[andre968]

Hello everyone...I am new here and I am glad this forum is here. If there is a better forum to ask this question on, please let me know.



I am determined to have a 968 Turbo. I wonder what is the most cost effective way to do this. It needs to be at least 350 rwhp on 93 octane, and probably will be 400rwhp. I have no interest in racing or beating up on the car, I just want to have enough power to be the fastest thing on the road, and be able to pull away from anyone who might be chasing me.



My first thought is to just transplant a 951 motor and use



350rwhp kit $4000 lindsay racing has one, consists of:

# Lindsey Sport Turbo

# Lindsey Stage II Mass Air Flow Kit with Fuel Control

# Lindsey Performance Computer Chips

# Siemens 55# Injectors

# Lindsey Dual Port Wastegate

# Lindsey 3" Exhaust System or Optional 4" Upgrade

# Lindsey Manual Boost Controller

# 3.0 Bar Fuel Pressue Regulator

Intercooler $400

Head $500

port match intake

Steam vent kit $40

Rod bearings $65

Main bearings $170

Belt/rollers $160

Eng rebuild kit $750

Baffle for oil pan

Studs for head, caps

Oil cooler

BOV $100

possible rods, don't know if necessary though





I feel a combo such as this would make 400 rwhp on pump gas.



My question is, is this a good idea? Maybe it would be easier to buy a 951 and change the rear bumper and taillights to 968 type, and put 968 front clip. The interior is already identical. It would have the looks I want. I don't know if it would be easy to change the front clip though. Plus it would be a mutt.



Or...what about using the 3 liter engine from the 968, and adding turbo equipment to it? I assume I would have to put new rods and pistons, as well as all the items above, plus a bunch of expensive manifolds and piping for the turbo. What about the head? Why did they use an 8 valve head on the 968 turbos when they could have used the 16 valve head? It seems to me the 16 would flow better. Would the variocam still be helpful? Would it still work even? What type of Engine management would I use? And then the transmission, of course, the 6 speed wasn't designed for turbo, and seems to go bad even without turbo, so I assume a 951 trans would be manditory.



Basically, I would like to know what is the most cost effective way to do this. I know some people have made 968 turbos, I just don't know how. It seems to me the cheapest way is to just use a 951 motorand trans. Then I could sell the 968 motor/trans and get a bunch of money for it.



I can do all work myself except possibly the tuning of the engine management system, and I can probably figure that out too. so at least I wont have a lot of labor cost.



Are there any websites I could look at to learn more about this?



Thanks a lot... I know it it a lot of questions, but perhaps some of you guys know about this and wouldn't mind answering. I have looked into a lot of different ways to get 400 or 500 rwhp, and the Porsche is my favorite idea. It can be done with a BMW 3 series for about $10,000 (plus the cost of the car), and the motors will hold 1000rwhp. I just don't like bmw's nearly as much as the Porsche. I have considered the 951, but I don't really want the 20 year old styling. When I drive my 968 cab around, people ask if it is a brand new model that they haven't seen yet. One guy just assumed it was a 2008 model. It is so rare and beautiful that people think it is new, and I have been asked if it costs $100,000. It has the proportions and handling of a supercar. I don't want to just buy a Corvette Z06. They are mean looking. I don't want a mean and nasty looking car.



thanks again... any guidance is greatly appreciated. I don't want to take this too lightly and do the wrong thing. I can't just put my trust into some guy or soupage company that I don't trust. Sometimes they just want to sell you all their products even if there are better items available elsewhere. I don't want to spend thousands on pieces that are not needed, especially if the money could better be spent elsewhere.

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[Stephenwz968]

I'm sure many will chime in here, and there is a long discussion on rennlist about this very issue, using a 951 motor vs. a 968 motor. They both have advantages and disadvantages. In a nutshell, the 3.0 16v with lowered compression via a thicker headgasket or turbo pistons could be the most cost effective way to do it; the intake manifold modification is dificult. An 8 valve conversion needs the turbo pistons and the intake manifold to be from a 951.



To use a 951 motor you need the torque tube/bellhousing from that car, and need to figure out how to make the electronics work.



Hopefully someone else with more experience will chime in here or at rennlist.



Steve

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[andre968]

I just ran across a guy who did a cab with the stock 968 3.0 block, low CR pistons, and a 2.7 Naturally Aspirated head, and most everything else seemed to be donated from 951. That seems like a very cost effective way to do it. But why use the 2.7 na head? Is it better than the 2.5 951 head? Easier to use than the 3.0 liter 16v head? There must be some reason a lot of people don't make 16v turbos. The factory even used an 8v head. I find that quite strange. I would think they would be able to overcome any problems.



Thanks

Andre

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[RS Barn]

The 2.7 head has an extra cooling jacket . You can have a 2.5 head modified like that. ^The 2.7 head also has larger intake ports and requires the 951 intake manifold to be modified.

The other issue when building a turbo is where you want the power to be. If you want 350 rwhp your power is going to be more upper mid range and up. If you want more 2500 to 5k power the factory turbo RS setup is the way to go.

Pete

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[Eric_K]

The 2.7 head is used because it bolts right up to the 3.0 block. The 2.5 head needs modifications to the water passage in order to mate to the 3 liter block. With the 2.7 head you can also just use all the 951 hardware, specifically the intake and the header. If you use the 16V head you need to custom fabricate the intake and headers, which is not cheap.



I believe the most cost effective way would be to transplant a complete 951 drivetrain, including the electronics. Then you have "known" setup where all the common 951 goodies are plug and play. Any setup using the stock 968 bottom end will be more of a one off and may not be able support enough boost to make you happy.



I have been working on my 951 engine for a long while. These being ~20 year old engines just about evrything needs to be replaced. The 'while you are in there' list can get quite long.

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[RS Barn]

The factory 968TS is really a 3.0L 951. There is a combination of some various components but 951 Head, manifolds, bell housing, sensors and electronics.

It does get touchy when mixing and matching stuff.

Pete

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[andre968]

[quote name='RS Barn' post='46342' date='Jan 25 2008, 08:57 PM']The factory 968TS is really a 3.0L 951. There is a combination of some various components but 951 Head, manifolds, bell housing, sensors and electronics.

It does get touchy when mixing and matching stuff.

Pete[/quote]





I just noticed that you are located in PA. I am rather close to you. Maybe you would be interested in helping with this project. I am trying to decide 16v or 8v, but one way or another it will be done soon. (within 6 months if possible)



I wonder if you would do this project for me, what would you charge, per job or per hour. I want to pay someone to do the short block and balancing rotating assembly, so all I have to do is bolt head on and build the rest of it. I figure if I do 16valve, I am looking at 13k+ for parts if I want to do something similar to Zoran's car in Australia. That looks nice. 500+rwhp, variocam, and I believe he has used it for some time without catastrophic failure. Although I would like to use stock DME if possible, maybe with piggybacks, as opposed to stand alone TEC 3 etc. Aren't those stand alone things expensive? I've heard of people spending $10,000 on tuning alone. Have you ever heard of anyone doing a 16v with stock computer???



On the other hand, it seems like 8v is easier because of the stock ecm, and if I used a 951 motor in it's entirety, I could sell the complete 968 motor for big $$. And I don't need 500rwhp. 400 is ok. But I would prefer not to have catastrophic failures, so I will spend whatever is necessary in the beginning to prevent that. Thanks for your help. I just started investigating this project, although I have always wanted my 968 and my turbo car to be one in the same. That makes it all affordable, when you consider you are eliminating the need for two seperate cars!



Is there any real big advantage to 3.0 8v vs. 2.5 8v?

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[333pg333]

How much money do you really have at your disposal? I mean after everything is said and done you will need more than you imagine.

You will find out more info on Rennlist re this subject but that's not a slight on this forum, just there are plenty of people who've done this already and you will find many of them there. Don't forget if you really go through with this that you'll need better suspension and brakes too. In fact you should do that first.



Erik...951 motor??? Well who'd a thunk it?

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[flash]

lol - they have seemed to gravitate over there



observation - most of the turbocharged cars the guys have over there either don't run, or at least they are constantly tinkering with them trying to get them to run right - so by default, you will find a cluster of guys with "i tried this and it didn't work", and that may help with yours by at least giving you a list of what not to do



roflmao - of course the same can be said of mine and its suspension too - maybe today i'll finally have it done

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[FRporscheman]

Andre, I'm in the exact same position as you. I want either a turbo 968 or a 951 with a 968 body. I don't think it's cost effective to put a 968 front clip on a 951. The entire front frame would have to be swapped. Therefore I've been considering options like a 2.5L swap, a 3.0L turbo, a supercharger, etc.



I spent a few months contemplating 16v or 8v. I decided I didn't want to mess with making custom manifolds and piping. It's just too convenient to ignore that if you go 8v, you can use all the 951 parts that already exist.



Plus, the big advantage of 16v is its ability to flow more air, and thus create more horsepower at higher rpm. This always got me lured. But don't get lured. If your goal is less than 500 hp then you can accomplish that with either head. Plus there are more aftermarket kits, parts, support, and knowledge available on 8v motors. On top of all that, 8v motors are known to produce better torque at low rpms, meaning a more enjoyable drive. My car is just a street car, so all I want is torque.



If you want epic power, especially for a race car, then 16v is clearly the better choice. I can live without the high horsepower numbers and unequaled efficiency of the 16v head for a little more low-end grunt.



If you are good at welding, it might be cheaper to do a 16v low boost build, becuase you could fabricate your own manifolds. I know of someone in Australia who built a 3.0L 944S2 with a stock bottom end and head. He made custom manifolds, used standalone EMS, and like 10psi boost for 400hp easily. It was cheap.





The biggest difference in a 3.0L 8v turbo and a 2.5L 8v turbo is that the 3.0L will be a lot more expensive, and it will require less boost to create the same power as a high boost 2.5L. If you swap in a 2.5L and trick it out like your parts list above, you can get your power goal, and sell your 968 motor on the side to make a lot of money back.



There's more turbo talk on rennlist because there is a 951 forum there! Any 951 forum on the net will have tons of info on 3.0L turbo builds because that's all the rage these days in the 951 world.



Sometimes I think if my cams were actually timed right and if I could actually find 93 octane gas, I wouldn't be so disappointed with my car's power.



Good luck



Oh yeah, and all real Porsches are mutts.

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[andre968]

[quote name='flash' post='46355' date='Jan 26 2008, 09:41 AM']lol - they have seemed to gravitate over there



observation - most of the turbocharged cars the guys have over there either don't run, or at least they are constantly tinkering with them trying to get them to run right - so by default, you will find a cluster of guys with "i tried this and it didn't work", and that may help with yours by at least giving you a list of what not to do



roflmao - of course the same can be said of mine and its suspension too - maybe today i'll finally have it done[/quote]





Do you think it is possible to build one of these that will be resistant to catastrophic failures, assuming the fact that I will not be abusing it or racing it, even if I keep the boost turned down enough to limit the rwhp to 400?



I don't mind tinkering, but I would prefer not to rebuild the motor several times. I guess my question is, can Porsche 4cyl engines really hold 400rwhp on pump gas when they are built correctly, or is this the type of deal where these guys just have mad money to burn and build their motor again every few months.



I know that bmw 328i engines can hold 600 rwhp without touching the bottom end, and they can be beat on for year after year, even when you start with a motor with 90k miles and continue running 10 second 1/4 miles every weekend year after year. Now, I don't want a bmw, and I don't intend to drag race or anything like that. I just assume that if a lowly bmw can hold 600rwph in a 2.8 liter 6 cyl with 7 main bearings, perhaps a porsche can hold 66% of that with 5 bearings. I know it costs twice as much to do with porsche engine, and that is too bad. But I am not going to invest $30k or more on an assumption. If this simply won't work or can't be reliable, I will put the Z06 motor in. Or the bmw motor if it isn't too long. But that is last resort. All I want to do is have the power for good acceleration. I had a Z06 and I like the power. But I don't like Corvettes. I want my porsche and I want to eat my cake too. Let them eat cake!!! I prefer small engines with huge turbochargers. I like turbo lag. It is like a drug. You have this little motor and you step on gas and a second later the car just shoots forward like a rocket. You don't hear any huge displacement v8, all you hear is this little engine and a huge amount or air being forced through it. It goes against the convention. To me, that is worth investing a decent amount of money to be able to do in a Porsche with a Porsche engine. Imagine my surprise when I found out that the bmw 328i that I mentioned above, made 996rwhp, when the guy decided to put forged rods/pistons. That is without nitrous. Just turbo. Stock bmw cams!!! And he intends to add power to that, when he changes cams. Should add 50hp. I will try my question on rennlist. I have read a lot about the projects those guys are doing. I haven't seen anything about failures or wrong choices, or reliability/lack of reliability. I have wanted a fast (insanely fast) car for many years. Now that I have the time and money, I don't want to wait any more, It seems to me that if these things can actually be built to be semi reliable, it is possible to have the performance of a modern zo6 or Zr1, for less money (than they cost new). And the car will be a German masterpiece as opposed to a production GM piece (of...). I've had lots of GM sports cars, including the fastest they have made, and they do not drive like a Porsche. They make funny noises around town, squeeks rattles,etc. At high speed, they shake, the side windows suck out. In the case of Corvette they are made out of plastic. It is just not the same. And the looks. My god. I won't even go there.



Thanks for all help I don't want to make huge mistake.



Andre

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[andre968]

[quote name='FRporscheman' post='46406' date='Jan 26 2008, 08:42 PM']If you are good at welding, it might be cheaper to do a 16v low boost build, becuase you could fabricate your own manifolds. I know of someone in Australia who built a 3.0L 944S2 with a stock bottom end and head. He made custom manifolds, used standalone EMS, and like 10psi boost for 400hp easily. It was cheap.[/quote]





Do you mean to say that he used the stock compression ratio? Or perhaps a thicker head gasket to lower it slightly? That sounds like a good idea if it works. I don't want to use anything higher than 93 octane, so lower boost would be nice. They say you can use stock exhaust manifold. Just put on a crossover pipe to mount turbo in 951 location. I seem to be leaning towards this direction. I wouldn't have to buy another engine. Wouldn't have to sell the 968 engine. Plus, I have had very high torque cars, and they are great, but, it you try to go against an exotic at high speeds, you can end up with short end of the stick.









FYI: [When the bmw guys convert non turbo 328i's into 600rwhp turbos, they don't touch the engine except to take head off and put cometic thicker gasket on, and use arp studs. Then they proceed to raise power from 165rwhp to 600. Intake, exhaust manifolds, turbo, intercooler, and alcohol injection. and tec3r. and exhaust. They do it cheap. about $10k to quadruple the power.] Maybe this type of thing can be done on Porsche. Without the 600rwhp part of it. That # is with racing fuel anyway. The point s the motors can take it. Which surprises me somewhat.

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[FRporscheman]

[quote name='andre968' post='46412' date='Jan 26 2008, 07:27 PM']Do you mean to say that he used the stock compression ratio? Or perhaps a thicker head gasket to lower it slightly? That sounds like a good idea if it works. I don't want to use anything higher than 93 octane, so lower boost would be nice. They say you can use stock exhaust manifold. Just put on a crossover pipe to mount turbo in 951 location. I seem to be leaning towards this direction. I wouldn't have to buy another engine. Wouldn't have to sell the 968 engine. Plus, I have had very high torque cars, and they are great, but, it you try to go against an exotic at high speeds, you can end up with short end of the stick.





FYI: .....They do it cheap. about $10k to quadruple the power.......[/quote]

Andre,



Yes, he kept the stock compression ratio of 10.9:1. The 16v head is amazingly engineered. The pentroof design and central spark plug makes it extremely knock-resistant. Even with good boost and high compression, on pump gas, it was running well.



All he did was use the 951 crossover to mount the turbo in the 951 location. He welded 951 header flanges to the 16v headers to make this work. Then he custom welded a 951 intake manifold and a 16v manifold together, so it would bolt to his stock head, and still have room underneath for the turbo. The standalone EMS enabled him to tune things right and dial in perfect performance, and he said that was the easiest part.



He told me his whole converion cost him like 3 or 4 grand.



But he cranked up the boost, he got greedy! He tried 14psi and blew his headgasket. I think the way he did his turbo is the perfect way for people looking for some easy power. Except I would change one thing: Add on a brand new thick cometic head gasket!



Some people say thick head gaskets ruin engine dynamics, but RUF uses them on their supercharged cars, so I think it's OK! <img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" />

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[Renalicious]

Ok so we can use a turbo on a stock 16v engine without too much trouble. The question is, is it better to use a small turbo capable of light boost to eliminate turbo lag? Something that's only capable of delivering, say, 8psi at most. Of course I'm not sure how small such a turbo would be.



I entertain the idea of putting a turbo in the car, but I don't want to deal with the huge task of switching to an 8v engine, or losing compression (and throttle response) for the sake of huge power gains. These engines were designed for high compression, low boost, so could we get away with 8 reliably? Maybe get 300HP?

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[chris]

[quote name='andre968' post='46316' date='Jan 25 2008, 03:44 AM']I have no interest in racing or beating up on the car, I just want to have enough power to be the fastest thing on the road, and be able to pull away from anyone who might be chasing me.[/quote]

Might I be so bold as to suggest that a 968 isn't the car you are looking for?



It was never meant to be a straight line killer. It's a handling machine, and it's meant to tear up the corners.



If it has to be a Porsche, then I would recommend the 951. Tons of support, experience, and success in making big power.



Best of luck to you

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[flash]

something else to think about:



you have a nice long list of parts for the engine, complete with pricing, presumably to create a budget number



what you do not have is everything else you need for that engine to put the power to the ground



the drivetrain of the 968 is only capable of handling about 350hp - they beefed up some things for the turbo rs - the chassis and suspension bushings can handle far less, and are easily taxed at very little above stock



you will need a much better clutch, stronger axles, stronger hubs, firmer suspension and chassis bushings, and last but by no means least, bigger brakes



this does not even get into anything like more tire, street legal compliance (which changes next year) etc



i would be careful and consider everything involved, before diving into what could end up being a lot more than you bargained for



yes, the car will be a lot of fun - no it won't be the fastest thing on the road

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[saxman]

[quote name='FRporscheman' post='46568' date='Jan 30 2008, 02:01 AM']Some people say thick head gaskets ruin engine dynamics, but RUF uses them on their supercharged cars, so I think it's OK! <img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" />[/quote]

You have to be VERY careful when running a thicker headgasket. It can change the quench area of the head, resulting in significant drops in efficiency, along with increased risk of detonation.



Does this mean that all thicker head gaskets will cause this problem? No...



But do you know what the acceptable size difference is off hand? I sure don't, and I'm sure that's not a super cheap thing to figure out, and it's certainly not a cheap thing to get wrong.

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[FRporscheman]

I'm no motor master but I think ruining the squish is losing a benefit, not gaining a detriment. The engine is already so resistant to detonation that a little less resistance to detonation isn't too big of a problem overall. Of course a 6mm headgasket might bring issues but I know of one engine that used a 3.2mm gasket and stock pistons and stock-length rods... and he had a very trick engine, with no issues to speak of. High boost. He probably took his time tuning it right but it got tuned right.



Bob, some very good points. When budgeting for the engine, also budget for (at least basic) chassis mods like better tires, shocks, and pads, at the minimum.



Ren, I think what your talking about is a great idea and one I'm interested in too. It would be basically the same as that guy in Australia and his 944S2 turbo. He geared the conversion towards higher power potential so he could play with it... and when he did play with it, it blew. He's now rebuilding it as a full-on turbo motor. But for the average power-hungry 968 owner, I think his setup with a smaller turbo and a boost range of 5-8 psi would bump the power up to 300hp at the crank easily. And as long as the boost doesn't go over 8 or 10 psi, the stock-thickness head gasket will work. If your head gasket is old, higher boost levels may expedite its death so maybe stick with something lower.



The turbo you choose can't be too small. The 968 engine breathes very well and all that exhaust output will cause a small turbo to spin too fast and eventually burn up. A k26/8 or equivalent would be a good starting point.



There are other things to consider with a turbo converted car, like variocam. Variocam is awesome when off boost (like all our 968s are 100% of the time <img src="/forum/images/smilies/968/tongue.gif" class="smilie" alt="" /> ) but when on boost, it could upset the behavior of boost. One could simply unplug the variocam wire and call it a day.



And dual resonance. It probably goes straight out the window with a forced air flow, but I don't know I'm just guessing on this one.



If one does the work oneself, I think a 8psi turbo can be done cheaper than a supercharger kit. But a SC kit will be easier hands down, and removable.

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[Cloud9...68]

[quote name='FRporscheman' post='46639' date='Jan 31 2008, 02:04 AM']If one does the work oneself, I think a 8psi turbo can be done cheaper than a supercharger kit. But a SC kit will be easier hands down, and removable.[/quote]

But don't forget, with a SC, you lose your A/C, so unless you live in Vermont, that's probably a very bad idea...

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[RS Barn]

I'm sorry I haven't been able to follow this thread or post.

My Mother passed away Wednesday and I am arranging Funeral.

I need to look at information posted and digest to make comments.

Pete

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