Been a while with no update. I have been traveling for work and working to finish this swap with literally all my free time. A couple weeks ago I spent some time to fab a down pipe. What a Pita it is to fab when the car is in my garage and my power and welder is up the block at my apt. That means I have to fit a piece then go tack it then go back and check fitment then go back and weld it etc... for 6 welds lol. I came out pretty good though. Because of the turbos top mount placement there isnt much room to use 45s like a l28et.
Once together it started right up and with some adjustments idled fine. The car would fall on its face if you tried to do anything though. It would not boost at all and would flat out stall if you kept trying. With a friends help the dp was removed and we could see the turbo wasnt spinning at idle. Sometimes that normal but we also found there was no oil feed orifice and was afraid maybe the full pressure was locking the turbo up. To solve the problem I ordered a street 90 and taped the street side for a 1/16 plug. I then drilled the plug with a 2mm hole which seems to be the most common size for a turbo of this type. Not to pat myself on the back ut I thought it was a good solution lol. It also gave the soft line more slack, it was really tight without the L. So that didnt solve the problem. its good that its done though so whatever. In replicating the issue over and over I could see on the wide band it was leaning out off the charts. 1st I tried going from 145 to 230 jets and the problem was alomost the same. This time though when forcing the car to bog and kick it boosted just slightly for a moment then fall on its face again. No change on the gauge however. Here is a pic just to break up all this bs typing lol
Those were the biggest jet I had, so I drilled out to 350. Thats so big I would have never guessed to try and go there but you know what it improved. Again it would still fall flat if you dropped the throttle but it boosted to 7lbs and pulled well. Then I noticed the emulsion tubes were f16s, kind of in the middle as far as rich or lean. I was using F2's on my triples which are 2nd from the richest so I swapped those in along with larger air correctors and holy shit the car ran hard. It boosted to 11lb and slammed into 2nd like it was begging to break something. I also gave it some timing, 25 advance at idle. I also enriched the idle to 12:1. Those 2 things really helped the throttle response. It STILL wants to bog when you slam the gas pedal but you know triples do that too. Its just slight now and if you even rev it up slightly and dump the clutch to take off it doesnt do it. I will keep fine tuning more but I feel like that issue will never fully go away because both of those plates opening fully I cant imagine the fuel being sprayed and making it through the turbo with out some kind of initial lag. Another pic for fun
So now it seems to be at least streetable. I need to get the hood on, do a good check and seal the fan tot he radiator because the car is overheating very easily. Once on the road I can fine tune and maybe start leaning out the top end a bit. Right now it goes rich as hell (10-11:1) but that could be either the jets too large or the fact I only have 230 air correctors in there and with 350 jets they should be more like 360 air correctors lol. Rich is safe though so I am going to take my time on tuning that aspect. I'm going to try and keep up to date on the tuning aspect because I have spent hours and hours researching and found little to nothing on this set up. No tuning advice, no baselines not shit. So let the next glutton for punishment find this when they search and at least gain and idea of where to be when tuning. Two of the biggest finds for help were actually corvair sites and Beat sites because both of them seem to love draw through set ups. The corvairs even have a guy modifying dcoes so that one throttle shaft will open like normal and the other will open with an actuator as needed by a vac/boost reference. That may be what they do to eliminate the initial bog when gunning the throttle. I may start researching that modification to see if I can do it myself.