Turbo vs. Nitrous

[theone61636]

As i sit here pondering what I'd like to do with my Riv, I can't help but wonder what would be best for my situation.

Current Engine: Rebuilt 72 455 Block, 10:1 Forged Pistons, Oil Mods, Stock Rods w/ARP Bolts, Lightly Ported Stock Heads, Edelbrock Performer Intake with Holley Carb, a TA 288-84H cam, and stock manifolds.

When I get home from deployment, my 72 Riv GS will become my daily driver as i soupe up my 06 GTO. I have no idea what kind of power the engine makes, as i have yet to drive it, and was originally going to fuel inject it, turbocharge it and throw and overdrive trans into it. But, i don't know if that turbo would be overkill on this engine. I want to make, at most 550hp at the crank, so i think a single turbo wth low boost could do that easily. And with fuel injection the addition of a turbo wouldn't make such an impact on gas mileage until i romp on it. But, the extra power will require extra fuel so I don't know if i would be better off just getting a nitrous sytem to use when and if i ever want that extra power.

Definites:
Retrotek Powerjection III Fuel Inj System
Built 200R4 with Lock UP converter

So, what do you guys think? Turbo on low boost or nitrous? Also, any ideas on what kind of horsepower the engine is currently making?

[Nothingface5384]

the turbo system would be cheaper in the long run
turbos, like a 4barrel will actually improve gas mileage when youre not in it..but when youre under boost say goodbye

[carmantx]

what to do, what to do.

Race car? Use nitrous.

Driver? turbo.

Seems like your compression ratio is a little high for turbo, except maybe low boost. Good thing about a turbo for you would be the power you would always have access to. Not just when the bottle is open and ready.

Just my humble, worthless opinion.

We will be adding nitrous to the 70 Skylark before next season, and building a turbo motor for the other car. The GN is alread turbo, so we will have some of each.

[Running]

Procharger would be another good choice.

[Nothingface5384]

yes it would, and oops didnt even seem the 10.1 cr thats mean youre kind of limited to about 6spi maybe 8 with alki injection and or intercooler

[Heavy D]

Both! :Brow:

[theone61636]

Procharger would be another good choice.

If it wasn't so expensive, I would've gone with a Procharger setup. But, I was going to build my own turbo system and i priced it out to about 1700 and that includes all the hot pipe fab work i would need someone else to do for me.

[theone61636]

As far as the C.R. goes, i was going to get some thicker head gaskets to lower it a little along with some head studs to keep things tied down under boost, but again, I'm pretty sure 6-8lbs would be fine on even a 10:1 motor, espcially since I'll be using fuel inj.

[sean Buick 76]

As far as the C.R. goes, i was going to get some thicker head gaskets to lower it a little along with some head studs to keep things tied down under boost, but again, I'm pretty sure 6-8lbs would be fine on even a 10:1 motor, espcially since I'll be using fuel inj.

You can get Commetic head gaskets VERY thick although your intake will need to be modified to match. You will want to either swap out pistons if you go Turbo in my opinion unless you can get down to 9.5:1 or less.

I say add a block girdle, get the compression down to 8.5:1, intercool it and run 14 psi of boost as well as a 100 shot of nitrous to help keep things cool! Nitrous comes out VERY cold.... I am using it on my turbo engine since nitrous and turbos are like butter is to bread!! Can you say 900 hp+ street car?

[Justa350]

Sean, Sean, Sean. You and your huge HP numbers!

I say, get a nitrous kit and have at it. You can have some fun for now, and start pulling the parts together for the turbo build.

[sean Buick 76]

Sean, Sean, Sean. You and your huge HP numbers!

I say, get a nitrous kit and have at it. You can have some fun for now, and start pulling the parts together for the turbo build.

Well its not hard to make 900 with with a 455 engine that makes 500 NA LOL!

[Turbo455]

Turbo! Turbo! Turbo! Turbo!

[sean Buick 76]

Here is a good comparison for you, this guy used a 10:1 engine beefed it up a bit and added thicker head gaskets to get him down to 9.3:1 then added 12 psi of boost:


Hey, I finally have some results in. I dont have any dyno graphs yet but ill post them whenever i get the email from Jim at PAE.
Check my signature to see my engine combo.

On motor @34* it made 443 hp at 5000 rpm and 560 torque.

The procharger dyno is not completely done yet as the rpms have not been taken high enough to find out where the hp peaks at, but,
@ 5800 rpm and 24* of timing it put out a measly 685 hp and 710 torque, so far.

Update here:



Update, my cap button and rotor were burned due to running a digital 7 ignition system on it so Jim upgraded it to handle the digital 7.

Like posted above, it made 685 hp and 710 tq at 5800 rpm.
Now, with the upgraded rotor busing and button, it makes a litlle more power.

767 hp and 730 tq and 5900 rpm and the power still has not peaked so far.

He is make the final 3 pulls this afternoon. He will be dropping the timing from 24 to 21 degrees and taking the rpm's a little higher to see what it does and that will be it for now till hits the chassis dyno after the nats.

Ill post up the final results from him, which is how the motor will be at the nats, tomorow.


Add Turbos, intercooling and a few more PSI and you would have quite the beast!

[theone61636]

Don't get me wrong, I would LOVE to go for the big power numbers, but that's not what I bought this car for. I bought this for cruising and going to and from work. A 500-550 hp car is just about at the edge for what i would consider a daily driver and the only reason I want that much is because my GTO spoiled me. So now every car i drive has to be at least that fast.
Besides, to tell you guys the truth, if I wanted to go for big horsepower numbers, I'd use an LS motor, since they're proven to be reliable at those levels. Even with all the band aids for the 455, its still luck of the draw keeping one together and for the price of just the aluminum 455 block i could have a forged LSX short block motor capable of handling 1000+ hp.

[sean Buick 76]

Don't get me wrong, I would LOVE to go for the big power numbers, but that's not what I bought this car for. I bought this for cruising and going to and from work. A 500-550 hp car is just about at the edge for what i would consider a daily driver and the only reason I want that much is because my GTO spoiled me. So now every car i drive has to be at least that fast.
Besides, to tell you guys the truth, if I wanted to go for big horsepower numbers, I'd use an LS motor, since they're proven to be reliable at those levels. Even with all the band aids for the 455, its still luck of the draw keeping one together and for the price of just the aluminum 455 block i could have a forged LSX short block motor capable of handling 1000+ hp.

Perfect if you make about 400 hp NA then you only need a small shot of nitrous or a few psi to meet your goals.

[buick46270]

For just a daily driver and only wanting 550 max, just stick with the nitrous unless your dead set on boost. Trust me, ive procharged a buick 455, and now a turbo lsx motor.

You can buy a complete nitrous plate kit with all the safety stuff for around $500, a turbo will go much more than that. My turbo, wastegate, and blowoff valve cost $1300 allone. Add in whatever manifolds youll use for the turbo, blow through carb, fuel pump, piping, intercooler, etc etc and itll end up getting costly.

But in the long run just do whaever you like and what you want, i could have saved alot of money on my last two motors by just using nitrous, but ive gotten addicted to boost and love having the power on tap and never running out...i do race my car usually twice a week, and is a daily driver, but we all have our own interpretations of a dd or street car

[Nitro71455]

I went the Nitrous route first, then ended up going boost about 6 years ago... Nitrous can get to be a pain in the butt to fill up all the time. It's nice to always have boost on tap......

[theone61636]

Well, if i go turbo, i was planning on going with a single. I'd rather do duals but i don't think i can fit them without removing the a/c. Has anyone done dual turbos and kept the a/c? Where did you put the passenger side turbo, where the battery is? Also, I was looking at using a Holset HX40W for my single application, has anyone had any experience with this turbo?

[Tyler Northcutt]

Well, if i go turbo, i was planning on going with a single. I'd rather do duals but i don't think i can fit them without removing the a/c. Has anyone done dual turbos and kept the a/c? Where did you put the passenger side turbo, where the battery is? Also, I was looking at using a Holset HX40W for my single application, has anyone had any experience with this turbo?

Well, there is no reason to go twins, unless you just really like the look of it.

[sean Buick 76]

Well, there is no reason to go twins, unless you just really like the look of it.

Except that there are many advantages of Twins if you can fit them. More efficient routing, quicker spooling due to two smaller turbos vs one larger one ect.

[sean Buick 76]

Well, if i go turbo, i was planning on going with a single. I'd rather do duals but i don't think i can fit them without removing the a/c. Has anyone done dual turbos and kept the a/c? Where did you put the passenger side turbo, where the battery is? Also, I was looking at using a Holset HX40W for my single application, has anyone had any experience with this turbo?

I have a book here called " TURBO rear world high-performance turbocharging systems", it has tons of info on how to pick the best turbo for your needs. Included are compressor maps of the hx40w which can help you in your effort.

[Tyler Northcutt]

Except that there are many advantages of Twins if you can fit them. More efficient routing, quicker spooling due to two smaller turbos vs one larger one ect.

It is also alot more money to spend.

2 turbos vs 1, is it really going to spool up faster? If you get a single turbo with the correct A/R you will not have any issues with a slow spool up.

[sean Buick 76]

It is also alot more money to spend.

2 turbos vs 1, is it really going to spool up faster? If you get a single turbo with the correct A/R you will not have any issues with a slow spool up.

Like you say, correct pick of a turbo (s) and other system aspects will create a good system function with no "lag" problems.

If someone has room for a large turbo, and does not mind routing the exhaust to one side of the engine then the single is a good option. Inline engines for example are better suited to single turbos vs a V8 that has big cubes and exhaust on both sides.

One major advantage that the twins have to me is that they leave me with a true dual exhaust in a managable 3" diameter. For race only cars this is less important since they may only run a 6" downpipe but I like full dual exhaust on my street cars for the V8 rumble.

Keep in mind though two smaller turbines have lower polar moment of enertia than a single larger turbine to create the same power. I will not bore you with the proof in numbers. Quicker spooling with two smaller turbos vs one large one.

What is REALLY cool is the tractor pullers who use turbos feeding each other to create over 100 psi of boost!

[carmantx]

hmm. 100psi. Guess we will need a girdle, halo, and trash can for all the little pieces left of the block.:eek2:

[Turbo455]

I say use a single if it fits your needs. A single will spool slower. But a properly sized turbo should spool fairly close to a set of twins. It's kinda like say my dog is bigger than yours because my dog weighs 101 pounds and your dog weighs 100 pounds. They are both big dogs, and yes I chose big dog analogy on purpose. In other words at the end of the day with a single or a twin you will be driving the big dog.

[sean Buick 76]

Here is a big dog LOL.... 2000 hp street car

http://www.youtube.com/watch?v=gN6E-_0wXos

[Justa350]

Ha, no kidding! It would be fun to watch come apart in a dyno cell, with high speed cameras though!



hmm. 100psi. Guess we will need a girdle, halo, and trash can for all the little pieces left of the block.:eek2:

[BuickRacer69]

Its easy to make horse power on paper....


Sean, Sean, Sean. You and your huge HP numbers!

I say, get a nitrous kit and have at it. You can have some fun for now, and start pulling the parts together for the turbo build.