Getting my new 406 SBC installed, running, and driving

[IROCZman15]

absolutely true. that is something I am aware of. with the engine ring gapped for nitrous, and the cam profile, I know that I won't make the 22 inches of vacuum that the booster wants to have. The canister will just hold more vac as a reserve for the brakes, but it wont be 22. the Holley Datalogs (see many previous pages of this thread) are defaulted to MAP and kpa readings instead of vacuum. Doing the math, I know I will fall short. we shall see!

I ordered the tank last night and probably will install it sunday. I will get to try it out a bit and then go to Island on April 3rd to really test it out. Several racers have recommended that I could get a bit more brake vacuum for staging and launching by putting the car in neutral while rolling to the line and giving the engine a few revvs. I might try this too.

[IROCZman15]

Got the vacuum canister installed today. Mounted it under the drivers side inner fender. Used 3/8" hose from the snipers 3/8" vacuum port routed to the 1-way valve at the tank. then 3/8" hose from the tank to the brake booster which also has a 1-way valve. There is a n unused port on the vacuum canister that I put a pipe-plug in to seal it off, but I am considering maybe buying a small vacuum gauge to put in there and then maybe setup my Go-Pro camera nearby so I can see some numbers during street, strip, and autoX driving. maybe. Thoughts?




Took the car out for a good 45 minute drive. Certainly much more consistent brakes. I took a bunch of highway exit ramps where I purposely went heavy and long pumps on the brake pedal and I was able to get a lot more long brake pedal pushes compared to how it used to be. Awesome!

[sweetbmxrider]

If you have a spot, you could run a line inside the car and mount the gauge in there.

[LTb1ow]

Does the sniper not have a MAP sensor?

[IROCZman15]

I actually have an aftermarket vacuum gauge in the dashboard of my Jeep Wrangler. I watch it sometimes while driving, I might do that one day but I don’t yet have an area where I want to put more gauges onto in the camaro. I never wanted the inside of the car to be bombarded with dozens of gauges. If I can do it tastefully , that could be an option.

The sniper's display does have a MAP sensor and Map reading display in kPa. Actually most tuning tables are based off the map sensor. So I can watch it while I drive, BUT that won’t tell me how much inches of vacuum is stored in the tank, it will just show what the engine is making at that moment. Right ? It also measures kPa and not vacuum so I would kinda have to do the calculations in my head while driving? There are conversion charts on Holleys websites, but it would be nice if I could have the display read inches/mercury instead of kPa.

The idea behind the go pro camera would be for me to have a general idea of what the vacuum tank itself retains when I’m coming off of a heavy throttle situation or free-revving the engine. I know it makes 8” at idle, but I’d like to actually see what it makes on deceleration and with a few revvs of the throttle while staging the car? Thoughts ?

[LTb1ow]

Can you change the unit on the display to show inHg?

Can you add on sensors to the sniper?

[IROCZman15]

I've actually searched for exactly that for a while, and never got a clear answer, so the answer must be no. I think the sniper can only display a kPa and a psi reading(in the boost parameter). You have to use "math channels" in the display or something like that to enable it to do its thing. If it could possibly be changed to inches/mercury, I've never seen anyone write up how to do this. Sniper does allow for some inputs into one of the weather pack connectors. Its nothing like what the Holey HP or Dominator can do, this is a base holley setup, so it wasn't designed for lots of add-on's.

[LTb1ow]

If you can add on, I would grab a map sensor to install it on your vac tank. No need for adding guages and you utilize the setup you already have

https://lowdoller-motorsports.com/co...ressure-sensor

[IROCZman15]

yea, thats is a great idea. Glad you mentioned it. I'm not sure, so i am going to check with some of the guys on the Holley EFI forums to see if the sniper can handle this. Would be AWESOME to view the tank's vacuum in real time and to datalog the values and see more info on the logs.

[IROCZman15]

bummer, the Sniper I have is not capable of adding a 5V reference input like what we are discussing. I was told the Holley Super Sniper, Holley X-Flow, and Dominator stuff surely does but I am certainly not financially able to go swapping to a different EFI system this year. For now I might just put that $15 gauge under there and pop my head under the fender at idle and after some revvs. I'll try the GoPro thing, but it will probably shake around to much. if I REALLY need to know, I will consider putting a gauge pod in the car. Might wait until I hook up the nitrous system, because then perhaps I can get creative with a subtle multi-gauge cluster.

Oh well, the can does seem to be working real good. I'll be taking the car to work tomorrow and a drive after. Planning on going to Island Dragway for opening day April 3rd.

[The_Bishop]

Did you install the pump as well, or just the reservoir?

[IROCZman15]

No, just the reservoir. I wanted to see how much of an improvement I have gained with just the tank. If unsatisfied, I can always add the vacuum pump to the system. This I would prefer, as it would cleanup some hoses at the back of the sniper TBI and intake manifold. I would also then have consistent, reliable vacuum, and that vac system (electric vac pump paired with the canister) would be exclusively for the power brake booster only. However, it is just the tank for now and there has been a good improvement. The true test will come from dragstrip and autocross sessions. Thoughts?

[The_Bishop]

You could always use that tank/pump combo to run all the vacuum stuff so that you have a strong reliable vacuum signal to run your interior stuff, and the hoses could be hidden nicely in the fender minimizing engine compartment clutter.

[IROCZman15]

yea, but I have no interior vacuum based stuff. My hvac system went into a landfill about 16 years ago and I gladly never looked back. What else would you be speaking of?


Unrelated: I am really hoping Island is open this Saturday, I know it stated so on their website but they really haven't been updating stuff online much recently ( I know, new baby, legal issues, covid, etc), but are they making us buy admission tickets online the night before the T&T? Do we have to fill out a NHRA covid waiver?

[The_Bishop]

Didn't know you tossed all the HVAC stuff, so I guess that doesn't matter. Whoops.

[IROCZman15]

nah, no worries, I got rid of that stuff so long ago and am glad I did. many reasons for getting rid of it, and only one single reason for keeping it (defog windshield in the rain). Tossed it out and never regretted it.

Anyways, I plan on going to the track for opening day, this Saturday April 3rd. I am going to prep the car on Friday. check/clean spark plugs, pull out front pass seat, swap to the drag wheels, pack tools, fuel up, check tune file, etc. Hoping to run the 11.49 so I can justify putting in the roll bar.

[The_Bishop]

After many, many years of driving stripped down cars I now couldn't imagine not having AC. Was one of the first things I got running 100% in my '98!

[IROCZman15]

Ok, here it goes, been busy every day since Saturday, but finally got the bulk of my post-race day checklist taken care of.

I did go over to Island Dragway for Opening Day which was a daytime Test and Tune event. The weather was chilly, but not too cold. I overheard that Atco did not open today because it was too cold, but I am damn glad that island was open because I had packed and prepped the day before along with buying a ticket and the Covid waiver form the night before also.





Decent turnout of cars. DA was great all day, but there was noticeable wind throughout the day. Gates opened at 10, and racing was 11-4pm. There were at least 4 big oil downs so the track was dead for a bit occasionally. One oil down happened literally the pass before my last pass in my lane, but that one was in the shutdown area, still a long time to cleanup.



The car did good, but not great. I was (and still am) expecting more from the 3.91 gear swap, but I have to figure out what I am doing incorrectly which is not optimizing the gear swap. I basically ran the same type of timeslips that I was running in September and October of last year. 60foot, 8th mile, 1/4 mile and mph was all about the same. Expected a quicker 60 foot for sure, and more mph but did not see it. I did get my best ever 60 foot, but it was only 0.01 second better than 2020. Also a very slight improvement in the ¼ mile with a 11.805 at 116.13 mph compared to my previous best of 11.82 at 115.96. So I am indeed confused as to what needs to be optimized. I know I somehow have to hit the launch harder (without a Transbrake) and I am nailing my shift points…so feel free to chime in as to why/how the gear swap isn’t showing track results yet. On the street, the car pulls noticeably harder in all gears. The gear swap is great on the street, but I did not feel it at the track, and the timeslips verified my seat-of-the-pants opinion also. The converter is flashing higher now with these gears and I am coming through the finish line right at peak HP instead of below it like I had previously been. See my engine dyno sheet on page 1 of this whole thread. Peak tq is at 4,800 and peak hp is at 6,000 rpms.

I made no changes to tire pressure or shocks or suspension all day
- Tire pressure front 37psi on the skinnies 19psi rear on the MT drag radials
- Front struts were left on 1/5 so that’s loose and rear shocks were at a 2/5 slightly loose



Pass 1: 4.5 second mid rpm burnout. Launched at 1,211 rpms via the 2-step. The converter flashed at 3,171 rpm. Shifted 1st-to-2nd at at 6,557 and hit the limiter for a split second., and it dropped to 4,898 rpm in 2nd gear. Shifted 2nd-to-3rd at 6,503 and it dropped to 4,871. Crossed the finish line around 6,198 rpm. 34.8 deg timing at WOT with a 12.7 target AFR.

VIDEO: https://www.youtube.com/watch?v=HFE1ON2GPts








Pass 2: Used the exact same tune file. 6 second burnout at mid rpms. Launched at 1,752 rpm via using the footbrake. Converter flashed at 3,127 rpm. Shifted 1st-to-2nd at 6,504 and it dropped to 4,762. Shifted 2nd-to-3rd at 6,501 and it dropped to 4,907 rpm. Crossed the finish line at 6,223 rpm. Timing was 34.8 and a target afr of 12.7

VIDEO: https://www.youtube.com/watch?v=ZUqr7kcrRkQ









Pass 3: Some slight changes in the tune, I raised the rev limiter and added 0.3 deg of timing. I also applied the learn data to the VE table and it took out a good amount of fuel on the wot part of the table. I was hesitant to do this. Did a 7 second burnout at mid-high rpms. Wanted to try launching off the 2-step at a higher rpm to see what the brakes could hold. Launched at 1,821 with my foot full on the throttle while on the 2 step. Car began to roll through the brakes so I just let it leave. The converter flashed at 3,072rpm, but about 1.5 seconds into the run the engine went soft and I got out of the throttle. Aborted the run but nothing seemed awry on my gauges so I coasted the rest of the pass and looked over the data. Saw a huge lean spike in the datalog and thankfully my 100% open CL comp limits saved my motor from going way lean on me. CL comp went up to almost 90% with adding fuel to correct the lean condition and I am very thankful for that. Still unsure what caused this.. I do need to dig deeper into the datalog, but I wanted to post stuff here first to see if anyone had any ideas. ??


VIDEO: https://www.youtube.com/watch?v=fSljvt9PaAQ













Pass 4: used a different version of the tune from the beginning of the day. 5.5 second mid-rpm burnout. Launched at a 920 idle from the footbrake. Converter flashed at 2,995 rpms. Shifted 1st-to-2nd at 6,573 rpms and it dropped to 4,790. Shifted 2nd-to-3rd at 6,513 rpms and is landed at 4,871 rpms. Crossed the line at 6,172 rpms and timing was at 35.1 deg and a 12.7 target afr.

VIDEO: https://www.youtube.com/watch?v=QH9buNy6DPc










Pass 5: Only changed the timing back down to target 34.8 at wot and raised the target afr from 12.7 to 12.8 at wot. Did a 7 second burnout at 3,500 rpm. Launched the car at 2,142 rpms on the footbrake. I did not expect it to hold at this high rpm, but it seemed to! Converter flashed at 3,075 rpm. Shifted 1st-to-2nd at 66,58 and it dropped to 4,916 rpm in 2nd gear. Shifted 2nd-to-3rd at 6,551 and it dropped to 4,927 rpms. Crossed the line at 6,311 rpms.

VIDEO: https://www.youtube.com/watch?v=z5M338pm-iM






.







Loaded up the car with all my tools, gear, and hit the road home. Drove home with no problems. It was a good day. A good shakedown day after 5 months of no dragstrip passes. Nothing went wrong, just I did not get any timeslips with a 1.5x sixty and an 11.5x e.t., so I have some work to do to hit my goal before venturing into the nitrous realm. I did notice on a few passes that my oil pressure is above what the dash gauge reads. gauge reads to 80 psi and sometimes at WOT the oil pressure is above it, probably like 90. it settles right back down afterwards. this only happened at the end of last year, and everything has been fine. remember my posts about this and my oil analysis and pressure testing with an extra pressure gauge? its still doin it. ??

I am wondering if I need to tighten up the rear suspension a tad. On the return road I heard some suspension parts scuffing, and unless it’s the torque arm hitting the tunnel from my adjustments this winter, I might have the suspension too soft? Maybe the car is squatting too much on the launch? Its hard to tell from just one of Jan’s photos, what I really need is a video. The photo could be taken halfway through the launch’s squat, or at max squat, who knows.




Feel free to comment, suggest stuff, or whatever. Videos, datalogs, photos, are all provided to helm out. Thanks!

[LTb1ow]

I still think that RPM drop on shifts is killing your time.

[IROCZman15]

yea man, I fully agree with ya on that. Ain't nothing I can do to change that. Certainly not going to be opening up the transmission and changing its gearing. car and gearing is now fantastic when driving on the street and i can tell its going to be better for autoX too. Trans is happy and healthy so its staying as is. Converter is also staying the same since a tight converter like this one will be very happy with the nitrous system install this summer/fall.

I gotta dig in and find whats not optimized to let these gears launch the car harder.

[wretched73]

Raise your rev limiter so you stop hitting it. Raise the RPMs you shift at

[IROCZman15]

I raised the rev limiter after the first pass which is the only time I hit the rev limiter. I also was trying to shift at 6,500 after lots of discussion on multiple forums where I posted data and timeslips and other info with the goal of figuring out the best shift points. I had a whole separate thread about this. So what do you suggest I shift at ? And why? I like to hear reasons instead of just blindly doing suggestions. Engine builder said to shift at 6,200 and put the main rev limiter at 6,500. So, I’m already a few hundred rpms beyond his advice.

[wretched73]

Shift higher to keep you in the power band better on the next gear. You won't know if it works until you try it.

[sweetbmxrider]

What rockers are on it?

[wretched73]

Originally Posted by sweetbmxrider

What rockers are on it?

Page 1 has build sheet, shows Crane Energizer rockers-

https://www.summitracing.com/search/...er-rocker-arms

Cam-
https://www.summitracing.com/parts/cca-12-460-8