Just thought I would let the cat out of the bag, Mavman is almost finished with the turbo project on his 75 Mav. Using a Ford powerstroke turbo and fabricating all the other items, it is really going to be a nice project for others to do. Will post pics later and give details of each segment when available. Took for a test run with just bare necessities and believe me the near stock 302 with RPM manifold and Erson cam, Holley 650, blew the tires off at 6lbs of boost. Should be fun car to drive, if he lets me???
I like the turbo too....but dont like how it fits in the tiny engine bay. There simply is no room for just flipping some shorty headers and running the pipes to the turbo. I had to use one shorty header on the pass. side, run a crossover pipe to the back of a custom manifold on the driver's side, then from the manifold to the turbo. And that doesnt count the downpipe, it will have to be built too, along with a complete exhaust system. Just from what I've driven of it, with no other tuning, it feels pretty stout. It started showing some boost at around 2500, then around 3500, full 6lbs, lots of piston smoke (from those cheap cast pistons) from the exhaust, and lots of tire smoke. She was a bit lean judging from the backfiring from the exhaust, and 2 burned plugs. I got it to 6 lbs, then the motor started making weird sounds, so I backed out of it. Honestly, I've never experienced a 302 with that much torque, and that's with NO tuning! I'm sold on turbochargers....the power is amazing, and it comes on very, very quickly. Not to mention the awesome sound it makes when spooling up, sounds a bit like one of those huge 18-wheeler diesels. Well, there's a lot more work to do before I can track test it, but hopefully we can get some pics.
Just an idea, but how about someone use their 250 or 200 straight six, then build a turbo system for it. I imagine it make around 300 HP max, but the torque down low would be amazing. Use a T-03 turbo from a standard-trans thunderbird turbo coupe, it's a perfect match for a 250, max rpm 5000. For 200's use one from a automatic-trans thunderbird tc. The standard trans cars used a .63 A/R turbine, and the autos used a .48 http://www.toohighpsi.com some interesting stuff on that site, and that guy really knows his turbos!
I like that idea and maybe one day ill go that route. I test drove a Subaru WRX on a track and drove an Audi TT and I love turbos!
If I ever have spare money, I would put a Kenny Bell blower on my EFI comet.( Full) boost at 2000 rpm at what ever boost level it is pullied for. Its crazy to do this on a Comet as there is no way in hell to ever get enough traction. Tip the toe-burn the tires. I have a unit already but it is slated for another car. But you never know, I might change my mind.
....I bet you could get it to hook up!!! all you need is a set of Mickey Thompson ET Street slicks......it's a street legal slick.....you'd really surprise those chevy guys when you pop a wheelie leaving the stop light!!!!!
Turbo sounds cool. A TO4 hair dryer ran past my mind too. However I not really keen on changing pulgs as the way the car is now. I cant imagine what it would be like to change it on a turbo car with all the sewer piping. I kind changed my mind after looking at all the nightmares on some of these import cars. I have one answer now... Vortech or Procharger for a carbed motor... hum wonder if the wife will let me get it...
Update: On the way to work yesterday morning, I climbed the bridge near our house, turbo started to spool a little, no problem. After topping the bridge, I let off to coast the rest of the way to work, and the motor died. Got to work, wouldnt start...it was locked. Diagnosis: # 6 and #7 piston broken, and # 6 cylinder wall cracked. Time for another motor. I havent run the thing hard engough to cause anything, no pinging, no detonation, heck it hasn't been over 4500 rpm yet. I think the crack was already there, and the extra power the turbo provided caused enough cylinder pressure to finish it off. I will say that the cast pistons wont take 12 lbs boost for sure, especially with no intercooler and waaaaay lean jetting. Oh and as far as changing plugs, it's easier than with the 88-300 long tube headers. Also, I had the heads off in less than an hour. Turbo is still hanging on the downpipe and driver's side manifold. I got heartbroken and left it as it was when I found the problem. I will have her going soon though....just need pistons and a camshaft for the other block and it'll be ready for some abuse. Major bummer.
Do you have a pyrometer hooked up? My 93 Ford diesel has a Banks Sidewinder turbo,and Banks doesn't want the exhaust temps over 1100 deg F. After that the pistion start to get "soft". And that is with Fordged pistons. I have managed 13 psi of boost and around 1000 deg egt. And this is a motor with 21.5 comp.ratio. Russ
If you still had the old pistons in that motor, that was the down fall. They are known for breaking just running stock after they get old. The skirts break, the rod flops around in the bore and breaks the block. You need at minimum ,hypereutic pistons and preferably forged ones with good head gaskets. Chaulk this up to learning. Can't take an old motor and expect it to live under pressure.
Well, I knew that it was going to happen sooner or later. That was the whole purpose of this "experiment" if you will, was to see how long TRW cast pistons would last under boost combined with way too much timing and not enough fuel. To be honest, I really only have one issue here: when I get time to continue the project, I have to choose which engine I want to put back in it's place. We have several assembled engines to choose from ranging from near-stock to a 13.5:1 compression, 9000 rpm 306 that was built for one of our bracket cars. Oh, and yes trw cast pistons will take some serious abuse, a lot more than people give them credit for. The engine that let go had been 3 different cars 4 different times. Heck, I've even got an old 460 on one end of the shop, an old 351 block on the other, and a board between the two of them used for storing built c4's and powerglides. Choices, choices...so many of them, so little time to work on it.
Russ, Where would I hook up a pyrometer, before the turbo in the exhaust manifold, or after it in the downpipe? Just curious, I might use a one-wire 02 sensor and a voltmeter for tuning purposes.
Still working..... Just finished the new shortblock. JE 8.3 compression inverted dome forged pistons (489 grams), '93 cobra hyd. roller block, static balanced rotating/reciprocating assembly, I have one more hard seat to install in the '75 351w heads that have been heavily ground on, just got through rebuilding the turbo and cleaning out all the aluminum pieces from the dead cylinders. I ordered a cam/timing set today, still have to machine the valve spring pockets for larger springs as well as finish a couple bowls and finally polish the combustion chambers. I must say this, those JE pistons are possibly the nicest pistons I've seen for under $600. They are way light too...considering the TRW's that I did have in this block were 645 grams, without the pin. The JE's are 515, with pin. Also, dad rounded up an "R" servo (c4 trans) from the local scrap-metal recycler, and I've assembled my own backyard-shift kit valvebody. Still need some clutches to assemble the trans, but I might just wait and use one of the spares from the shed. It's coming along, slowly, but surely. If any of you have ever driven a turbo-car, you know what I'm shooting for here. They are a blast to drive, one minute you're accelerating a bit slowly, the next second, a HUGE rush of power and torque plants you in the back of the seat. If you ever get the chance to drive one, do it....especially the buick GN's--they are waaay fun, for a 6-holer!
