Twin-Charged Bonneville running again
I finally rebuilt the 3800 in the twin-charged bonne. I had blown it up pretty bad due to a slipped 1-2 shift and hitting fuel cut under 14psi boost. I made sure to install an MSD DIS-4 system so I now have a soft-touch rev limit. Fuel cut is set at 7500rpm, way out of reach.
The twin liquid-air intercooler system is done, the fan, pump, etc. I ran 3/4" hose twice the length of the car, wye'd it into two 5/8" hoses to each intercooler, and then wye'd it back together to go into the front-mount heat exchanger, then back to the tank (3-gal "bubba keg" in the trunk), and out to the pump which is mounted in the rear of the car under the trunk floor. It is so efficient, it provides ambient air temp in the intercoolers at all times. The temp drop across the turbo i/c is about 10deg and the */c i/c is about 15 deg. Temp drop across the radiator is about 20 deg. It is always ambient air temp coming out of the rad.
I am having trouble with the Walbro fp. Come to find out they don;t run well when not immersed in fuel. The bonne fuel tank is quite wide and 1/4-tank is below the level of the gerotors in the pump! I am looking at a few options, including sumping the tank and running an aeromotive pump system.
The turbo came back from the rebuild ($750.00-worth UGH!!!) good as new. New turbine shaft, new turbine hsg, bearings and seals, too. I am using oil about 1qt/1000 miles. I left a pretty rough finsh in the cyl (hone sucked), so i'm hoping it will seal up after a while. it has about 6-7K miles on it now. It runs very string, but the fuel issues are plaguing me. I plan to run a modified L32 fuel rail and an aftermarket regulator. The stock regulator will only boost-compensate up to 10psi, then it stops rising. Not good when running 16psi+.
I am also running it on a LS1 MAF this time. Once I get the fuel issues worked out, I plan to start tuning it. I'll post as news comes in.
BTW, my Grand Am (see sig) ran at the Pontiac nats last week in Ohio. My new pb for any car I've ever owned: 12.38@117mph. It will go 11'* in the current state of tune with a little more practice launching.
1988 Grand Am SE 2.0 Turbo
1996 Bonneville SSEi Twin-Charged
Last edited by pontiacjeff; 08-18-2009 at 05:25 PM.
Reason: add track times