verge Posted October 25, 2005 Share Posted October 25, 2005 Hi Y'all, You guys ROCK! I have definitely found a new home. My story: Three years ago I bought a GL 3 door 5spd at an auction for $30.:cool: The doors were locked and windows were filthy on the inside so nobody could see that it had 12,470 actual miles. For $30 bucks, what the heck! This would be my first Subaru and I have really loved their innovative cars/trucks. Well, sitting around did a number on the hood, rear seat tops and fuel tank. The original tires have dry rotted from not being on the road since the early 90's. The only gauge that worked was the speedo the rest were frozen. I bought a donor car for $100 which has provided most of the parts I needed for the project. After some minor wrench turning, it is running decent with no smoking or leaks. All the gauges have been fixed or replaced. Where I am: I put on new plug wires, changed the oil/filter, new air filter. The SPFI is real slow to build RPM. I think Maybe the TPS needs cleaning but don't know for sure. Where I want to be: I would love to terrorize some of the local dirt roads so I bought a turbo from an '87. I have the air box, intake runners/tubes, waste gate actuator and the exhaust pipes. I'm planning on gutting the cats, installing an import style (at least 8" outlet pipe ) muffler. I wanna get a K&N cone filter but will have to see if I can get the turbo working. I haven't found much info on the SPFI to TURBO conversion. Any suggestions and pictures would be greatly appreciated. Will the stock pistons be too much compression for the turbo? Anyone install an intercooler? Keeping the engine stock, can I get 150 hp out it and knock down 30+ mpg on the highway? Jackie aka Verge Quote Link to comment Share on other sites More sharing options...
subyrally Posted October 25, 2005 Share Posted October 25, 2005 hmmm, kinda lofty goals, but it can be done. stick around here and read everything you can. youll get it figured out id like to see what you can come up with too. good luck and keep us updated. Quote Link to comment Share on other sites More sharing options...
lastchance Posted October 25, 2005 Share Posted October 25, 2005 x10000000000 Will the stock pistons be too much compression for the turbo? ^You lost me there Quote Link to comment Share on other sites More sharing options...
Snowman Posted October 25, 2005 Share Posted October 25, 2005 From what I have read, you'll need to swap over to turbo heads, intake manifold, and fuel/spark management to really get much out of it. The SPFI system can handle some boost, but only a few PSI, before it can't keep up with the fuel requirements. Several people on the board have run turbo heads on carbed or SPFI blocks with good results. I think an intercooler would be a necessity for running SPFI pistons, since they're the highest compression ones offered in this engine. Quote Link to comment Share on other sites More sharing options...
verge Posted October 25, 2005 Author Share Posted October 25, 2005 I have an 88 Thunderbird Turbocoupe and have upped the boost from 10psi to 18psi. The biggest problem is that the engine starts to starve for fuel. You can add higher flow injectors or you can increase the fuel pressure via an adjustable fuel pressure regulator. If I add an adjustible fuel pressure regulator can I get around the SPFI shortcomings? With the SPFI heads what would be the max boost I could expect to achieve? Quote Link to comment Share on other sites More sharing options...
lastchance Posted October 25, 2005 Share Posted October 25, 2005 Well...When you add a RRFPR you better get bigger injectors, because what would be the point of more fuel if you don't have injectors big enough to get that fuel in the compression chamber in a consistant and constant manner? Also, just adding a RRFPR is NOT going to do much good if you don't have the spark and timing to compensate for the added fuel. My advice on the T-Bird... First: Turn the boost down or detonation is going to kill your motor. Second: Find a T-Bird or Ford message board to post questions about it. Third: When you blow the motor up on the T-Bird, install the intercooler on your boosted Subaru. With the SPFI heads what would be the max boost I could expect to achieve? ^Clarify this...Do you want consistancy and drivability or speed and sketchiness? You can boost that motor to 2 bar but, it won't last long! Stock boost on an ea81t or ea82t is ~8 lbs, so you can use that as a starting point. Quote Link to comment Share on other sites More sharing options...
verge Posted October 25, 2005 Author Share Posted October 25, 2005 I don't have any probs with the Tbird. I was just using it for reference. When the injector opens, fuel at a higher pressure will flow more giving the same effect of a bigger injector at a lower pressure. My goal is 30+ mpg and 150 hp. Don't care about the idle or if the ac works. Just wanna have some fun with it. I think 8 psi on the stock turbo should be close. If I can't get it to work, I'll have to put the car on the bottle. Has anyone on here successfully Turbo'd the SPFI using the base motor/heads? Quote Link to comment Share on other sites More sharing options...
lastchance Posted October 26, 2005 Share Posted October 26, 2005 When the injector opens, fuel at a higher pressure will flow more giving the same effect of a bigger injector at a lower pressure. Injectors don't "open" buddy...They pulse. Trying to send more fuel through an injector that is set to only pulse say 425cc is going to be limited by just that, 425cc. In newer cars, it's all about pressure and pulse duration, not sheer volume. Forcing more fuel through your fuel system to only be held up at your injectors is like building a dam on a river. Has anyone on here successfully Turbo'd the SPFI using the base motor/heads? Yes, but if you boost the stock block and heads, what are you going to do for fuel and spark management? Why not just find an ea82t to put in your SPFI car? I think this would be the EASIEST way. Quote Link to comment Share on other sites More sharing options...
Snowman Posted October 26, 2005 Share Posted October 26, 2005 Yes, the stock SPFI system has been turboed, but only with a few psi. The SPFI heads do not limit the pressure you could run, they limit flow severely. The SPFI/carb heads use one port for both cylinders, while the turbo/mpfi heads use two. I doubt you could get 150 hp without at least changing over to turbo heads and fuel management, or just swapping in an EA82T engine. The stock EA82T is 115 hp, and it breathes significantly better than a turboed SPFI engine would. If you want power and reliability, I'd swap in an EJ22 from a Legacy. 140hp stock. Quote Link to comment Share on other sites More sharing options...
Steveman09 Posted October 26, 2005 Share Posted October 26, 2005 Injectors don't "open" buddy...They pulse. Trying to send more fuel through an injector that is set to only pulse say 425cc is going to be limited by just that, 425cc. In newer cars, it's all about pressure and pulse duration, not sheer volume. Forcing more fuel through your fuel system to only be held up at your injectors is like building a dam on a river. Yes, but if you boost the stock block and heads, what are you going to do for fuel and spark management? Why not just find an ea82t to put in your SPFI car? I think this would be the EASIEST way. You are 50% right about the injector and RRFPR : You CAN raise the fuel pressure to a POINT where you can sqeeze some extra CC out of the stock injectors until you reach the point where the line pressure exceeds the injector opening pressure, then its all down hill from there and you start to LOOSE fuel efficency and lean out (bad) The Stock Fuel Injectors Last time I checked on the forums are 185CC Units, and they are capable of supporting 148HP (crank) at 100% Duty Cycle, and since running them at that rate is not safe and will lead to injector failure they can only in reality support 118HP (crank) at 80% Duty Cycle which is the safe limit, sure others on here have rolled the dice and ran the injectors at 90% maybe even 100% and had good results but you much understand they are ticking timebombs at 85%+ Duty Cycle. Sure there have been people on stock injectors putting down crazy HP numbers, but this is because they ran lean, and everyone knows lean = power to a point but more importantly = engine early death. Best power is achived around 13-13.5:1 AFR but Engine Safety would be in the 12-12.5:1 Zone and Stock Injectors with Boost turned up simply cant do this. The only thing you can do on these EA82 cars is to do the 5th Injector Setup if your looking to make more reliable power. There has been lots of success with this setup and it seems to work well, do a search on it. Good luck. Quote Link to comment Share on other sites More sharing options...
lastchance Posted October 26, 2005 Share Posted October 26, 2005 You are 50% right about the injector and RRFPR : You CAN raise the fuel pressure to a POINT where you can sqeeze some extra CC out of the stock injectors until you reach the point where the line pressure exceeds the injector opening pressure, then its all down hill from there and you start to LOOSE fuel efficency and lean out (bad) The Stock Fuel Injectors Last time I checked on the forums are 185CC Units, and they are capable of supporting 148HP (crank) at 100% Duty Cycle, and since running them at that rate is not safe and will lead to injector failure they can only in reality support 118HP (crank) at 80% Duty Cycle which is the safe limit, sure others on here have rolled the dice and ran the injectors at 90% maybe even 100% and had good results but you much understand they are ticking timebombs at 85%+ Duty Cycle. Sure there have been people on stock injectors putting down crazy HP numbers, but this is because they ran lean, and everyone knows lean = power to a point but more importantly = engine early death. Best power is achived around 13-13.5:1 AFR but Engine Safety would be in the 12-12.5:1 Zone and Stock Injectors with Boost turned up simply cant do this. The only thing you can do on these EA82 cars is to do the 5th Injector Setup if your looking to make more reliable power. There has been lots of success with this setup and it seems to work well, do a search on it. ^For sure, I was using "425cc" as an example, I didn't mean it to sound like I was specifically saying ea82t's are 425cc! Leaning out and detonating the motor is something I mentioned earlier that is a HUGE factor in cracking blocks, blowing HG's, etc... Rallitek has a 5th injector for their stock ej25/ej22 bolt on turbo kits which is actually a pretty cool deal, if you are looking at that sort of thing, I'd check out their website to see how that set up looks. 100% duty cycle...That is WAY harder then your fuel system/injectors should EVER have to work, which obviously leads us to what was mentioned above with bigger injectors, hotter spark and adjustments in engine timing to get you to the level (basically less than 80% duty cycle) you need/want WITHOUT having to sacrifice the longevity of your fuel system (fuel pump, injectors, etc) Bolt in a ej22...They are dime-a-dozen and like Snowman said 140hp stock! Quote Link to comment Share on other sites More sharing options...
verge Posted October 28, 2005 Author Share Posted October 28, 2005 My goal was: Keeping the engine stock, can I get 150 hp out it and knock down 30+ mpg on the highway? I read the posts about EA82T fuel mileage where the majority of posters get between 22 and 26 mpg - most with a stock setup. Since I would have to "find" another 35hp over stock, I'm sure that the MPG numbers would drop even further. I really liked the idea that the car is light weight and only has 12500 miles on it. I can't imagine replacing an engine that is practically brand new. Somewhere, I am missing something: My 88 Tbird weighs over 3400 pounds, is pushing over 250 hp at 18psi and can get 30 mpg on the highway. How is it that a MUCH lighter car with .5 liters less displacement and 135 less horsepower can only muster mid 20s for mpg. I'm not slamming Subaru, I just wanted a fun daily driver that would be a blast on the dirt roads. I had a 127hp Mercury Tracer LTS with a close ratio 5 speed & 4 wheel discs, the car was awesome on dirt/gravel roads! I was hoping to build an even better car without breaking the bank. Anyone interested in an SPFI 87 GL 2wd 5sp with 12500 miles. Make offer! Quote Link to comment Share on other sites More sharing options...
Snowman Posted October 28, 2005 Share Posted October 28, 2005 The 4wd really does make a substantial difference in fuel economy, especially as the car gets older and there's more parasitic drag in bearings and U-joints. Quote Link to comment Share on other sites More sharing options...
kingbobdole Posted October 28, 2005 Share Posted October 28, 2005 I posted about this in the retro fit thread. I'm planning to turbo my spfi, but I only wanna go a bit more power... the big tires kill its highwayableness. I think you guys are also kinda confused(some of you) the SPFI only has 1 big injector..... not injectors. adding a 5th injector would really be adding a second injector:drunk: Anyway I've been talking to the guy who did it to an EA81 and the hardest thing he had issues with was fuel. ... I'm a mile high and plan to intercool so I'll have less issues. Quote Link to comment Share on other sites More sharing options...
sregor13 Posted October 28, 2005 Share Posted October 28, 2005 All this technical info is making my head spin. All i can say is either put in EA82T or a EJ22. That simple. I dont know what kind of Gas mIleage you will get but you will save hundreds on bypassing all the complications of trying to convert yours over to Turbo. Quote Link to comment Share on other sites More sharing options...
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