VG30TT/LS1 (corvette) swap

[Guest Slack00]

I could not find any references to it using the search tool, so I apologize if this has been asked before.

 

I may be recovering an entire C5 drivetrain (with the six speed), complete with the rear mounted trans, from my C5 which has been totalled.

 

1) I understand the LS1 will fit readily, but I assume these were all Camaro motors and transmissions; can the Corvette driveline be used in the Z32?

 

2) Secondly, if I use the TT version of the VG30, will I be able to retain the turbos? (I understand, of course, the exhaust manifolds would have to be different, etc,but what about the rest of it?)

 

Thanks a million for all your help!

[wheelman]

I guess the standard answer here is that with enough money, time and skills anything is possible.

 

OK now that thats out of the way I would think getting the Corvette tranny to fit in the rear of a Z32 chassis would be a major fabrication job. LS1s have been transplanted into at least 2 Z32s that I know of so that part is a known. If I were you I'd sell the vette rearend and get a T56 to mate to the LS1.

 

Just my .02 worth although tranplanting the full vette drivetrain would surely make a very unique car.

 

Wheelman

[Guest shadow z]

A guy from my home forum (300zxclub.com) has the 6spd in his LS1 Z32.

He informed me that the "bell-well" in the fire wall needs to be pounded back 3" for fitment.

 

no more fabrication needed except for the engine and tranny mounts, which can be done by any competent shop.

[Guest Slack00]

Yes, well, if I was using the rear mounted transmission, I (probably) wouldn't need to bang 3" out of the front firewall. Maybe I could even fit the engine a litte further back...

 

The question is, will I need to bang out the rear 'differential-well' to accomodate the transmission?

 

Selling the Corvette 6spd transmission rear end is not a bad idea, but 1) I dunno if I could find a buyer real easy, and 2) I dunno how the Corvette LS1 would mate up to the T56 from a Camaro...I dunno even know how it mates up the the torque tube it has now!

[Lone Star 1]

Y body ls1 Is nearly the same as an F body ls1. Main differance is the pully setup on the Y body ls1 runs about a 1" closer to the motor .They use the same block.Will the transaxal fix, I have know idea, but I assume any thin is possible!

[Guest Slack00]

Yes, of course they are the same engine...(hence they are both called the LS1)...but I know there are other differences as well...for example, the Corvette LS1 has the 'batwing' oil pan that the Camaro LS1 does not...and the cams are different, of course. So I can't just assume that a Camaro T56 will mate up to a Corvette LS1...can I? Does the torque tube mate up to the Corvette LS1 the same way that the T56 would? I don't know. I suppose these are questions for LS1.com...

[KraZeeZX]

Hi.. I'm one of the guys running around with an LS1 z32 and I can tell you that adapting that Vette transaxle would be one helluva project.

 

I originally bought a Vette transmission and the seller neglected to tell me about the transaxle setup so I ended up having to sell it and find an F-body tranny.

 

After seeing that transmission and an entire C5 transaxle setup, I can tell you that it will be MUCH MUCH easier on you and your wallet if you sold it and went with an F-body trans. Withe the transaxle you will have to pound out the firewall like i did and also the driveshaft tunnel. As far as fitting the transmission in the rear... there's a bit of horizontal room, but I don't think that transmission will have enough ground clearance since the fuel tank is basically right above where the differential currently sits.

 

If you had the time, money and patience.. more power to ya, but for a swap that you KNOW will work and will save you extra money.. just find a nice T56 out of a camaro or trans am and mate that up.

 

As far as matching up an Fbody trans goes.. I would guess there is an adaptor or a piece that will convert the torque-tube over to the proper bellhousing setup.. I'm not quite sure how differently they mate, but I am positive you can setup a Vette LS1 to use an Fbody T56. Like you said.. to get a straight answer.. the best place as of now would be LS1tech.com and go to the conversions/hybrids forum or just into the drivetrain forum.

 

OH.. also.. the Vette oilpan wont clear the front crossmember in the Z32. I ended up having to go with an Fbody oilpan which ended up working after I had moved the firewall back.

 

Good luck whichever route you choose.. oh, and sorry out yor Vette!

 

-Vann

[Guest Slack00]

Thanks, KraZeeZX; that's exactly the kind of advice I was looking for. And there is none better than from someone who has had first-hand experience. I'll look into the T56 setup...someday I may be asking for photos and more advice.

 

What about the turbo plumbing? I see you are going to run a single turbo, so I assume your 91 Z32 was orignally a non-turbo? Do you think the TT setup from the VG30 would easily 'mate up' to the LS1 (aside from the obvious changes, like new exhaust manifolds)? Any clearance or sensor issues, I mean?

[KraZeeZX]

Thanks' date=' KraZeeZX; that's exactly the kind of advice I was looking for. And there is none better than from someone who has had first-hand experience. I'll look into the T56 setup...someday I may be asking for photos and more advice.

 

What about the turbo plumbing? I see you are going to run a single turbo, so I assume your 91 Z32 was orignally a non-turbo? Do you think the TT setup from the VG30 would easily 'mate up' to the LS1 (aside from the obvious changes, like new exhaust manifolds)? Any clearance or sensor issues, I mean?[/quote']

 

You're right, my Z was non-turbo originally. There's no room for a traditional turbo setup unless the frame is cut into. I'm actually going to be going with a rear mounted turbo setup which is all the rage these days. It's easy, it fits and it'll get done quickly and add a good bit more hp to my Z.

 

-Vann

[Guest Slack00]

What? Rear? Like near the muffler or what? Certainly that would introduce even more lag, would it not? Not to mention the lengths of plumbing you'd need. Sounds like a highly inefficient setup; please, convert me...

[Mike kZ]

I believe he is talking about this: http://www.ststurbo.com/home

[Pop N Wood]

That ststurbo site is kind of humerous. I don't doubt their kit does everything they say it does, but it is funny how they take drawbacks and try to spin them as positives. They brag about how much cooler the turbos run with a remote mount. Undoubtably true, but that just shows how much exhaust heat is being lost before it gets to the turbo. Guess if you are happy with the HP gain then it won't matter that things are being done inefficiently. It does have a lot of positives going for it.

[Guest Slack00]

I'm sorry, I don't understand...and heat is good for a turbo....how? A turbo only wants exhaust gas velocity.

 

My only concern is the increased lag...but actually, the advantages of the system seem to outweigh the disadvantages...no turbo timer, cooler temperatures, ease of mounting, added stealth, no need to scavenge four different pipes (in the manifold)....especially the heat thing: that is the arch-enemies of a turbo system....and this is a simple, effective solution...and, in terms of engineering, those are always the best solutions.

 

I just wonder if you can put two turbos on if you have a true dual exhaust....probably so....that could reduce some lag if you are willing to shell out the bucks...

 

But $4000 isn't necessarily cheap for a turbo system....in fact, that's about right...but, of course you don't have to buy their system; is anything proprietary about their idea?

 

I do laugh when they say they save gas mileage...somehow I seriously doubt that claim when you are PUMPING MORE AIR AND GAS at any given engine speed into the engine....

[Pop N Wood]

I'm sorry, I don't understand...and heat is good for a turbo....how[/i']? A turbo only wants exhaust gas velocity.

 

No, heat is energy. It is the expanding hot gasses that power the turbo. That is why high $$ turbo systems do things like ceramic coat the pistons and often run iron heads instead of aluminum. The more energy you can retain in the exhaust the more you have available to pump air.

 

But like I said, this system might be sufficient for the guy who just wants a slight boost and who isn't worried about building an all out race machine.

[KraZeeZX]

ugh... I guess I should have never opened my mouth.

 

it's efficient enough to give a substantial boost in hp. I'm not spending $4 grand on mine since STS doesnt make a specific kit for a Hybrid LS1 Z32.

 

I dont have any room in the engine bay.. so... this is a better option. Besides.. all the plumbing will actually be similar to whats already under the car. Manifolds, Y-pipe.. into turbo then from turbo to intercooler then from intercooler to intake... so, I'll have 2 long pipes running underneath my car like I do now with my dual exhaust.

 

This is just another way to make my car more unique.. and gain some nice hp to boot. I'm not trying to run 600psi on my car and have the fastest thing on the planet. I'm not looking for boost at 1000rpm. It's a simple, affordable (the way I'm doing it), unique mod that will provide me with more fun, oohs and ahhs.

 

Ive seen dyno charts and Ive seen track passes.. these rear turbo setups do their job. Would you pass up the chance to gain nearly 200rwhp for ~$1000 ???

 

-Vann

[KraZeeZX]

 

But like I said' date=' this system might be sufficient for the guy who just wants a slight boost and who isn't worried about building an all out race machine.[/quote']

 

 

Thank you! ... for everyone who is skeptical.. READ THIS COMMENT over and over again.

 

Me = guy who wants to run slight boost, not build an all out race machine

 

Vann

[Guest MelinaZX300]

Now,

 

I must have asked this question about 3 times with no good response. While we're on the topic and you guys seem to be in tune to this sort of swap, Is it possible to do an LS1 T56/(or maybe TH350,... 700r4) Swap into a Z31 1986 300zx. I understand that the motor mounts would have to be changed, and that there would be alot of fabrication, but my biggest concern is that this engine and transmission fits into the car without "Banging Walls." Also,... how do you reconnect this electronic engine and ECU back up to get everything or the most important things functioning in a car as complex as a Z31 or Z32. This is what really baffles me. Its obvious that the driveshaft may need to be shortened and the exhaust may need relocation. What I guess I'm really asking is that can someone with technical experience really pull this off and in a timely fashon, or is this going to be a project I'm going to hate myself for doing?

 

Dan

[Guest Slack00]

No' date=' heat is energy. It is the expanding hot gasses that power the turbo. That is why high $$ turbo systems do things like ceramic coat the pistons and often run iron heads instead of aluminum. The more energy you can retain in the exhaust the more you have available to pump air.

 

But like I said, this system might be sufficient for the guy who just wants a slight boost and who isn't worried about building an all out race machine.[/quote']No, heat is wasted energy. Heat does absolutely nothing to turn the turbine. The turbo is a mechanical device, not a thermal one. It uses kinetic energy from the moving exhaust gases to compress intake gases. The heat is merely a byproduct of combustion, and, in an ideal internal combusion engine, would be absent completely.

 

...but I understand what you probably were thinking. Heat energy causes pressure to rise (Pv=nRT), which, in a space like a long open tube (exhaust sytem) help to propel gases out the open end. However, it is not heat itself but merely the velocity of the gases that propel the turbine wheel impeller.

 

The ceramic coatings are applied to turbos to ensure longevity and prevent catastrophic destruction of the turbo due to expansion of components or warpage; they do nothing to make it spool faster. In fact, theoretically, any coating or additive to an impeller wheel will increase it's mass and make it spool slower.

 

As for coating your pistons in ceramic, that's somewhat of a mixed bag. Ceramic has a low coefficient of thermal conductivity, meaning it doesn't transfer heat. But now your well designed cooling system can't do its job very well, and your head temperatures get HUGE. The combustion chamber is now KEEPING all that heat, rather than it being dissipated through the walls in your cylinders to the cooling system. And that's BAD. Sometimes the spark plug tip will melt....sometimes it just stays so hot you get premature detonation (!). A HOST of bad things. Depending on how zealous you get with the coating, its VERY easy to melt every head gasket you have, (copper or no) not to mention your valves and everything touching the path of your exhaust gases. I have read studies that show that, in naturally aspirated engines, it actually REDUCES power because the heat is so great that it affects the pressure of the intake charge (lowering it and reducing power). This is why high revving engines are so hard to design and are so inefficient: as the gases get hotter at high rpms, it affects everything to decrease efficiency (expanding parts, extreme wear, spark timing adjustments, etc etc). In boosted engines it's not better...increasing the pressure of the gas increases the heat (more bad news) unless you have a very efficient intercooler. Its not so bad when your car is running, but when your car is stopped, the cooling system isn't operating and your temps get HUGE.

 

Iron has a thermal conductivity that is worse than aluminum, but that's not why hot rodders use it. They use it because iron does not warp under the intense heat as readily as aluminum. Aluminum cannot take the temperatures that a (heavily) boosted engine generates without warping somewhere.

 

Make no mistake...heat is baaad.

[Pop N Wood]

Well, no. Not trying to be condescending or get into a pissing contest of any kind. Just want to see the correct information in the posts.

 

The idea that the exhaust velocity is what moves the turbine is a common misconception. It is a somewhat confusing discussion since the exhaust is accelerated in the turbine stage as it is allowed to expand. But make no mistake, the hotter the exhaust charge, the more energy it contains and thus the more work that can be extracted from it.

 

Pick up a thermodynamics book and read the sections about the Carnot cycle, specifically the concept of enthalpy. This link may be a bit esoteric but it is well hyperlinked to understand the concept of a heat engine.

 

http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/heaeng.html#c1

 

Another way to think of it is it is the heat being released by the gas burning in the combustion chamber that powers the engine in the first place. Not hard to figure that this same effect occurs in the turbine stage of the turbo.

 

Iron has a lower thermal conductivity than aluminum. That means it doesn't transfer heat as well as aluminum. For a NA engine, aluminum heads typically allow you to run more compression without detonation because it helps prevent hot spots from forming in the combustion chamber. But for an extreme turbo set up, you want to dissipate that excess combustion energy in the turbine. You do not want it to dissipate through the engine components into the coolant or oil. Thus iron head and ceramic coatings (to reflect the heat back into the exhaust stream) will increase maximum overall performance by increasing the maximum theoretical Carnot efficiency.

 

It is very true that overheating the turbo means it will not live as long. But for a race engine this is a price you pay for that last ounce of HP.

[Guest Slack00]

Dammit!....don't you hate when you hit a wrong key combo and your browser moves forward and lose your whole message when you go back? Well, that's happened to me TWICE this weekend, so I'll try to be EVEN briefer this (THIRD) time...

 

Well, no. Not trying to be condescending or get into a pissing contest of any kind. Just want to see the correct information in the posts.

Agreed, all in the name of truth. In our case, I think it is an issue of semantics and imprecision that I will attempt to clear up.

 

The idea that the exhaust velocity is what moves the turbine is a common misconception. It is a somewhat confusing discussion since the exhaust is accelerated in the turbine stage as it is allowed to expand. But make no mistake, the hotter the exhaust charge, the more energy it contains and thus the more work that can be extracted from it.

Actually, no, it is the "exhaust velocity" that moves the turbine. It is a somewhat confusing discussion when you bring Thermodynamics to the table, since the heats and pressures are related. But make no mistake, the higher the pressure differential across the turbine, the more work that is done by the turbine.

 

I speak of "exhaust velocity" but a more precise term would have been "pressure differential". But it is indeed the flow from this existing pressure differential (or rather, the pressure differential that is created by the obstructions of the turbine blades) that causes work to be done.

 

A gas does work on a windmill when an obstruction of the vanes to an oncoming wind creates a pressure drop, turning the vanes, and, eventually the attached stone mill. A propeller does work on a gas when the power from the engine rotates the prop, causing a pressure spike, powering the airplane forward.

 

Now, in both these scenarios, heat may have changed, but it isn't heat that caused the propellers/vanes to turn. Honestly, the turbine is equally simple of a device.

 

Pick up a thermodynamics book and read the sections about the Carnot cycle, specifically the concept of enthalpy. This link may be a bit esoteric but it is well hyperlinked to understand the concept of a heat engine.

 

http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/heaeng.html#c1

 

Another way to think of it is it is the heat being released by the gas burning in the combustion chamber that powers the engine in the first place.

No need to...I got my degree from Texas A&M University in Mechanical Engineering, so Thermodynamics is something I am acquainted with; definitely not too esoteric for me. But if it's book explanations you want, here I have "Engines: An Intorduction" by John L. Lumley which might be able to shed some light on the subject.

 

I think we are arguing over semantics...

 

First of all, enthalpy and other associated heat terms in Thermodynamics are merely expressions of the internal energy of something. (They must not be confused with temperature, which gives us an indication of internal energy, but equivalent temperatures of various objects are not equivalent in terms of energy.) Furthermore, these terms can be traded and exchanged with others. Thermodynamics deals with heat because it is a convenient way to express many transfers of energy.

 

We may be getting hung up there. For example:

 

If I drop a rock of a cliff, one person might say, "Only gravity and change in height affect the energy" by looking at it from a potential energy standpoint. But another person will say, "Only the mass and square of velocity affect the energy" by looking at it from a kinetic energy standpoint. The two are related, and ideally, they would be the same. But in the real world, full of irreversible losses, the more accurate method would be by calculating the kinetic energy at impact. And what is actually doing the work on the rock is gravity, not "velocity".

 

With the turbine, one person might say, "Its only the change of internal energy of the gas that affects the work" by looking at it's change in enthalpy states. The another person will say, "work is a function of the pressure drop created by the turbine." This time, the change of enthalpy, which is easily measured, would be just as accurate in determining the work extracted. But what is actually doing the work is a pressure differential, not "heat".

 

Secondly, you must consider the unique property of a gas. A gas varies in pressure and/or volume when varied in amount of heat added/subtracted. A solid does not do this. Nor does a liquid. They have constant volumes and pressures. The internal combustion engine and the turbocharger were designed to take advantage of this distinct property. IT IS THE GAS THAT DOES THE WORK ON THESE MACHINES, not the heat. If I feed an engine water and then change the heat levels, it will not power it. Nor will it be powered if I feed it gravel and then add heat. But, with changes in design, I can power the internal combustion engine with other gases and fuel combinations. Natural gas/air, for instance. Or hydrogen. It is the PRESSURE ON THE PISTON HEAD that creates torque, though, not heat.

 

If I were to take the turbine and place it in a heated oven, would it do work? Of course not. No work is possible without flow. What if I straddled the turbine across a hot and cold zone? No work is done unless there is a pressure differential between the two. Whe work done is directly proportional to the amount of flow, in the form of a pressure differential!

 

Here is where I may be being more specific than you when I say "heat does nothing for a turbine." For a given volume, heat creates more pressure, and pressure creates more work. But heat does not create more work without pressure.

 

You mention the Carnot cycle, but the actual idealization of the four cycle internal combustion engine is the Otto cycle (I give you credit in that the Otto cycle is just a more specific version of the Carnot cycle, but the Carnot cycle is NOT the Otto cycle...the Otto cycle is characterized by two adiabatic changes of state). In either case, you may notice that the axes are pressure and volume. NOT HEAT.

 

From "Engines: An Introduction":

 

Section 1.1 "THE IDEAL OTTO CYCLE"

 

A cycle is an idealization of what goes on in one of the devices that thermodynamicists call heat engines: that is, a gasoline or diesel engine, a jet engine, a steam engine, and so forth. All of these take some energy source and convert some of that energy into useful work. In the spark-ignition engine the energy source is a chemical fuel, usually gasoline, which is combined with oxygen from the air by burning to release heat. Expansion of the heated gases does the mechanical work...

 

Section 1.5 "MEAN EFFECTIVE PRESSURES"

 

It is helpful to define several qualities that will call mean effective pressures. A mean effective pressure is the constant pressure, which, acting on the piston area through the stroke, would produce the observed work per cycle...

 

Section 2.14.1 "SUPERCHARGING/TURBOCHARGING"

 

As we saw in Chapter 1, one of the ways of increasing engine performance is by increasing the inlet density. This can be done by manifold tuning, as we have seen in Section 2.12.3, or by supercharging or turbocharging. Supercharging used to be the generic term for using some mechanical device for increasing the inlet density; now it is taken to refer to only positive displacement devices, and turbocharging is used to refer to dynamic devices. A dynamic device is one, like a centrifugal compressor, in which there is a direct connection between the inlet and the outlet (so that, if the device were not rotating, there would be no pressure difference), and which produces its pressure difference from the motion of winglets, or blades, through the air, produced by rotation of the device.

 

Granted, that one was on the compressor, but it's corollary can be found here, Section 2.14.4 "TURBINES"

 

For the exhaust gas turbine, the isentropic efficiency is defined as

 

nT= (actual power output)/(adiabatic reversible power output) (2.55)

 

(applied from the initial state to the same final pressure). That is, the inverse of the definition of the compressor, because the turbine produces power, instead of absorbing it. In exactly the same way as for the compressor, we can write

 

(rate of work) = (mass rate)(Cp)(nT)(T3)[1-(P4/P3)^((lambda-1)/lambda)] (2.56)

 

where 3 refers to the state at the inlet to the turbine, and 4 to the state at the exit. Enthalpy is dropping, since work is being extracted....

 

Oh, but now you say "LOOK, there's a T3 term, my inlet temperature MATTERS! SEE!" But in the previous section, 2.14.3 "THERMODYNAMICS" laid the groundwork that

 

In an isentropic process, the inlet and outlet temperatures and pressures are related by

 

T2s/T1 = (P2/P1)^((lambda-1)/lambda) (2.52)

 

Its not too hard to figure out its really the pressure differential, not the heat, that powers a turbine. But the heat and pressure are related.

 

Looks like this guy agrees with me:

 

http://van.hep.uiuc.edu/van/qa/section/States_of_Matter_and_Energy/Types_of_Energy/20020430000115.htm

 

Not hard to figure that this same effect occurs in the turbine stage of the turbo.

Actually, no. The Carnot (and Otto) cycles, are just that: cycles. The turbine stage itself undergoes no such cycle. It is merely half of that cycle, a depressurization and increase in volume. A one way trip. However, when the whole turbo is taken into consideration, it resembles the cycle....but it's still not the same. The turbo affects two seperate gas streams, the Carnot/Otto cycles assume you are using a discrete gas volume. The only thing transferred is energy from the turbine to the compressor via the shaft.

 

Here's another "heat(ed air)-is-good-for-an-engine" myth-buster: heated gas does have more energy to be harnessed...but why do we use intercoolers? Why do we "take all that good heat energy out"? Why not add heaters before the combustion phase? The answer of course, is that what we really want is gas/air density, and just by adding heat, we do not increase the density of gas/air molecules, and, therefore, do not increase combustion pressure on the piston, since combustion occurs at a static temperature. We also get dangerously close to knocking! So I ask you again, does the engine work by heat itself, or does it work by changing volumes and pressures?

 

For a variable volume, cooling increases density. For a constant volume, heating increases pressure. Enthalpy is not so much a factor as it is a descriptor.

 

Iron has a lower thermal conductivity than aluminum. That means it doesn't transfer heat as well as aluminum. For a NA engine, aluminum heads typically allow you to run more compression without detonation because it helps prevent hot spots from forming in the combustion chamber. But for an extreme turbo set up, you want to dissipate that excess combustion energy in the turbine. You do not want it to dissipate through the engine components into the coolant or oil. Thus iron head and ceramic coatings (to reflect the heat back into the exhaust stream) will increase maximum overall performance by increasing the maximum theoretical Carnot efficiency.

You want the heat back in the cylinders, not for the heat itself, but for the pressure increase it generates on that discrete volume. If you could add pressure without adding the heat, then that would be ideal. But because of the whole PV=nRT, we can't.

 

Additionally, you can only use as much heat as your turbo can handle. And I don't mean in terms of the heat resistance/conductance of the materials, I mean in the design of the vanes and the housing itself. If a turbo impeller/housing combo is only so efficient, it is not affected by changes in inlet temperatures so much. If I increase the inlet temperature, the outlet temperature may increase as well. In other words, the turbo may be only able to handle so much of a pressure drop. Meaning not much more work would have been done. This is a design issue.

 

For a NA engine, since the exhaust pressure is not being harnessed, it is desirable to keep the heat just below the what the materials can handle.

 

It is very true that overheating the turbo means it will not live as long. But for a race engine this is a price you pay for that last ounce of HP.

True dat.