Well, today i finally had everything ready for a test drive. so i did. i noticed that the turbo (Garrett T25) started to spool at 3K, and when that happens, the car dies, almost like it went out of fuel. I Tried again looking at the Fuel ratio gauge and at that moment fuel ratio goes down. I think it may be fuel related, but im not sure if its the carb or some thong else.
My setup is:
E16s engine 9.0:1 CR
T25 with Waste gate set at 7 PSI
A blowthru setupwith a carb prepared for this.
Another thing im not sure is how to regulate the BOV.
Thanks
Something about the setup or because of the problem i mentioned???
Tomorrow im going to a guy that installs turboes and who sold me the fuel pressure regulater and BOV to se if he can help.
That could be a problem since i have stock ingnition.
But still i see a lean mixture when boost starts and that wouldnt be caused by ignition, right?
A lean mixture means the air-fuel ratio contains too much air. The spark has nothing to do with this. It sounds like your carb is not delivering enough fuel. If you are using the stock carb, this will certainly be the case.
Are you using a wide-band oxygen sensor to measure air-fuel ratio? If you are using a standard O2 sensor, it is very inaccurate, essentially useless.
no the spark has nothin to do with it, but its also something else to look for when u figure out how to make your a/f ratio correct, is the carborator all boxed in correctly and what not, no vacuum leaks?
What did you do to prep the carb? What kind of carb is it? (IIRC, you were using a Rochester off a Chevy or something right?)
I don't know much about Rochesters, but I know you have to replace the floats and the jets, etc. when you turbo a carb. How are you introducing more fuel at boost? You may be running to lean at boost (so lean that the car dies). I would run an ijector that sprays at boost into the intake manifold or have some sort of vacuum actuator that opens the secondaries at boost, and rejet the secondaries, that way you're not running rich all the time. A lot of weber guys run like that, and a book I have describes a way to do it that way. Remember that a carb can not compensate for the extra density of air, it knows volume, so that might be your problem.
lol actually that is a great idea, fit a injector on top to spray at boost, im sure u would need a bunch of electronics then but it'd be neat and different
lol actually that is a great idea, fit a injector on top to spray at boost, im sure u would need a bunch of electronics then but it'd be neat and different
A book on turbocharging describes a kit you can you to that, I don't remember what it's called, I'll have to look it up later. I can't imagine it being any more complicated than the fuel part of an N2O wet system.
Are you running an electric fuel pump? the mechanical pump that came on most carb'd models will not be up to task.
Today i managed to make it run well, the thing is that the carb was prepared for turbo, its not the stock carb, its from a VW Gol, i think you dont have these there. The carb was re-jetted for the turbo use, but i think the jets are to big, stock ones are 130 140 and now it has 140 220, i close secondary and it works nice, not great but almost like before the turbo. Tomorrow im going to find smaller jets specially for the secondary, if i use it with the 220 it dies, its to much fuel.
What jets do you think would go right?
I'm not sure about jet size, but when does the secondary open? If it opens before boost, then its bad. Most progressive carbs open the secondary at WOT, fine for stock, but not good for turbo.
The turbo book I have shows a 2 barrel setup reworked so that the secondary is not opened mechanically but opened with a diaphram spring is overcome by the pressure in the intake manifold. You have to use a mead valve connected to the diaphram and the the intake manifold to work. Looks like a sick setup, simple and effective. I wish I had a scanner, I would scan the page for you.
The book is
Turbocharging by Hugh MacInnes. It would be a tremendous help if you can get your hands on it. Some of the more well-versed turbo guys might be able to better describe it.
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