Keep island turbo set up or remove it????

[91 zeee]

I have a recently purchased 81 delorean that I am going to start a semi restoration on. It has the island turbo twin turbo set up on it. My question is... Is the car more valuable/desirable with or without it?? I can't decide if I should keep it or remove it. Please let me know your thoughts. Thanks!

[Silverbullet]

Mine had the turbos when I bought it, I removed them, as I live in CA and it never would have passed smog. I did do a Stage 1 with headers and cats... It is a really reliable car now and I am happy with my decision.

[Jonathan]

I have a recently purchased 81 delorean that I am going to start a semi restoration on. It has the island turbo twin turbo set up on it. My question is... Is the car more valuable/desirable with or without it?? I can't decide if I should keep it or remove it. Please let me know your thoughts. Thanks!

If the turbo is working well and the rest of the car is reliable and in good shape, then yes, leaving the turbo on there will increase the value, desirability and rarity.

If the turbo is on there but doesn't work well or reliably, then it will have the opposite effect.

Turbo set-ups are seemingly quite rare on our cars, when you look at the fleet of 9,000 cars anyway. That will be desirable for some people out there. More so if it is working, less if it isn't.

I can't speak to the effect the turbo will/would have on performance as I have no experience with them. I will say that several other factors affect performance on our cars, so make any decisions on increasing performance based on a good condition stock car and not one that feels like a dog in part because it's not tuned/repaired correctly. The cars aren't lightning fast, but they aren't all that bad if you have everything working well.

[powerline84]

I have the single turbo BAE setup...different then what you have but after tearing my engine down and seing the blow by / terrible design I decided that I am removing my turbo setup....for what it's worth.

[David T]

I have the single turbo BAE setup...different then what you have but after tearing my engine down and seing the blow by / terrible design I decided that I am removing my turbo setup....for what it's worth.

There are two camps of opposite thought. There is the one side that thinks the turbos are an abortion and should be removed. The other believes that it makes the car more like it was going to be, with the Legend Industries turbo option. If you are going to drive the car and not worry about it's value so much the car will perform a LOT better with the turbos. Of course they MUST be tuned correctly and running well or you can do serious damage to the motor (if it hasn't already happened). If and when you decide to sell the car the question of value becomes more relevant. At that time you can decide what to do. It is possible to leave the stuff on but inactivate it. My advice would be to do some testing on the motor to make sure it is in good health first of all. If it is OK then check out the turbos. They may need to be rebuilt. If you decide to keep the turbos get the car to a shop and have it checked out and tuned up. Not too many can or will do that. PJ Grady is one of them that will. Boost pressure MUST be limited to below 6# or you will wreck the stock pistons.

[DMCMW Dave]

Both of the original aftermarket turbo kits (single and twin) are, by todays standards, horribly (non-)engineered and difficult to maintain. The turbos are obsolete and have difficult to get rebuild parts. There is essentially no engine management systems on them so they don't run much boost, and still tend to cause lots of blow-by and internal engine issues. We've removed quite a few of them. They add an insane amount of added unsupported weight to the exhaust manifold mounts which causes other issues. They make simple jobs (belt replacement for one) more complicated. And so on.

When the turbos fail you'll see raw engine oil coming out of the exhaust, the seals fail such that the oil is dumped into the "hot" side and goes right out the exhaust. Look for oil in the mufflers as you take it apart.

When they run correctly they add a reasonable bit of power, but not IMO worth the effort.

I've never seen that they added to the resale value of the car, in fact to most buyers they are a negative once they look into it. To convert back to stock you'll need a complete aftermarket exhaust system, OR a complete OEM system (brackets and all) from someone else who has already installed an aftermarket system. If you go that route be sure they sell you EVERYTHING including the bottom mounts, bushings, top mount, crossover, manifolds, converter etc. Vendors all sell a hardware kit (studs and gaskets) so don't worry about that stuff.

The best analogy I can come up with is that turbos are like a swimming pool added to a house in the northern half of the country. Valuable to the few who actually want to deal with it, a maintenance-intensive negative to most buyers.

[powerline84]

"The best analogy I can come up with is that turbos are like a swimming pool added to a house in the northern half of the country. Valuable to the few who actually want to deal with it, a maintenance-intensive negative to most buyers".[/QUOTE]

Growing up Near Buffalo this was hilarious when I read it, and spot on lol !

[FABombjoy]

When the turbos fail you'll see raw engine oil coming out of the exhaust, the seals fail such that the oil is dumped into the "hot" side and goes right out the exhaust. Look for oil in the mufflers as you take it apart.
I've not dissected a Rajay turbo, but normally this failure mode is going to be due to improper oil drain. Every BAE kit I've ever seen installed has the center section clocked wrong, and -10AN (5/8 ID) is barely adequate given the height of the turbo and draining directly against the splash shield.

Barely adequate crankcase ventilation, even for a na motor, and a direct vacuum line from boosted air into the crankcase does not help the drain situation.

I think the hard parts of the kits were OK, (BAE over Island, personally). But I agree that the controls and implementation are questionable at best.

[David T]

Both of the original aftermarket turbo kits (single and twin) are, by todays standards, horribly (non-)engineered and difficult to maintain. The turbos are obsolete and have difficult to get rebuild parts. There is essentially no engine management systems on them so they don't run much boost, and still tend to cause lots of blow-by and internal engine issues. We've removed quite a few of them. They add an insane amount of added unsupported weight to the exhaust manifold mounts which causes other issues. They make simple jobs (belt replacement for one) more complicated. And so on.

When the turbos fail you'll see raw engine oil coming out of the exhaust, the seals fail such that the oil is dumped into the "hot" side and goes right out the exhaust. Look for oil in the mufflers as you take it apart.

When they run correctly they add a reasonable bit of power, but not IMO worth the effort.

I've never seen that they added to the resale value of the car, in fact to most buyers they are a negative once they look into it. To convert back to stock you'll need a complete aftermarket exhaust system, OR a complete OEM system (brackets and all) from someone else who has already installed an aftermarket system. If you go that route be sure they sell you EVERYTHING including the bottom mounts, bushings, top mount, crossover, manifolds, converter etc. Vendors all sell a hardware kit (studs and gaskets) so don't worry about that stuff.

The best analogy I can come up with is that turbos are like a swimming pool added to a house in the northern half of the country. Valuable to the few who actually want to deal with it, a maintenance-intensive negative to most buyers.

While all of that may be true, the Island Turbo system can be made to function well. It does take extra service, it is finicky and can do severe damage to the motor. The control system, by today's standards is archaic. Back in the '80's it was not even state of the art. A major reason most owners have problems with it is because it is not taken care of or serviced by someone who knows what to do. Especially as the system ages and requires even more attention. Parts can still be obtained for service and repair. Even the turbos can be sourced if necessary but for the most part they are rebuildable. If an owner is willing to spend some money the control system can be modernized and other mods can be done like methanol injection. Drive a stock Delorean and then drive one with the Island Turbo kit (in good running condition of course!) and then tell me which one you like best. A turbo kit is the best option to add a few precious HP with a good kick to it. All of the other options, mainly engine swaps, are much more expensive and go even further from "stock". If you decide you have to remove the turbo kit I have a complete kit of parts that can return you to stock. A whole exhaust system, all of the pipes, brackets, plugs, and distributor. PM me. I would consider a swap for no money so all it will cost you is the labor to R & R and shipping.

[91 zeee]

wow.... y'all are awesome. This is just the type of info I was looking for. The only problem now is weighing the pros and cons......I assumed they would be set up and work correctly; I see now that is a bad assumption. I will look it over and check it out before making the decision.

David T.....I might be interested in purchasing or swapping for stock exhaust....will let you know.

It is still a difficult decision.........I really was expecting the consensus to be "keep the turbos.. they add value". If anything, it seems the opposite may be true....wow.....

[Brian_SS_TT]

Test the engine compression, check seal etc, and make sure boost is set to under 6. Definitley fun to drive. Turbos can be easily rebuilt by a repuatable shop for about $325-$375 each, I've had my rebuilt with very solid results. If it's all set up properly just keep an eye on things....Agree with everyones comments not ideal for tunining, arcaic design etc but takes 130hp to about 210 so....

[adam_knox]

What about a turbo on an automatic? Is that doable? Would it then have the "feel" of a 5 speed?

[Iznodmad]

What about a turbo on an automatic? Is that doable? Would it then have the "feel" of a 5 speed?

http://uploads.tapatalk-cdn.com/20161217/b8a73cf8d73e46b28d21ad89fd4acb82.jpeg

Of course a modern monster EFI twin turbo
PRV is possible in the auto slushbox. Much faster than a 5 speed too.

[adam_knox]

Of course a modern monster EFI twin turbo
PRV is possible in the auto slushbox. Much faster than a 5 speed too.

Very cool! Just out of curiosity, how/when does the turbo kick in on the automatic? Is it whenever you put the pedal to the floor? Whenever you accelerate? Does the transmission smoothly shift gears while the turbo is engaged?

[Michael]

Auto vs. Manual argument in 3...2....1....

[Iznodmad]

https://vimeo.com/196093973
Here is a short video of driving the car. Didn't go past half throttle. Boost starts to build at 1/4 throttle and keeps going up from there to a max of 5 pounds (for now). Auto trans shifts smoothly. Unfortunately the gearing is all wrong to maximize the power this engine is capable of. That's exactly why I'm having a five speed car built with intercoolers and methanol injection next!

[Domi]

http://uploads.tapatalk-cdn.com/20161217/b8a73cf8d73e46b28d21ad89fd4acb82.jpeg

Of course a modern monster EFI twin turbo
PRV is possible in the auto slushbox. Much faster than a 5 speed too.

Amazing engine compartment, it's beautiful :thumbup:

[powerline84]

Beautiful engine brother

[SS Spoiler]

Dick Ryan [raddad] removed his twin turbo setup.....

[delornut]

I've not dissected a Rajay turbo, but normally this failure mode is going to be due to improper oil drain. Every BAE kit I've ever seen installed has the center section clocked wrong, and -10AN (5/8 ID) is barely adequate given the height of the turbo and draining directly against the splash shield.

Barely adequate crankcase ventilation, even for a na motor, and a direct vacuum line from boosted air into the crankcase does not help the drain situation.

I think the hard parts of the kits were OK, (BAE over Island, personally). But I agree that the controls and implementation are questionable at best.


You're very right. Turbos of that era didn't use the water cooled ceramic bearings seen today, they floated the center shaft in oil which gets whipped into a thick viscosity which doesn't flow well. The Rajay BAE used was mounted very low and the drain line was, as you say, at a really poor angle. Oil could back up and work into the intake side. I built a custom single turbo system on my DeLorean that I ran with for several years but it was a constant struggle to keep things working right. I ended up removing it and going a different route to make the car easier to live with.

[David T]

You're very right. Turbos of that era didn't use the water cooled ceramic bearings seen today, they floated the center shaft in oil which gets whipped into a thick viscosity which doesn't flow well. The Rajay BAE used was mounted very low and the drain line was, as you say, at a really poor angle. Oil could back up and work into the intake side. I built a custom single turbo system on my DeLorean that I ran with for several years but it was a constant struggle to keep things working right. I ended up removing it and going a different route to make the car easier to live with.

The complaint that the turbo isn't optimized to the gearing of the car is correct. The timing advance also is not great. Even with all of that the car will pull like a freight train. It just shows you how much more can be obtained if you can "dial in" everything correctly. With modern engine management systems it can be done but it is a LOT of work. And you still can't do much about the gearing. With the automatic you have a bigger "fudge factor" because of the torque convertor. As for the oil, you have to go with full synthetic and there are ceramic bearing kits. The latest IHI turbos come water cooled if you want to go through the trouble of hooking that up. No matter what you do it does increase the amount of service the car requires to keep it all working. IMHO it is worth it for the fun factor!

[PJ Grady Inc.]

The Island turbo kit is worth keeping if you want more performance and don't mind some maintenance hassles in the short or long run depending on it's current condition. I do not recommend it to be mated to an automatic Delorean however as it won't stand up to the extra power for long IMHO.
Rob

[FABombjoy]

The Rajay BAE used was mounted very low and the drain line was, as you say, at a really poor angle. Oil could back up and work into the intake side.
I am very familiar with the leaking into the exhaust housing failure mode :D

Actually both intake and exhaust because my turbo builder didn't know how to properly install a carbon seal and i misted my intake with oil for a few hundred miles.

47915

I tried about a half dozen low mount turbo drain solutions. I desperately wanted to avoid using an electric scavenge pump and I finally got my wish in the form of a 3/4" drain into the side of the pan. "By the book" draining below the sump line is not supposed to work except that it actually works just fine.


Turbos of that era didn't use the water cooled ceramic bearings seen today
Ah, you don't need all that fancy stuff :) A lot of OEMs still use journal bearing turbos. My last two DDs were (Subaru WRX and Focus ST). Water cooling is definitely helpful to longevity tho!


I built a custom single turbo system on my DeLorean that I ran with for several years but it was a constant struggle to keep things working right. I ended up removing it and going a different route to make the car easier to live with.
Out of curiousity, what problems did you encounter? Feel free to PM me so as to not further derail the thread

FWIW with my T3 setup, in 4th gear boost starts at 2200 RPM with 5psi by 2600. Gets about 26mpg on the highway cruising 75-80. Response under load is satisfactory. It's not the fastest DMC by a long shot but it's just what the car needed.

[91 zeee]

The Island turbo kit is worth keeping if you want more performance and don't mind some maintenance hassles in the short or long run depending on it's current condition. I do not recommend it to be mated to an automatic Delorean however as it won't stand up to the extra power for long IMHO.
Rob

Thanks Rob. It does seem unique. Luckily I have a 5 speed. I'm leaning towards keeping it. This thread has been very helpful. I really appreciate everyone's input. What a great forum.

[Delorean Industries]

The auto transmission is only as weak as the engine management pushing on it. When I designed the system above for Darren considerable time was spent on engine map thresholds. EMT perimeters based on TPS and MAP rate of change prevent the user from shocking the transmission when in drive. This is really only noticeable on a 2/3 up shift with your foot in it but prevents harsh governor commands from allowing the engine making excessive power during shift bands. IE TPS/MAP changes dictate charge pressure control between shifts as the waste gates are solenoid controlled. When I bring the car up for a number of other updates shortly I will make a video of how this works while driving.

[David T]

The auto transmission is only as weak as the engine management pushing on it. When I designed the system above for Darren considerable time was spent on engine map thresholds. EMT perimeters based on TPS and MAP rate of change prevent the user from shocking the transmission when in drive. This is really only noticeable on a 2/3 up shift with your foot in it but prevents harsh governor commands from allowing the engine making excessive power during shift bands. IE TPS/MAP changes dictate charge pressure control between shifts as the waste gates are solenoid controlled. When I bring the car up for a number of other updates shortly I will make a video of how this works while driving.

With the right engine management you control all operating parameters including timing, fuel, shift points, etc. You can "soften" the change between gears, control the loading on the transmission, finely control the amount of boost, etc. The biggest challenge is to create a table under all conceivable operating conditions. That includes operating temperatures, fuel octane, etc. It is a BIG job. So big I don't know if any one individual or small company can accomplish it. The big manufacturers have a small army of people who tweak this stuff to get it right. Properly done it can unleash a lot of untapped potential. We see little 4 cylinder motors make over 300 HP while still meeting government standards for emissions and fuel economy.

[Delorean Industries]

Yeah it's not that complicated.... Sensor input dictated the condition set. Software is highly intuitive if you point it within a direction and constraints.

[David T]

Yeah it's not that complicated.... Sensor input dictated the condition set. Software is highly intuitive if you point it within a direction and constraints.

The software is constantly improving so it can do more and more of the "little details". I am not keeping up with the latest and greatest so I am not aware of today's state of the art but I know it is quite complicated. The more inputs and outputs you control the more complicated it gets. If you have done it successfully you deserve congratulations. It is a major accomplishment. Just getting it to work on one car though is not a true test of it's capabilities. Too limited a test but it's a start. Another major capability of a well designed engine management system is it's ability to detect and report errors and malfunctions. Can your system do that too?

[PJ Grady Inc.]

This automatic has its origins in the lowly TM 180 "Stroudsburg" transmission which utilized the same C1 drum mated to a turbine shaft. That was the transmission introduced in the 1978 Chevy Chevette...not exactly a fire breather! A stock Delorean makes enough power to commonly cause catastrophic failure soon after the computer governor starts malfunctioning which most owners know first hand is not uncommon. To say that some fancy engine management system will make this transmission endure 300 plus turbocharged horsepower is IMHO wishful thinking. I've probably rebuilt/replaced more 4141-80 transmissions than anyone alive and while I enjoy working on them I can't say it's a durable unit.
I'd like to see what Darren thinks of his turbo equipped automatic's reliability in 10K miles assuming it ever makes it that far. Good luck with that!
I'm not trying to offend....I'm just being honest with my opinion. Feel free to differ. Maybe we should get back to turbos now?
Rob

[David T]

This automatic has its origins in the lowly TM 180 "Stroudsburg" transmission which utilized the same C1 drum mated to a turbine shaft. That was the transmission introduced in the 1978 Chevy Chevette...not exactly a fire breather! A stock Delorean makes enough power to commonly cause catastrophic failure soon after the computer governor starts malfunctioning which most owners know first hand is not uncommon. To say that some fancy engine management system will make this transmission endure 300 plus turbocharged horsepower is IMHO wishful thinking. I've probably rebuilt/replaced more 4141-80 transmissions than anyone alive and while I enjoy working on them I can't say it's a durable unit.
I'd like to see what Darren thinks of his turbo equipped automatic's reliability in 10K miles assuming it ever makes it that far. Good luck with that!
I'm not trying to offend....I'm just being honest with my opinion. Feel free to differ. Maybe we should get back to turbos now?
Rob

That finely designed and built (by the French!) "slush box" is also used in a Grumman mail truck! While it does have it's weak points, a properly tuned Engine Management System can precisely limit power where it is weakest and take full advantage of the torque convertor's capabilities. Anyone utilizing turbos to increase power must understand that they are stressing the drivetrain harder which ultimately leads to early failure of the weaker parts, transmissions, pistons, etc. In aircraft adding a turbo automatically cuts the service life of a lot of the parts in HALF! Just FYI the 5 speed transmission is only supposed to handle 150 HP, Lotus got it handling 350 HP! With the right kind of engineering you CAN improve things a lot. As a rough comparison does anyone know how long a clutch lasts in a turbo car vs a non-turbo car? I would guess not as long in the turbo car. As for a bad shift computer being able to damage the auto, abrupt, sudden, and erratic shifting can't be good for ANY transmission so that is not a valid comparison. A properly designed EMS should be able to do much better than the cr-ppy "shift computer" aka governor. It really isn't much more than a badly designed voltage comparator, hardly enough there to use it and the word "computer" in the same sentence.

John Conway, one of the original designers of the Island Turbo system, recounted to me a story about how the turbo kit worked when they tried it on their first automatic. It scared him so much he thought it was going to rip the transmission right out of the car! He thought they should not try to sell the turbo kit to anyone to put into an automatic. He did admit it went like a Bat out of H-ll though! The shift computer was not modified to handle the turbo kit and the turbo kit was not modified to be installed into an automatic. A well designed EMS should be able to tame the turbos enough to get some longevity if it can also handle the shifting.

[Delorean3610]

As an owner who's car came with the island turbo setup, I haven't had any maintenance issues. They make the car a lot more fun.

[nullset]

If you decide to remove it, I'd happily sell you my stock exhaust setup.