L67 F-bird

[charlief1]

Sounds like it may be a little rich or you're heavy on the foot. Have you tried checking the data yet?

 

[MNcarbturbo]

Yeah Ive looked on my HP tuners scans and nothing is overly bad. It is pulling 14% fuel out at idle but only like .4% at cruise. Thats running with cruise control all the way going 60-65.

I should say the last tank was 80% highway that netted 16MPG. There was a tank of 98% highway that managed 19MPG.

 

[charlief1]

Have you tried alky or water/alky injection on it?

 

[MNcarbturbo]

No. I really dont think its needed. I would consider it if after I get the 3.4" pulley and headers on and still get knock retard but otherwise no.

 

[charlief1]

A small spray with a water/alky mix might just give you a little more mileage. Seen it before on carbed engines.

 

[vicious6]

Thanks!

I have been driving it daily for a few months now. The MPG is dissapointing. I was hopping for 27 but Im only getting 16. Dont know why its so bad as I am using a stock Regal GS timing, fuel and air flow tables but theres a chance I missed something in the tune. The O2's are good, and the car pulls great, doesnt smell gassy without the converter. Its a mystery to me.

Does it have 3.42s?

 

[MNcarbturbo]

Yes. Turns at 2000RPM at 60MPH.

 

[turbojkt]

Yes. Turns at 2000RPM at 60MPH.

Is the torque converter locking up at crusing speeds? Is 2000 RPM at 60MPH normal...or is it a little high? Anyone know for sure?

 

[brento231]

Love your project. I just pulled the L67 out of my 97 ssei last night. It's setting on next to the 3800 and 4l60 out of a 96 donor camaro. I've been pondering the supercharger inlet to fit it in my 79 Malibu. Anyone considered mounting a 90's era SBC serpentine crankpulley to the front of the harmonic balancer and moving the s/c forward?
Also, l'm suspicious it's the 3:42 gears. My Bonneville had 2:93 final drive with 26in tires. 4200 lbs it would do 26 mpg on trips.

 

[MNcarbturbo]

It should be easy on a G body. The firewall is so more forgiving that it wont be near as much work. I dont know about moving the SC ahead. You would have to redrill all the mounting holes and the intake hole for the supercharger outlet wont match up. Id keep it in the stock spot and U the SC.

Also, watch out for wiring stuff. The only stuff you will need off the camaro motor will be the accessories and pan for the most part. I used the stock firebird harness, but you will probably have to use the bonne harness. The 96 is still OBD 1.5 so the wiring will be different between the motors.

 

[MNcarbturbo]

Been a long time since I updated this. Car ran good this winter and continues to run this summer. I wanted more hp so I bought a 3.4" pulley and put it on. Had a bit of KR so I built a window washer injection system (alky for you rich people ) and it took all knock away. This was on 89BTW, I was planning on running 91 but its not needed. Still searching for more power I stuck a slightly more agressive timing table in it out of a 04 Comp G GTP. Still no knocks. I am thinking that with headers and 91 and a cam I would be able to run a 3.0" pulley. And be in the high 12's.

Also put a set of BMW wheels on it. Yeah the bolt pattern isnt the same but ive never seen any problems with them and it looks way better. Plus its hard to find WS6 wheels up here. I encountered real bad wheel hop so I ended up building a set of lower control arm lowering brackets to get the LCA at a upward slope so the rear didnt unload itself and smack into the quarters. Worked great, still spins but its better.

 

[charlief1]

LOL You did an IC relocation on an F body. Not suprised it worked well either.

 

[KrisW]

Did you ever figure out the problem with the mileage?

Everything else looks great and is a real inspiration!

 

[MNcarbturbo]

I found out it gets considerably better milage in the summer. It pulls 22 or so MPG at 65MPH. I should be able to find some in the tune.

 

[murphinator]

you should be in the mid 13's running a 3.4 with no knock , especially if your seeing 17* or more of timing up top.

Keep up the good work and lets see some track vids and slips , I am very curious to compare 60 ft ,et , and trap with what a well supported w body would do on a 3.4

 

[MNcarbturbo]

That fast huh? I ran a 15.03 last time I ran at the track with a 2.46 60ft and trapped at 93MPH. It spun BAD, but I have 255/45/17 Eagle GS's with a 220 treadwear and the LCA relocation brackets so it should hook better.

Right now its stitting at 13-14 degrees up top. I can turn the alky up a bit and run 91 and would for sure be able to run 17+ of timing.

I was going to take it to the track last weekend but it rained. I will be running it within the next month.

 

[murphinator]

That fast huh? I ran a 15.03 last time I ran at the track with a 2.46 60ft and trapped at 93MPH. It spun BAD, but I have 255/45/17 Eagle GS's with a 220 treadwear and the LCA relocation brackets so it should hook better.

Right now its stitting at 13-14 degrees up top. I can turn the alky up a bit and run 91 and would for sure be able to run 17+ of timing.

I was going to take it to the track last weekend but it rained. I will be running it within the next month.

I have had 3 different 3.4 pulley cars with proper supporting mods , fuel etc.. to run the 3.4 at the track , the 2 with headers and rockers both ran 13.3 for me ( one was stock 2.93 gearing the other had 3.29's) and the stock cam/rockers car with plog/ported rear/ 3" exhaust/ported tb etc ran 13.5 all 3 were full weight cars other than spare tires , jacks etc... removed and some track prep. These times were with no spray.

One was a 2 door gtp , one was a 4 door gtp , and the other was a 4 door regal gs , all trapped in the 103/104 range and one of them I sprayed to 12.2 @118 and another to 13.1 @109 on spray yes 3800 sc's get along very well with spray.All were also run at my local track which is approx 100ft above sea level and I only race spring and fall when density altitudes are well below sea level (-500 to -1300) so if your racing at altitude when its 70-80* its going to kill your et's

your 60 foot is killing you RWD should 60 foot better than that , get some dr's or slicks or borrow some if you dont get sub 2.0's out of your new tires - common bolt pattern for anything gm rwd small pattern back to the early muscle cars someone should let you borrow a pair for a pass or 2.

your current trap of 93 makes me think its currently a low to mid 14 sec car hooked up , point of reference : my daughters nearly stock fwd gs ran 14.4 @96 for me with just track prep and a homemade fenderwell intake , colder plugs & stat on a crappy 2.2 60 foot due to its stock eagle ls's at the time , my dr's should have put it 14 flat or 14.1 if I knew I was going to take the detour to the track that night lol.

 

[MNcarbturbo]

Sounds great! Sounds like I am going to need a helmet then.

My track rescheduled the rain day so I will be headed up on July 6th.

 

[MNcarbturbo]

Ran at the track today. Not a sucess but not a failure either. It was 85, slight breeze and sunny. Low attendance, rain makeup day from a few weeks back Some people complained about the track being slippery. Ran a 15.34 first run, knocked all the way, spun bad, 2.46 60ft, trapped at 92.74. Went back, let it cool off, added more alcohol, went up and raced it. 14.76 at 92.83, 2.17 60ft. Ran it again and got a bit greedy, spun off the line, 15.09 at 94. Every run after that was a 14.85-15.20 at 93 with about a 2.36 60ft.

My 14.74 run trap speed was 92.74 and last falls run was 93.83 so it actually got slower on the big end.

Woulda thought that with 3-4 more PSI, better tires, and more timing with no knock it woulda ran better but with the exeption of that one 2.17 60ft time it ran the exact same as it did last fall. That 2.17 didnt spin a bit but I was unable to replicate that good lauch, just spun a bit every time. Reduced the tire pressure about 5PSI and it didnt help. IAT's were around 100 no matter how long it sat.

Nobody else was super strong it seemed. There was a STR8 challenger that ran 14.5's all the time and hes got 100HP on me. Procharged C5 that ran high 12's that shoulda been in the 11's.

Needs drag radials or a trip to a different track just to see what will happen.

Heres a video but I didnt realize the video function on my camera is so bad and all you can hear is the mustang next to me squeeling forever. Click to open

 

[charlief1]

The fact that your time w was better and your speed was slower isn't unusual at all. Have you tried adding some weight to the back of the car to get better traction?