Went to the track...

[87NAT]

My first pass out with new engine, turbo, and alky.

1.61 60 ft
7.3 @ 92 mph 1/8
22 psi
a/f#'s 10.8--11.0
timing 24.1 and 21

I did not finish pass...right after 1/8 mile knock started to come up quick and peaked at 9.4 degree. I got out of it. Finished 1/4 at 12.0@90 mph. A/F spiked to 12.7-13.0 during third gear.

Second pass: Added alky from 6.5 position to 8 and 2% fuel@WOT
1.58 60ft
7.2@95 1/8
22 psi
a/f#'s 10.4-10.5
timing 24.1 and 21

Same thing....knock came on strong during third gear right after 1/8 mile. Got out of it again... ran a 11.9@91 mph. The car runs good and strong from the line till the 1/8 then the a/f spikes.

I will be putting FP guage on windsheild to check WOT fuel but it seems to be okay for the 1/8 so I dont think it would drop for the last half of the track.

What do you guys think.

 

[turbows6]

I think you need to see what your fuel pressure is doing first. I'm going to guess that your fuel pump may be weak or going bad.

 

[87NAT]

Thats my plan this week. I hope its something simple like that...

 

[GNAT87]

Ed this sounds like what happen to my car. At the top end i was getting a lot of knock but none on the short end of the track but before i got the chance to try and figure the problem out i blew the HG....they say those Walbro's have been in the low 10's high 9's. If its not the converter you could try a volt booster and get a little more out of your pump...Just an idea though but Dusty probably is right

 

[87NAT]

Ed this sounds like what happen to my car. At the top end i was getting a lot of knock but none on the short end of the track but before i got the chance to try and figure the problem out i blew the HG....they say those Walbro's have been in the low 10's high 9's. If its not the converter you could try a volt booster and get a little more out of your pump...Just an idea though but Dusty probably is right

After talking with Dusty and looking back at my data rpm logs I am probably driving right thru the converter. I had only 100 or so rpm's drop between gears. My motor stayed at 5900-6000 rpm's from launch till when I got out of it in third gear. I cant say if thats what is causing the lean spike but the converter calculator on a few sites I checked are saying at least 20+% slippage.

I still need to check my WOT FP and see if thats good also. I will be lowering the boost back down and checking that tonight before I join the "headgasket" club.

 

[TURBO 6]

Yeah don't forget to lower the boost before you start checking the fp. Also if you haven't taken that tach out, check the rpm drop there to make sure its reading what the LM1 log works are saying.