NJFBOA - Home of New Jersey's Camaros and Firebirds - View Single Post - Getting my new 406 SBC installed, running, and driving

IROCZman15 · 05-17-2021, 07:22 PM

I can get into more details about the 1st gear bog if anyone would like to discuss that further. Spent lots of time looking at past datalogs and examining the VE table and modifier tables. Also checked as much mechanical stuff as I could (fuel pressure gauge reads 62psi and barely takes a dip when engine is revved, all exhaust bolts tight, all injectors are spraying equally, zip-ties the notoriously unreliable injector connectors to stay locked in, checked a few plugs, etc). Did some test driving, the car acted better, but the true test would come on the track.. which I went to yesterday for my last Drag race day until probably the Fall of 2021. Also in the tune, I took away the ECU's ability to be in closed loop all the time. One of my thoughts with this bog, is that the ECU is spiking rich, lean, rich lean so quickly through 1st gear it cant make up its mind about what to change quick enough. So for the first two passes, I kept the ECU in open loop until 4,000 rpms. For the second two passes, I kept the ECU in open loop for until 4,500 RPMS. The car didn't bog or stumble at all in first gear, but there was usually a very quick spike in the AFR trace. I've been told that on initial "tip in" with no air filter and a TBI, I should expect a spike/blip. So by keeping the ECU in open loop past this point, it avoided making ANY changes, and it really only came in to adjust my CL fuel compensation when I was higher in the rpms in 1st, 2nd, 3rd gear. I'm happy about that.

Also, I decided to buy the most inexpensive front DRAG strut available to see how the car lifted at launch. I bought the Lakewood 90/10 Drag strut. I know there are adjustable struts for big $, but I do not have the budget for those. These lakewood's do come up quick. I filmed a few short videos of them compared to the koni yellows when I did the strut swap. I have yet to edit or upload those videos, but I will do so in the next week. The lakewood 90/10 drag strut is not as "treacherous" on the street as some people have made it seem. The car was a bit floaty on the road, but I also had no front sway bar, skinny front tires, and the 90/10s. The did help the car lift and transfer weight better, but I launch at such a low rpm, that They aren't able to do their best job just yet. more on all that in the future.

Front tires were at 43 psi all day and rear tires were at 19 psi all day. Lakewood non-adjustable 90/10 struts up front and the Koni yellow shocks in the rear were at 4/5 all day which is medium-tight.
-fun note, every car in the lane next to me all 4 passes ran in the 9 second zone, so I felt like a total chump!

Pass 1:
Did a 6 second burnout, and now I am getting used to shifting into 2nd gear during the burnout, before I would just do 1st gear. My buddy John was there and we decided to see if I could get a little more RPM off the launch by not only going heavy on the foot brake, but also using the E-brake. The car began to roll just as I got close to 2,100 rpms and almost rolled the beams, so I just left. Datalog showed I went WOT at 2,228 rpms and the converter flashed at 3,015 rpms. No BOG ! Shifted 1st gear at 6665 and landed in 2nd gear at 4,732. It was right after the shift, when I saw the red light on the dashboard, and realized that I had not fully put het E-brake back down!! What a dope. So I fully released the e-brake, shifted 2-3 at 6,530 and landed at 4,870 rpms. Crossed the line at 6,214 rpms. Entire run was at 34 degrees of timing and target afr was 12.8, DA was 1365, Temp was 71 deg, and Humidity was 42%.

video: https://www.youtube.com/watch?v=eZJG5RGI_sw

Pass 2:
Another 2-gear, 6 second, mid rpm burnout, just enough to get the tires to smoke a puff. Footbrake launch at 1575 using the ebrake, and I put it down fully this time. Converter flashed at 3,018 rpms and I shifted out of first gear at 6684 rpms and landed in 2nd gear at 4870 rpms. Shifted 2-3 at 6596 and landed at 4888 rpms. Crossed the line around 6,100 rpms. Target afr was 12.8, Timing was 34.0 deg, DA was 1286 Temp was now 70 deg, and humidity 44 deg.

video: https://www.youtube.com/watch?v=5D2oIybKBpw
-this video John filmed finally gives me an idea of how the car leaves the line. I can try to view itin slow-motion, but I can't see any tire spin, rear body squat, or anything bad.. it just leaves from such a low rpm that it takes a little effort to get up-and-go...

Pass 3: (quickest pass ever, so far)

Mid rpm 2 gear burnout for 5 seconds. Launched from an idle this time at 933 rpms and the converter flashed at 2950 rpms. Shifted out of first at 6,545 and landed at 4841 in 2nd. Shifted 2-3 at 6593 and landed at 4910. Crossed the finish line at 6,202 rpms. I had bumped the timing up one degree to 35.0 deg, and we also leaned out the target afr a little bit to 13.0. DA was 1174 temp was 68 deg and 48% humidity. In the lane next tome was my friend Kevin who runs high 9's in that awesome Trackhawk.

video:
https://www.youtube.com/watch?v=8M__Jokh5nU

Pass 4:

6 second, mid rpm, 2 gear burnout. Launched basically at idle again since my 60 foot was great last time. Converter flashed a little low this time, at 2812 rpms. 1-2 shift was 6736 landing at 4,876 and the 2-3 shift was 6,552 landing at 4,847 rpms. Finish line rpm was 6,230. Target AFR was 13.0 and ignition timing was 35.0 I did not remember to check weather data before this last pass.

video: https://www.youtube.com/watch?v=1pGTGxinJOE

So overall, man, I was really realllly hoping for a timeslip with an 11.79x et on it at around 117 mph. I am o.k. with the timeslip from pass 3 which was 11.8000 at 116.19 mph. I do think it is possible, but I will have to wait for a while as I switch the car over to autocross and car show mode for the summer months. I am also set to have the roll-bar installed in June.

After getting home, and as always keeping an eye on the high oil pressure, I removed the drag wheels to give them a wash since they will be going away for a few months while I switch to autocross. At this time I noticed a crack in the hub of the drivers side front Jegs SSR wheel. WOW. scary. I removed the passenger wheel and noticed a similar crack. Wow, extra scary. I have never ever, not even once, used an impact gun to tighten these down. I always, always, always use my mechanical torque wrench. I bring them to 90 ft/lbs each, and then bring them to 110 ft/lbs each. How the heck could these have both cracked? I do think they are salvageable, and I am going to research what to do. Cast aluminum, so I am thinking the crack can be opened up to its deepest point, welded with aluminum filler rod, and buzzed down. Thoughts?

Drivers side:

Pass side:

05-17-2021, 07:22 PM	#337
IROCZman15 10 Second Club / Meet Coordinator Join Date: Dec 2004 Location: Roxbury, NJ Posts: 2,101 iTrader: (8)	I can get into more details about the 1st gear bog if anyone would like to discuss that further. Spent lots of time looking at past datalogs and examining the VE table and modifier tables. Also checked as much mechanical stuff as I could (fuel pressure gauge reads 62psi and barely takes a dip when engine is revved, all exhaust bolts tight, all injectors are spraying equally, zip-ties the notoriously unreliable injector connectors to stay locked in, checked a few plugs, etc). Did some test driving, the car acted better, but the true test would come on the track.. which I went to yesterday for my last Drag race day until probably the Fall of 2021. Also in the tune, I took away the ECU's ability to be in closed loop all the time. One of my thoughts with this bog, is that the ECU is spiking rich, lean, rich lean so quickly through 1st gear it cant make up its mind about what to change quick enough. So for the first two passes, I kept the ECU in open loop until 4,000 rpms. For the second two passes, I kept the ECU in open loop for until 4,500 RPMS. The car didn't bog or stumble at all in first gear, but there was usually a very quick spike in the AFR trace. I've been told that on initial "tip in" with no air filter and a TBI, I should expect a spike/blip. So by keeping the ECU in open loop past this point, it avoided making ANY changes, and it really only came in to adjust my CL fuel compensation when I was higher in the rpms in 1st, 2nd, 3rd gear. I'm happy about that. Also, I decided to buy the most inexpensive front DRAG strut available to see how the car lifted at launch. I bought the Lakewood 90/10 Drag strut. I know there are adjustable struts for big $, but I do not have the budget for those. These lakewood's do come up quick. I filmed a few short videos of them compared to the koni yellows when I did the strut swap. I have yet to edit or upload those videos, but I will do so in the next week. The lakewood 90/10 drag strut is not as "treacherous" on the street as some people have made it seem. The car was a bit floaty on the road, but I also had no front sway bar, skinny front tires, and the 90/10s. The did help the car lift and transfer weight better, but I launch at such a low rpm, that They aren't able to do their best job just yet. more on all that in the future. Front tires were at 43 psi all day and rear tires were at 19 psi all day. Lakewood non-adjustable 90/10 struts up front and the Koni yellow shocks in the rear were at 4/5 all day which is medium-tight. -fun note, every car in the lane next to me all 4 passes ran in the 9 second zone, so I felt like a total chump! Pass 1: Did a 6 second burnout, and now I am getting used to shifting into 2nd gear during the burnout, before I would just do 1st gear. My buddy John was there and we decided to see if I could get a little more RPM off the launch by not only going heavy on the foot brake, but also using the E-brake. The car began to roll just as I got close to 2,100 rpms and almost rolled the beams, so I just left. Datalog showed I went WOT at 2,228 rpms and the converter flashed at 3,015 rpms. No BOG ! Shifted 1st gear at 6665 and landed in 2nd gear at 4,732. It was right after the shift, when I saw the red light on the dashboard, and realized that I had not fully put het E-brake back down!! What a dope. So I fully released the e-brake, shifted 2-3 at 6,530 and landed at 4,870 rpms. Crossed the line at 6,214 rpms. Entire run was at 34 degrees of timing and target afr was 12.8, DA was 1365, Temp was 71 deg, and Humidity was 42%. video: https://www.youtube.com/watch?v=eZJG5RGI_sw Pass 2: Another 2-gear, 6 second, mid rpm burnout, just enough to get the tires to smoke a puff. Footbrake launch at 1575 using the ebrake, and I put it down fully this time. Converter flashed at 3,018 rpms and I shifted out of first gear at 6684 rpms and landed in 2nd gear at 4870 rpms. Shifted 2-3 at 6596 and landed at 4888 rpms. Crossed the line around 6,100 rpms. Target afr was 12.8, Timing was 34.0 deg, DA was 1286 Temp was now 70 deg, and humidity 44 deg. video: https://www.youtube.com/watch?v=5D2oIybKBpw -this video John filmed finally gives me an idea of how the car leaves the line. I can try to view itin slow-motion, but I can't see any tire spin, rear body squat, or anything bad.. it just leaves from such a low rpm that it takes a little effort to get up-and-go... Pass 3: (quickest pass ever, so far) Mid rpm 2 gear burnout for 5 seconds. Launched from an idle this time at 933 rpms and the converter flashed at 2950 rpms. Shifted out of first at 6,545 and landed at 4841 in 2nd. Shifted 2-3 at 6593 and landed at 4910. Crossed the finish line at 6,202 rpms. I had bumped the timing up one degree to 35.0 deg, and we also leaned out the target afr a little bit to 13.0. DA was 1174 temp was 68 deg and 48% humidity. In the lane next tome was my friend Kevin who runs high 9's in that awesome Trackhawk. video: https://www.youtube.com/watch?v=8M__Jokh5nU Pass 4: 6 second, mid rpm, 2 gear burnout. Launched basically at idle again since my 60 foot was great last time. Converter flashed a little low this time, at 2812 rpms. 1-2 shift was 6736 landing at 4,876 and the 2-3 shift was 6,552 landing at 4,847 rpms. Finish line rpm was 6,230. Target AFR was 13.0 and ignition timing was 35.0 I did not remember to check weather data before this last pass. video: https://www.youtube.com/watch?v=1pGTGxinJOE So overall, man, I was really realllly hoping for a timeslip with an 11.79x et on it at around 117 mph. I am o.k. with the timeslip from pass 3 which was 11.8000 at 116.19 mph. I do think it is possible, but I will have to wait for a while as I switch the car over to autocross and car show mode for the summer months. I am also set to have the roll-bar installed in June. After getting home, and as always keeping an eye on the high oil pressure, I removed the drag wheels to give them a wash since they will be going away for a few months while I switch to autocross. At this time I noticed a crack in the hub of the drivers side front Jegs SSR wheel. WOW. scary. I removed the passenger wheel and noticed a similar crack. Wow, extra scary. I have never ever, not even once, used an impact gun to tighten these down. I always, always, always use my mechanical torque wrench. I bring them to 90 ft/lbs each, and then bring them to 110 ft/lbs each. How the heck could these have both cracked? I do think they are salvageable, and I am going to research what to do. Cast aluminum, so I am thinking the crack can be opened up to its deepest point, welded with aluminum filler rod, and buzzed down. Thoughts? Drivers side: Pass side: __________________ 1987 IROC-Z - modified Last edited by IROCZman15; 05-17-2021 at 09:14 PM.