behind the Roots in terms of torque at lower rpm, despite seeing less boost.

And equally the twins graph....really not that impressive low down, but with no info on the setup....again, makes it sort of meaningless.

Until you see crap like this: https://youtu.be/beuFXAn5J10

[stevieturbo]

And exactly what I'm referring to about wholly inappropriate tyres that make a car unstable and unsafe. And at 195mph as he is saying....no ****ing way should he be hitting the brakes. Allow the car to decel naturally before using the brakes. It WILL slow down extremely quickly anyway to a safe speed like 150+ where you can brake hard if needed.

And very clearly the OEM passenger cell did save those occupants, despite them also disabling the airbag systems in the car etc as there are no indications of those being deployed. ( presumably on such a modern car there would be multiple airbags ? )

[SSE 4 2SS]

Originally Posted by hunter1660

According to Google, only need roll cage if faster than 9.99 or 135 mph.

True in a hardtop.... However, if in a convertible as the gentleman I was speaking to is, then the rules are stiffer for good reason.... 11.00 - 13.49 will require a roll bar, faster than 10.99 requires a full cage.