Combo suggestions for 550-600 rwhp

Personally? Build a bullet proof bottom end. Just add Thumper or GT40 heads with a cheap Cobra intake,cheap stock cam, and get a Hellion Turbo! With this Turbo set up you even get to keep your AC And you will meet and exceed your HP expectations! (not too mention gobs of torque) You will have a mellow idle,good gas mileage,AC for those hot summer days and the ability to smoke 95% of the cars out there on the street!! Just dont forget to beef up the rest of the drive train.

SSBLUBYYOU said:

I realy haven't given turbo much thought do to the time it takes to spool up and make power....I guess turbo's have realy came a long way. I don't realy care for the sound they make when they blow off...I know that sounds crazy but it reminds me of the ricers running around. What makes you say use GT40 or Thumper heads and a stock cam with a Cobra intake? Wouldn't' there be a lot more power to be had with AFR's, Trickflow, or some other head/intake combo along with a custom cam? I realy apreciate all the comments...I want to do this right the first time and not waste a ton of money doing it twice. So which block would be the way to go...bang for buck? Also this combo must run off of 93 octane pump gas and emissions are not a concern if that helps!

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You dont need the expensive supporting mods to make HP/Torque with a turbo.Just good durable parts.The stock cam is a good boost cam and delivers good gas mileage.And yes,turbo's have come a long way.Auto or 5spd?
Isaw a test with Hellion with this same set up.Bullet proof bottom end,GT40 heads + intake and an e cam I think. It made over 700HP using only like 11-13 lbs of boost. Too me,that enough HP for the street. HP Turbo's and Hellions are really good!

Yes, i would opt to go with a turbo set-up over the supercharger. They are the way to go, plus when your foot isn't mashed into the floor the turbo provides better gas mileage than it would did it not have a turbo.

you had a 00 camaro that made 529 rwhp, which would mean over 600 at the crank, am i right?? then you should pretty much know what it takes; how were you making 600 hp before?? fuel system,heads,cam,bottom end,poweradder??etc.

The only downside to a turbo and a manual tranny is the hole shot! You cant spool up boost with a 5 spd off the line.Automatics are waaaay better for turbo's in that respect. It wont spool up without a load on the motor.An auto can do this.But if you not a serious track racer I wouldnt worry about it.,

The fastest guys running turbo's do tend to have auto's. That's not to say though you can't build boost on the line with a manual. The 2-step aids in this area by retarding timing...creating more heat and artificially spooling the turbo's.

As far as trannys go...you can go either a tko or t56 would be fine. That's not to say that you wont break them....it's just a bit tougher. Also, with a turbo setup your going to want to run somewhere around a 3.27 rear end gear. Due to the turbo's being load based, the lower numerical gear helps build boost quicker as well. This also helps keep the rpms down on the freeway...which makes a 6-speed that much less important.

I take it you have never been in a turbo vehicle. Unlike centri superchargers, properly sized turbo's build boost quicker and hold it thru redline. As such, you should'nt have a problem reaching full boost by 3000 rpm.

For more information...do some searching on www.turbomustangs.com

A word to the wise: don't build a 550+ rwhp street car with a stock 302 block. Go aftermarket or go home.

If I were shooting for 550+ rwhp for cheap, I'd lean towards a high compression (12:1), high revving, stroker 408 with AFR 225s, and a custom cam (hydraulic possible, but solid roller preferred) setup with perhaps the TFS-R intake. I'd look really hard when deciding whether to go carbed or not. And for a corner carver it isn't ideal, but I'd personally rather road race a naturally aspirated 351 than a turbo-charged Dart-blocked 302. I'll bet someone out there is thinking that a 351 weighs more than the 302, but they'd be mistaken without taking into account the extra 150 lbs aftermarket 302 block + the weight of a turbo or two and its kit.

I don't see how you could build boost with a 2 step, either. The engine is nothing but a heat pump. At a certain volume of fuel/air, is going to make a given amount of power. It only takes a given amount of power to "free-rev" the engine on the line. With more load, you can use all of the power an engine makes, thereby pushing more air through the turbine, thus spooling the turbo.

No timing retard alone is going to cause a turbo to spool on the line without load. For a turbo to spool, means that it is forcing air into the engine. If that's the case, the fuel system must compensate by injecting more fuel, else there would be a catastrophic lean condition, which undoubtedly would cause engine damage. With said air and fuel being forced into the combustion chamber, the engine is going to make more than enough power to spin the engine well beyond its operating rpm range.........unless of course there is enough load present to "hold" the power the engine is making, and prevent it from increasing in RPM.

millhouse said:

The fastest guys running turbo's do tend to have auto's. That's not to say though you can't build boost on the line with a manual. The 2-step aids in this area by retarding timing...creating more heat and artificially spooling the turbo's.

As far as trannys go...you can go either a tko or t56 would be fine. That's not to say that you wont break them....it's just a bit tougher. Also, with a turbo setup your going to want to run somewhere around a 3.27 rear end gear. Due to the turbo's being load based, the lower numerical gear helps build boost quicker as well. This also helps keep the rpms down on the freeway...which makes a 6-speed that much less important.

I take it you have never been in a turbo vehicle. Unlike centri superchargers, properly sized turbo's build boost quicker and hold it thru redline. As such, you should'nt have a problem reaching full boost by 3000 rpm.

For more information...do some searching on www.turbomustangs.com

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FastDriver said:

I don't see how you could build boost with a 2 step, either. The engine is nothing but a heat pump. At a certain volume of fuel/air, is going to make a given amount of power. It only takes a given amount of power to "free-rev" the engine on the line. With more load, you can use all of the power an engine makes, thereby pushing more air through the turbine, thus spooling the turbo.

No timing retard alone is going to cause a turbo to spool on the line without load. For a turbo to spool, means that it is forcing air into the engine. If that's the case, the fuel system must compensate by injecting more fuel, else there would be a catastrophic lean condition, which undoubtedly would cause engine damage. With said air and fuel being forced into the combustion chamber, the engine is going to make more than enough power to spin the engine well beyond its operating rpm range.........unless of course there is enough load present to "hold" the power the engine is making, and prevent it from increasing in RPM.

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You need to understand a bit more of how a turbo works I suppose...and perhaps a 2-step. What the 2-step allows you to do is rev to a given rpm...and while doing so it drops the ignition to certain cylinders. The fuel then gets burned in the header/turbo turbine which builds boost. Remember, the turbine moves due to heat exchange over the turbine blades...not from backpressure. Retarding the timing while using the 2-step further aides building boost on the line (more heat).

Now...while on the 2-step with boost...your certainly pushing air. While a supercharger can free rev and build boost with no load...a turbo cannot. Simply reving the engine does nothing for boost in turbo applications.

millhouse said:

You need to understand a bit more of how a turbo works I suppose...and perhaps a 2-step. What the 2-step allows you to do is rev to a given rpm...and while doing so it drops the ignition to certain cylinders. The fuel then gets burned in the header/turbo turbine which builds boost. Remember, the turbine moves due to heat exchange over the turbine blades...not from backpressure. Retarding the timing while using the 2-step further aides building boost on the line (more heat).

Now...while on the 2-step with boost...your certainly pushing air. While a supercharger can free rev and build boost with no load...a turbo cannot. Simply reving the engine does nothing for boost in turbo applications.

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whats a 2 step can you explain a little more or give a link it would b great.

rickd93_lx said:

whats a 2 step can you explain a little more or give a link it would b great.

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+1

rickd93_lx said:

whats a 2 step can you explain a little more or give a link it would b great.

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Think of it as an on demand rev limiter. You set the rev amount to the desired rpm and wire up the switch to either a button...or in the case of a 5-speed, the clutch. When the switch is activated (push button or clutch in) the 2-step limits the rpm by cutting spark to the cylinders. Once you release the button or clutch, the 2-step deactivates and the rev limiter is back to stock.

Here is another neat thing that a 2-step can do for ya. Lets say you set it to 4000 rpm. Now, your at the tree on the strip....you have the clutch in (activated 2-step) and the throttle is to the floor. Your rpm is steady at 4000...and if you have a turbo your already building boost. The last amber light comes...you dump the clutch and the 2-step is deactivated. Now...the fun begins when it's time to shift again. Guess what happens if when you decide to powershift? The clutch goes in...activating the 2-step, dropping the rpms to 4k rpm and your foot never has to let off the accelerator pedal.

millhouse said:

Think of it as an on demand rev limiter. You set the rev amount to the desired rpm and wire up the switch to either a button...or in the case of a 5-speed, the clutch. When the switch is activated (push button or clutch in) the 2-step limits the rpm by cutting spark to the cylinders. Once you release the button or clutch, the 2-step deactivates and the rev limiter is back to stock.

Here is another neat thing that a 2-step can do for ya. Lets say you set it to 4000 rpm. Now, your at the tree on the strip....you have the clutch in (activated 2-step) and the throttle is to the floor. Your rpm is steady at 4000...and if you have a turbo your already building boost. The last amber light comes...you dump the clutch and the 2-step is deactivated. Now...the fun begins when it's time to shift again. Guess what happens if when you decide to powershift? The clutch goes in...activating the 2-step, dropping the rpms to 4k rpm and your foot never has to let off the accelerator pedal.

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Good for power shifting but still dont see how it puts a load on the motor!

GTOReturns said:

Good for power shifting but still dont see how it puts a load on the motor!

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See my previous post in responce to FastDriver. If you still dont get it, you'll need to do some research on the inner workings of turbo's in general.

http://www.turbomustangs.com/turbotech/main.htm#turbocharger_theory

millhouse said:

You need to understand a bit more of how a turbo works I suppose...

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Thats the sort of comments that makes arguments personal... I'll bet I understand a turbo as well as anyone here. I'm looking at this purely from a physics standpoint.

and perhaps a 2-step.

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You seem to have me, here.

What the 2-step allows you to do is rev to a given rpm...and while doing so it drops the ignition to certain cylinders. The fuel then gets burned in the header/turbo turbine which builds boost.

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Gotcha. The fuel burns after it's let into the headers, which has the same effect as normal combustion, except the thermal energy isn't converted into kinetic energy, because the combustion doesn't happen in the cylinder.

Remember, the turbine moves due to heat exchange over the turbine blades...not from backpressure. Retarding the timing while using the 2-step further aides building boost on the line (more heat).

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No, not really. Sorry for being an ******* and correcting you, but you told me that I don't understand how a turbo works so..... Heat exchange around the blades doesn't add anything to the speed at which they turn. The heat expands and pressurizes the air which forces its way passed the turbine blades and imparts a force. This works because the air-pressure acting on the surface of each turbine wheel creates a moment about the central axis of the turbine.

Backpressure, in this case, would be the pressure acting behind the turbine (on the side opposite the exhaust valve). It's the net pressure difference before and after the turbine, and the kinetic energy imparted from the flow of air into the turbine that creates the rotational force necessary to drive the compressor wheel. Heat is the cause of that force, but it is not a direct conversion from Heat energy to rotational energy.

The conversion is from heat energy to air compression follows: Heat is molecular kinetic energy. The closed system before the turbine channels the kinetic energy toward the turbine simultaniously increasing the pressure of the air on and before the turbine, which causes a linear force imparted on each blade, which imparts a moment about the fixed axis of turbo, which imparts a force to the blades in the compressor, which imparts a force on the air touching each compressor blade. That air is forced into a smaller volume, which in turn causes the pressurization/density of the air.

Now...while on the 2-step with boost...your certainly pushing air. While a supercharger can free rev and build boost with no load...a turbo cannot. Simply reving the engine does nothing for boost in turbo applications.

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That makes a lot of sense. The reason a supercharged engine doesn't "run away" is because the boosted air in the intake tract is blocked by the throttle body. The same motor naturally aspirated uses a little more throttle to free-rev the motor to 6000 rpm, but roughly the same amount of fuel/air. If, in a turbo, you block the air, there will not be enough exhaust flow to spool the turbine. It makes sense, though, that if you burn the fuel in the header before the turbine, or late enough in the combustion cycle to do any meaningful work that you can get enough energy to spool the turbo. So instead of blocking the air/fuel, the two-step allows you to let it in, cuts off ignition to most of the cycles and lets it burn in the exhaust or burns it late in the combustion cycle...

Ps. It seems most people are only able to spool the turbo enough to get a small amount of boost (usually 4-6 lbs) using a two-step and timing retard. Still, the majority of spool-time is getting the turbo to spin fast enough to go from a slight vacuum, less than an atmosphere, in the intake to a positive pressure.

Anyway, thanks for the explanation. My problem in understanding came from not knowing how the two step drops ignition or retarding combustion as much as it must.