If you need any 2004r advice I have one behind my SBB. Definitely makes the car a great cruiser with 3.73s
I will probably take you up on that at some point. Unfortunately my nights and weekends are spoken for until mid May, so the tranny is going to have to wait. I might be able to get a paint job snuck in on it. Weather is getting nice down here though. I need to get it going soon.
I got the second 2004r transmission working it in this past weekend. Upon a test drive tonight I realized the car is running real rich. I need to lean it down and bit and see if I can get a vid posted up. It was 80 and sunny today so I drove the car to work today. Bunch of guys wanted to come out to check it out. It gets a lot of attention where ever it goes still.
On low boost (8psi) I tuned for 12-12.5 afr. The guys that tune for 10 are using fuel to cool things down on high boost. As long as the engine doesn't ping NA or close to NA tune is okay. I picked up a ton of power going from 10.5 to 12.0. Tweaked it down to 12.5 and saw no notable improvement so I kept it 12-12.5. I did use 92 octane pump gas though. I originally ran 87, but pulled a lot more timing. With pump premium I ran 30-32 degrees total on 8psi with stock pistons. Never pinged.
Now that is some very useful first hand info that will help all of us Boosted Buick 350 guys! Here is the dyno graph of my car... We had to abort the run due to tire rub and a header leak but it still made 450 HP at the tires. Have a look at the air fuel ratio. Basically 12:1 the whole run:
It was about 17 PSI, using both air to air intercooler and water meth injection. Bone stock CSU carb no mods to it, right out of the box. There were a few issues such as a converter that was slipping as it could not handle the power. Got a $1800 converter to swap in now.
I shot for between 12 and 12.5 AFR. I ran a Mallory 6 box with boost and start retard.. 87 octane only. Setup was like this. 20* initial with 14* mechanical all in at 2K with a 2800 stall. 10* start retard. Map sensor pulling 1* for lb. of boost. Methanol came on with a full spray at 4 psi. Boost gauge said I was running 12PSI. Not sure how accurate that was. I used vacuum advance too. Jay
Thanks for all the advice. I will be tuning this weekend. When I say it was running rich, it pinged my gauge at 10 at part throttle, it would creep up to 12 after a few thousand RPM. I can't recall off the top of my head what I am running for timing. I will check it this weekend as well. I am running the MSD 6BTM box and am pulling 1 per 1psi. I have some 11lb springs and a meth injection kit I want to install, but want to get it tuned at this combo first. Then I can see if I want to try more. Stock pistons, early rods, stock bore and when I re-ringed the engine I never checked gap on rings, I installed them out of the box (I was 16 at the time and had never heard of setting gap on a ring. Plus I never had dreamed of turboing the car 12 years later either). Does have upgraded springs. This car was my first car when I turned 16. I crashed it two weeks after I had it racing my buddy in his 75 Blazer. 4 wheel drum manual brakes and the car could barely stop above 40mph. We were side x side on a back road coming into a speed limit area. Tow truck pulled onto road what seemed like a ton of distance in front of us, but my car could not stop, slide it sideways and hit the safety bar into my passenger fender and bent the hood. I did get a GS hood for the car out of it though! My buddy sold that Blazer when we were 18. He called me tonight all excited saying he bought it back from the guy he sold it to. Told it was time we get them lined back up again.
Had a little extra time to work on the car this weekend. I pulled the valve body plate on the 2004r and made the 1-2 shift hole smaller. I was getting tire chirp with barely any throttle that I did not want. I went from 0.096 to 0.085 on the hole and put it back together. 1-2 shift was much better. Firm, but not chirping the tires at part throttle. I also was working on the PVRC jets. I was running 0.045 and went to 0.041. At cruise I have 14-15 inHg. AFR at 13.5. PV of 10.5. When I would give enough throttle to open PV, AFR would be ~12.2. With the 0.045 PVRC jets it would be bogged at AFR 10. Slowly rolling into throttle at 12 inHg the AFR creeps up to 14, but no pinging. Does that seem normal? Seems like a PV of 12.5 would be nice if they made one.
If the AFR is going to 14 under load, it sounds like the PV needs to come in even sooner. Either that, or slightly more main jet. If you add main for the light load lean condition, you'll find that the transition from idle circuit to main might go rich. Air bleed correction comes into play, but that takes a LOT of trial and error. Personally I'd rather see a temporary rich condition than a lean one.
Has anyone modified a PV to get it to come in sooner than a 10.5 inHg? I am assuming it is lighter spring or cutting of spring? I would rather go that route then adding to the main jet because the cruise AFR are good around 13.2. I will check on Thursday what AFR is with boost. I wasn't getting onto that hard last drive.
That's still pretty rich for cruise. A two stage power valve has two vacuum points, usually one around 14" the second at 10". I've never tried one on a boosted setup but they're AWESOME for a driver. Allows for very economical jetting, but still good response. They're pricey though. $40-50. I've also made a tuneable valve that has 2 knurled knobs, one for adjusting spring pressure, the other to lock it. I don't think it would be possible to make without a lathe though.
Thanks for the input. I might try to modify one I have. My main jets are 64. I was going to drop a couple of jet sizes to bring up the cruise AFR, but the jet kit I bought only goes down to 64. I'll have to get a set with smaller jets. Can you get 1/4"-32 set screws and drill them for smaller sizes or do you need a certain shape in the jet?