Drivability blower vs turbos

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Twin turbos. Blowers use power to give/make power. Turbos make power off exhaust so it's basically free power. My gtr had twin turbos making lots of power and was very driveable (hell it was a daily driver for me).
 
both work well but as 1970Duster said the turbos work off the exhaust and blowers take power to make power
 
tqfastfish said:
cool, what turbos do you recommend, looking for mid 9s with the dart, I was looking at the turbonetics t4s
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Well, it depends what engine you're running and drivetrain components you use. From what I've read about turbos is they seem to like the high gear ratios that way they can build their boost better.
 
im leaning towards a big block built to about 550 horse + the turbos.... going to be back halved with a fab 9 or dana rear most likely a 3.55 gear or higher , I plan for it to be carbureted to.

if I go blower I was going to have indy build me a 426 inch gen 3 stroker
 
tqfastfish said:
im leaning towards a big block built to about 550 horse + the turbos.... going to be back halved with a fab 9 or dana rear most likely a 3.55 gear or higher , I plan for it to be carbureted to.

if I go blower I was going to have indy build me a 426 inch gen 3 stroker
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It also depends on the compression of the engine. As I said before, turbos like the low gear ratios. I'm no drag racer, but I've seen some people do better in the quarter mile with some 2.76 gears as it allows the turbos to build boost. Don't quote me on this stuff as I'm still probably a novice and this is just stuff I've read or seen on youtube. There's a member on here who's built a twin turbo small block stroker engine setup that made, I believe, 700+ hp. You might want to pm him (Mad Dog?).
 
I like blowers. if your thinking of gen 3 Hemi, have arrington build it for you, with a kenne bell twin screw. pure badass.

phuck Indy. they suck.
 
There is a very specific way to size a turbo. Involves a fair amount of math....T4 is just a mount style. Might want to spend a few weeks reading over at the TurboForums before pursuing this. If you are looking to build a consistent bracket car with a turbo you might want to google "bump box" among other things....
 
Gen 3 Hemis have no keyway on the crank to hold the harmonic balancer on. They rely on a press fit.
ProCharger has a pinning kit for use with centrifugal blowers.
If you run a Roots blower, have the crank double keyed before assembly.
Those 6-71 blowers take lots of HP to turn, but they look cool and make instant boost.
The screw type supercharged Gen 3 Hemis are quite impressive!
 
Ya 400-450" b motor with a s480 will get you where you wanna be. Then you gotta decide injection or blow through. If money isn't a option I'd go injection with the new holley injection. If you have a tight budget like me I run a quick fuel carb built for blow through. Its been very good although I am sure a CSU carb is better. How big of tire? I run a 315 drag radial and a 3.54 gear. For more of a street car I'd go a 3.0 or so. Make sure you get a converter set up for boost. Anti-balloon plates.. Hope that helped.
 
Use two turbos. If you're worried about lag or something run one big one and one small one. The small one will build boost while the bigger one is spooling up.
 
Ya 400-450" b motor with a s480 will get you where you wanna be. Then you gotta decide injection or blow through. If money isn't a option I'd go injection with the new holley injection. If you have a tight budget like me I run a quick fuel carb built for blow through. Its been very good although I am sure a CSU carb is better. How big of tire? I run a 315 drag radial and a 3.54 gear. For more of a street car I'd go a 3.0 or so. Make sure you get a converter set up for boost. Anti-balloon plates.. Hope that helped.
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Thanks, very helpful, I think I am going to run blow through because its cheaper and I like a old fashioned carb better. I am going to be running a 33x17.5 Hoosier pro street tires. I see a lot of people running mini tubs but not full tubs
 
I'd go 3.23 with that tall of tire. I also don't think mini tubs will clear that big of tire..
 
Turbo, although ideal is a fab it yourself deal and room/space is an issue.

You can get a bolt on procharger setup that will make 750-1000 HP and be very streetable. That is the direction i'd head...
 
tqfastfish said:
for compression I was thinking something like 8.1 I know it needs to be low
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8.1 will work but you're leaving a lot on the table.

You will make more horsepower per lb of boost than you will per point of compression. An all out race car may run very low compression and a very high amount of boost because they are not worried about throttle response with everyday driving. Since you are building a street car you want to move the compression up so it's not such a dog but not so much that you can't run very much boost without adding higher octane fuel.

I've found that a nice area to stay around for a street car is close to 9 to 1 compression. You can play with calculators computing your "Dynamic" compression ratio with expected compression ratio and boost to find where you are happy running on 93 octane. You need to decide how much power you will be happy with on the street on 93 octane vs at the track on race fuel.


Horsepower with engine size and turbos. You can make way more power than you need to run 9s on a smallblock with single or twin turbos. For instance. Let's say you build a 9-1 compression 360. This is a pretty simple motor but you've put good forged parts in it. With decent heads this motor should make around 300 rwhp. Now let's add a little science. Atmospheric pressure is 14.7 lbs. So for every 14.7 lbs of "boost" you are adding one atmospheric pressure. I usually round it to 15lbs to make the numbers easy. Take your 300rwhp 360 motor and add 15lbs of boost. You have now doubled the output and are close to 600rwhp. This is enough power to push a 3200lb car into the 10.teen range at around 130mph. All on 93 octane. If you change to a higher octane fuel for racing and run the boost up to around 20lbs let's look at the numbers. Engine makes 300 rwhp. 15lbs of boost adds 300rwhp so you're adding roughly 20hp per lb of boost. With 20lbs you would be adding 400rwhp to your original 300 NA RWHP so you'd be at 700rwhp. That's easily enough for a mid 9 second pass.

If you build a 9-1 compression 360 based 408 and make around 400rwhp NA you can run the numbers and see you will be easily in the low 9s around 145mph on 15lbs of boost and pump gas.


Turbos: You're turbo sizing is completely dependent on your motor choice and horsepower goals. There are common turbos that people run but even if you pick a size each size will have several variations. Depending on what you are putting this in you may end up running a single simply to make it fit. At the end of the day what you are looking for is CFM. Your motor will require a certain CFM to run NA. You are attempting to increase that so you need a turbo that will push the required CFM at a boost level it is happy with. You need to look at compressor maps and pick a turbo that will suit your build.

Gearing - Don't run such a high gear that the car is sluggish. Turbos do like long pulls but they also like rpm. Figure out how much power you're going to make. Calculate what your trap speed will be. Pick a gear that put's you just under redline on the tire you will be running for the target trap speed. Autos and turbos are made for each other.

You have a lot of research to do but it's not rocket science. I hope I've been able to shed some light on it for you.
 
MuuMuu101 said:
It also depends on the compression of the engine. As I said before, turbos like the low gear ratios. I'm no drag racer, but I've seen some people do better in the quarter mile with some 2.76 gears as it allows the turbos to build boost. Don't quote me on this stuff as I'm still probably a novice and this is just stuff I've read or seen on youtube. There's a member on here who's built a twin turbo small block stroker engine setup that made, I believe, 700+ hp. You might want to pm him (Mad Dog?).
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I think you mean "mad dart" and I don't think he has run the twin turbo SB stroker yet with the snails. Last I saw he had the stroker in his pro street Dart N/A with some spray and is terrorizing the streets of SoCal.

I wouldn't trust Indy to build me an engine. Nope, NFW.
 
Personally I'd talk to a guy a shady dell speed shop here in state college pa his name is Ryan Johnson and he knows his Turbo and supercharger and small block stuff. He has built the 540 in my dads power wagon with a f2 procharger and he has a 417 turbo engine making 1300+hp and he also has a 521 small block on the dyno right now that's on methanol so id give him a call and pick his brain on this matter

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