BoostedBalls

Just go with the 5th injector, I've been running mine for a long time and it works great and is way simple. maybe use two maller ones and stage them closely. I'm about to instal a 6th injector to come on at 19-23 psi. My single injector has kept my engine together at 19psi and I'm running 14.20 seconds in the 1/4 pretty consistantly. Same with my gl-10 last year, it had 200k on the engine.

I have a spider intake from a turbo car with light gray injectors and a normal turbo intake with red injectors. Is there any difference? The spider intake is missing one, I wonder if I can mismatch them.

Thermal efficiency or thermal ratio? Your cylinder pressure will be higher with higher a compression ratio regardless of exhaust temperature. Thermal efficiency is a braud term. It is normally used in the context of power output compared to heat generated when discussing internal combustion engines, thermal efficiency you described is normally used in driven pumps where intake air to exhaust air ratio is important. This is a variable in total pressure density. This variable is more important to focus on regarding turbo compressor discharge. Exhaust gas temperature in a natually aspirated engine is outweighed by the importance of intake air temp and cylinder compression temp.

Are the spider intakes different for turbo and non? How about the throttlebody?

OOPS, didn't see the part about you wanting to run it NA. Yeah, 11:1 should be ok on 92 octane but again, don't bog the engine. I wouldn't run the turbo cams on it, it'll run like crap. You need more overlap. At least go with the fuel injected non-turbo cams. And a grind would help wake that puppy up too. Good luck.

The lower compression in the turbo engine would allow higher boost levels for more power potential but the higher compression ratio would make it a little more drivable and possibly better on gas. Less residual gases left in chamber after exhaust stroke. The higher compression would increase volumetric efficiency, not thermal efficiency. Thermal efficiency would actually get worse, compression is the start of heat in an internal combustion engine. Turbo street bikes can get away with 12:1 compression on 92 octane for up to around 5psi but need water inection. They have a much better burning combustion chamber than we have and they have more RPM, RPM is safety when you are riding the knock limit of your head and fuel combo. Ever notice that head gaskets like to go at WOT at low RPM? I have run 25psi a few times with no engine damage on my ea82T with low compression, try that with the higher CR and KABLAM! I know a couple guys running 15psi in Acura engines but they also have an 8,000 RPM redline, and better burning heads. The high compression will work; just remember, don't bog the engine!

The RX is an insurance total in WA and a HUGE pain to get titled/registered. The car is totally streetable and I would love to get it registered so I can do road tuning and save on gas. I've been driving an Astro van to work, blah... I'll put a glasspack on it, right now it just has an open 2.5" section of pipe that goes almost to the transmission crossmember. She's a bit noisy. I'm so tempted to do a VIN switcharoo just so I can drive it on the street. The parking brake light was on but I just didn't notice. I felt the car dragging a little bit when I was getting staged but I thought it was the locked diff in the rear.

Yep, I got her out on the strip again last night. I did runs in low range and high range. Low range redlines in 5th at the finish line but I noticed it's a lot harder to hit the gears without grinding the teeth off. High range was a lot easier to shift but I just shift into 5th at the finish line. I get past the 60' mark in less than 2 seconds in hi or low, as long as the diff is locked. The best I seem to be able to squeeze outta her is 14.20 seconds at 93mph. My 1/8 mile time was 9 seconds flat. It wasn't enough to take the WRX running bolt-on goodies, he ran a 13.4. But that new Cobra stayed right next to me until 3/4 of the way down the track. That was a blast! Now it's time to install the parts I have laying around in the garage: spider intake, T3 turbo, bigger home-built intercooler, external wastegate, Crane cams ignition, then get a pair of cams ground at Delta, MegaSquirt and possibly NOS. It was running pretty consistant in the low 14 range except for the times I grinded gears, oh, and the time I had the parking brake lighly set. DOH! It's hard to tell the difference rolling up to the line with parking brake set and the rear diff locked. I didn't notice the "parking brake" light until after the race. Oh well, it did good and everything still seems to beholding together. I got about 8 passes and still drove it onto the trailor at the end of the night.

The piss that comes out of the gas station pumps has a shelf life of 2 weeks. After that, it's quality fades rapidly. After about 9 months it's hardly flamable and begins to coagulate into a nice jelly that likes to plug fuel injectors and fuel filters. This is a real problem with MPFI because if one injector partially clogs, the others try to pick up it's slack and that cylinder runs lean until damage occurs. This is why SPFI usually outlasts MPFI, at the cost of power and efficiency of course. Old gas also effects the intake valves- The valve opens exposing the stem to the incomming jelly-spray. It of course sticks to the stem and gets dragged into the valve guide when the valve closes. After it does this a few thousand times, the jelly grabs the valve and doesn't allow it to close. This is real bad for most engines because the piston will slam into the valve, not that big of an issue with our little boxers though, just a hassle. I would dump a couple cans of chimical B12 into the fuel tank and maybe dilute with a couple cans of fresh 92 octane. The octane of the the stuff from January will not give you much performance. I would drain it but then it's hard to despose of. I would also check that the intake valve closes right before the TDC mark lines up and make sure the marks on the cams still line up. Then make sure the dist is pointing to the #1 cyl. Then it should fire. Remember FAST: F- fuel, you have crappy fuel but it should still start, filter clogged? A- air S- Spark T- timing, that's cam and ignition. If you start with new plugs it will give you a good indication of injector performance. The plugs should look all the same after a few minutes of idleing. If one is a lot lighter than the rest- you have a clogged injector. You can clean them while they are still installed in the engine. Remove the hose right at the injector and blow out the gas, then shoot some carb cleaner in the cavity and put the hose back on to keep from evaporating. Wait a few hours before starting her up.

I am about ready to start my spider swap, I plan on using the stock turbo downdraft throttlebody mounted horizontaly on the spider intake. I'm sure I'll have to make an adaptor but that might be easier than messing with throttle cables, good excuse to use the plasma cutter too. Is there a inside bore difference in the spider unit and the downdraft one?

I would change the oil and maybe put some 40W in it to slow the intake seal leakage/ ring blow-by; and dump a couple cans of B12 in the tank when it's about empty. Then run some fresh gas through it and test again. Good luck!

My 86 computer won't work for you, they changed the MAF sensor for the 1987 year and added a third connection to the unit. Oh well, hopefully someone here can give you a good deal on a working unit. My 87 unit will be up for sale soon as I get the MegaSquirt up and working, but probably not in time for you. Good luck!

This thread infuriates me almost to the point of making a long distance call to your 'mechanic'. You should NOT have agreed to pay for the 02 sensor, that was their diagnosis, not yours. This is an incompetent shop, did you check the fair business beauro first??? I would make a complaint to them. I have a computer from a 1986 turbo car, might work with your car, this group would know. $75 plus shipping. It's very easy to replace yourself. Are you familiar with electrical, oil, coolant, gear oil, etc odors? I would do a close visual inspection to see what these yahoos did to your car. Then maybe threaten lawsuit if they don't give your money back. ANYTIME a shop replaces parts on your car- make a note on the agreement to 'keep old parts'. This will get you out of paying for stuff they never replaced, very common problem. Worked for me a couple times. The shops shortcut troubleshooting by shotgunning all related parts at your expense. This group is very helpfull and will at the veary least, give you good info on exactly what you need to have done. I hope it all works out for you and let me know if you end up needing my computer.

Interesting idea, I have a similar circuit that is much larger that I am planning on using to build an electric go cart for my little boy. It will use a 12v marine battery and chevy truck starter. The potentiometer will be hooked up to the 'gas' peddal. It should work for injectors, but if you wanted to use regular peak and hold injectors- why not just build a circuit that activates at 12 psi or so that uses the stock injectors to trigger 4 separate power transistors which power 4 secondary injectors? The car would drive like normal until you hit 12psi and the computer instantly drives 2 injectors at each intake port. The ECM would reduce the pulsewidth because it would go rich for an instant, then as boost increases even more- pulsewidth would increase again. But why not just go MegaSquirt??? I'm gearing up for it soon. I just need to find out how to feed boost pressures over 20psi with it. I'm hoping ODDCOMP will give me a hand. He's already running MS. -Chuck-

The 5th injector isn't a peak-and-hold type like your other 4. It would not respond quickly enough for it to be effective in that setup. The 5th injector comes on with 12vdc and stays on, it makes a nice mist of fuel too. You can stage a few of them to come on in 3 or 4psi increments with 3 different pressure switches. It's not the greatest way to control the A/F but I would bet it works better than a carb. I'll be setting up at least one more injector on mine when I decide to turn the boost over 20. I gotta have the H2O/alky injection first.

Yes! Methanol is the ticket. I want to setup methanol/H20 @ 50/50 to come on in stages from 15, 20 and 25psi. I think 25psi should be like pulling the pin from a grenade!

I'm glad to be an inspiration, or was that perspiration? I'm happy with either! I didn't use a wide band, my budget for this car wouldn't allow it. Other projects are draining my wallet. I just used a stock sensor and autometer A/F gauge. Very sloppy readings I know, but I could see when the gauge went and stayed lean, That was 16-19 psi somewhere; boost comes on pretty fast and it's hard to tell if the needle on my boost gauge is responding quickly enough. I had an adjustable pressure switch in the console that I used to adjust the 5th injector beetween speed blasts. I got the best reading and response with the switch set at 12psi. Less than that made it bog a little. I was running an open down pipe so it may be different on a full exhaust system. The whole time I was running this setup I was assuming that I was doing serious damage but I liked the power and the car was cheap. No thrills better than cheap thrills right? Well, I opened the engine up for a rebuild last winter and found the cylinder walls to be in awesome condition. I should have just pulled the heads and freshened them up. This was on an engine with about 200k on it! * I have patterns for building a large water-to-air intercooler for these cars. I have built one already and I'll post photos of it after installation. I'll hook up some thermocouples to monitor inlet and outlet temps too! Yeah baby!

I'm the guy with the "interesting way to add more fuel under boost". The 3 angle valve job is VERY important and often overlooked. The most flow through the valves actually happens at LOW lift for a very short time. The 3 angle, if done properly, increases this flow at low lift. This makes torque. Don't be sold on a 5 angle valve job unless you plan on freshening up the heads after every other race. The 3 angle gives great performance with good longevity.

The link was dead for me but if this is the RC Engineering in Lake Havasu, AZ- they are a bunch of idiots. I worked in another shop in Lake Havasu and we got a lot of their pissed-off customers who wanted us to fix their mistakes. Just a little heads up, if it's the Lake Havasu shop I would steer clear.

You might consider moving your intercooler over to the driver side of the engine compartment. It will have a ton of heat soak in its present location. Also, moving the intercooler to the other side might allow you to use less sharp bends in the piping. Check out some cheap conduit that has nice gradual bends and maybe use some rubber hose to tie it all together. The air moving through the tubes is really dense and moving very fast. If your hood scoop is really small, you can install a radiator cooling fan from a street bike to pull air down through it. And- I used a water spray on my thunderbird setup last year and it worked awesome, it was cheap also. You can take some 5/16 fuel line and cut 1/8" piece with a razor blade to use as your gasket at the base of the injector. Seals perfectly and once again- cheap. Keep up the good work! I didnt have my camera with me down there, and am back at school now, so this is the best i can do. Put a brass Tee in right after the fuel filter and ran a high pressure line with a banjo fitting at the end to the injector's top. Ground a flat spot in the saab intake pipe, and stuck the injector there for now. Im going to fab up a new pipe with better positioning in the near future. My manual boost controller and the pressure switch are over on the left side, but its pretty straight forward to install that. just put a Y in one of the pressuresed lines and stick the switch on, cap the other end of the switch. To set it, we power braked it to get boost up and used an Ohm meter to see when the switch tripped. Banjo fitting (i didnt know what they were called so heres a pic of one...) you'll need it if you use the same Saab one i did. pic from http://www.paragonperformance.com/Images/10mm%20Banjo%20Straight2.gif if putting the link makes using that pic legal then there it is -Matt

If you are using the stock fuel cut-off pressure switch to drive the injector, no problem, if you are using a micro switch, you will need a relay. The injector doesn't pull much current but it's better to be safe. I put an LED on the dash that is wired to the injector so you can see when power is actually at the injector. My LED was kinda small to see going 90mph when you don't want to look down. I'll be installing a bigger one soon. 220 degreeze Jeeze! That's hot. That would explain why my intercooler heats the water up so fast. I was running 19psi last year on my GL-10 and 16psi this year on my RX. Now that I know the engine will hold up, I'll turn it up to 19psi again.

I have a compressor map of the stock turbo somewhere, I'll see if I can find it. Yes, the 15psi on the 1.8L is getting a little out of the prime efficiency range and I'm sure it's blowing a lot of hot air. My T3 setup last year wasn't really that much more 'grunt' than the stocker. I'll be using a dual thermocouple with data logging for my new water-to-air intercooler setup with boost gauge on the entry and exit to calculate intercooler efficiency. This should give great baseline data for a stock engine running high boost on stock turbo. My mph in the 1/4 is probably due to the loss of power at the end of the track. I have a heat exchanger that I'll be using in the front of the car to cool the intercooler water before it returns to the tank,like a Syclone/Typhoon. The setup is just pump-cooler-tank right now. Hey, I got it all thrown together right before the race. I had no idea that a gallon of icewater would get so warm in just a few seconds.

This band-aid works VERY well and by the looks of the inside of the 200k engine I used it on last year, it seems to keep things in check too. This lets the car run normally on the stock injectors for daily driving then adds a little extra juice when the foot gets heavy. Of course I do my own fabbing of parts and I get most everything from the JY, I have less than $500 into my whole car, including the car! Show me a stand alone system that can beat/ or match that. The Saab injector is a little bit bigger (flow) than the ones from the VW engines, and 9 psi is way early to trigger it. My testing showed that 15psi is where the stock fuel system starts getting overworked. I have my injector come on at 12 PSI because the needle on the boost gauge swings really quick and I think it to be safe to have a little head start on it. My RX did have two pressure switches on the passenger wheel well, I hear from most people that the fuel cut-off switch went away in 87, I juess I have an early 87 or something, weird. I have a video of that 14.3 run and it's about 5.5M in size if anyone is interested in seeing it. My ignition cut out towards the end of the track after my intercooler water supply got hot. I don't know how to post a video on the net yet. Give me your address and and I'll send it to ya.

Cool, I'll look into it.

I'm needing a clutch really badly, should I go with the XT6 flywheel or just get mine drilled in the back? I'll get the XT6 pressure plate or if anyone knows of a good aftermarket one. I don't mind being on the vurge of a hernia when I push the peddle in, I just want it to hook up when I side-step the clutch. The clutch is killing my 1/4 mile times and I might as well run a lighter flywheel while I'm at it. Maybe just stick with the heavy flywheel to help the car off the line? Hmmm????