Putting a turbo on the ol' 1915

[Therealkoop]

Quick update:

Tried going up to a 135 main. Makes the car run great above 10psi, but anywhere below that is way rich. I guess I should've expected that, the car should run about the same up to 10 psi.

Moved down a spot to a 175 air jet. Looks like it gave me a little bit of fuel up top. AFR below 10psi is about the same as it was before (11.3), and now above 10 its favoring 11.7ish. with the 185 jet it was more favoring 12ish.

[Therealkoop]

Engine seems to be running well at 15 psi.

However, still some problems that I will likely get to resolving at some point. Right now it runs well enough and doesnt show signs on knock, so Im just enjoying driving it. It was 90+ degrees outside the other day and I beat the piss out of it to see how it would respond.

1. Fueling is rich off boost. Im lucky to see 13:1 while cruising at 60mph which is probably my average speed. The turbo is small and once you give it enough throttle in 3rd gear to surpass 50mph it gets to 0 MAP or 1 PSI. This is enough to cause the modular rings to start doing some work, and my AFR sits in the high 11's. Putting a larger turbo on seems counter intuitive, modifying the rings likely wouldnt help and would cause issues at high boost, and I will do an ecotec swap before I go EFI.

2. Spark is garbage. Im running 20* at the moment due to the 15psi. However, since im using a limited 009 dizzy that is also my timing at cruise. Thinking of getting an electronic 009, locking it out, and getting a CB black box. Obviously this would drop temps and increase mileage a lot, but MAYBE it would give me enough torque to get back into vacuum range when at 60MPH.

Aside from going EFI, I dont know if there is a great way to resolve my cruise AFR issues. By the time I would deal with EFI I would probably just move to a water pumper. This is purely a cruise around or screw off vehicle so its not particularly important to have everything at 100%. Still, it gives me stuff to tinker with which is what this vehicle always has been for.

[madmike]

you can always do a 'Draw threw" my crusing afr's are 15-17

[buguy]

There is definitely a draw going to a water cooled engine. I totally get it. If I had half a brain I would have stuck a subie engine in mine and been done with it.

[panel]

We have cookies on the dark side

There is definitely a draw going to a water cooled engine. I totally get it. If I had half a brain I would have stuck a subie engine in mine and been done with it.

[Schweg]

There’s some fun missing doing that


Sent from my iPhone using Tapatalk

[Therealkoop]

Im too invested in my blow through setup right now to suddenly switch to a draw through. Also..... dual carb blow through looks so cool!

[woodsbuggy1]

Please don't give up on your setup. The aircooled engine does have challenges but it way better at so many levels than a waterlogged engine.
Kenric

[madmike]

"waterlogged" I like it! ,,,always called them waterpumpers

[Therealkoop]

Science time.

Engines been running strong, no problems and just been driving it.

For science though I ordered some parts from CB; 34mm vents and some 33mm modular rings. I expect some tuning to follow these changes so Ill report back. I think I have driven this enough now that I should be able to perceive changes in power/driveability. The mod rings I have do the trick, but they are pretty goofy, and the restriction is much greater than with this CB setup.

[Therealkoop]

Science

Swapped in the 34mm vents and CB 33mm mod rings. Got the idle tuned up and good to go. Cruise within vacuum is around 13.8:1.

There is a HUGE lean/flat spot now while stepping into the throttle, and if I pound through it, I run lean, didnt really stay in it enough to be able to say. Runs terrible.


Going to go up in air jet size to try and drown out the flat spot, and up in mains to make up for the change in the air jet and to bump up the overall AFR.

Edit, adjusted mains and airs. Right now the flat spot is essentially gone, but by doing so my top end is lean. Moved all the way up to 155 mains and 205 airs.

The good: Cruise AFR is around 14:1. It is 12:1 with the prior setup.

Boost MIGHT be building quicker, hard to say so far.

The bad: AFR is around 12.2:1 through the main RPM band (WOT), but leans to 13:1 at the top. Im hoping that going up in the mains EVEN MORE will help alleviate the flat spot, because I am going to have to drop the airs smaller to get the top end AFRs to calm down.

The 33mm CB modular rings basically do nothing. The 1mm difference between them and the vents is probably not enough to matter. Previously I ran 3mms smaller than the vents with the home made rings. Playing with the throttle while cruising, as soon as you hit 1psi there was a drastic and noticeable drop in AFR. With this setup, it doesnt occur unil 4-5psi, and its effect is much less.

Ill give it another afternoon of tinkering, at worst I will go back to the prior setup which was fine.

[Therealkoop]

Current jets

160main
195 air
55idle
34vents
33 CB mod rings

Cruise is right around 14:1
wot starts at 11.4 and ends at 12.5

Seems to run well, cruise is great, a slight flat spot at around 1 inch of vacuum. The mid range fueling gets heavy which makes the car feel "rubber bandy" but once it gets to 10-15 psi it REALLY takes off.

The mid range fueling is so rich, that I can beat on it a little and cause the motor to simply stall out. I have never had this issue except on in the most extreme of situations. I have had it happen while just driving down the road and fanning the throttle.

Overall, Im going to drive it for a bit and feel it out. Im 50/50 on just going back to the 29mm mod rings and 32mm vents.

[Therealkoop]

33mods and 34 vents are a bust. Fueling was just too inconsistent, I determine it to be a lack of restriction on the mod rings. 1mm is not doing the trick, and it does not provide enough fuel versus charge pressure. I think 33 mods with 36 vents would probably be much better, but I dont want to use 36mm vents on my dual 40's.

I reverted back to 29mm (home made) mod rings and 32 vents. The car runs rich at cruise now, but pedal is linear to power. More pedal = more go. With the 34mm vents there were both lean/rich flat spots on either wide of 0 MAP, and the vehicle was much less drivable with these flats spots. Power felt more like rubber bandy, with lean spots and fuel bog. Fueling was also inconsistent at wot, starting at low 11's and running up to mid 12s.

The old setups fueling was dead consistent at 11.4:1. I liked the top end pull that the 36mm vents provided, so I upped the boost to 18PSI, which moved fueling to 11.8:1.

So far so good. No indications of knock, no plans on further modifications at this time.

[madmike]

what happened to only running 5-7 lbs?

[buguy]

Haha! Don't we all say that at the beginning?!