BUILD THREAD 86 GP 2+2~Blown 6.0

81cutlass

Comic Book Super Hero
Thread starter
Feb 16, 2009
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Western MN
How far are you from the low octane LSA tune, and how far from the high octane tune on the bottom?

Sorry, my ADHD has me forgetting

Low Octane LSA, 5 to 10
1627487791790.png


High Octane LSA 15 to 20
1627487858941.png




The numbers seem to jive with what Happel and Holdener run on their LSA stuff. Happel seems to be on the conservative side of things which I like and Holdener is ragged edge dyno stuff.

Happels 4.8 LSA runs 13-17 on flex, 680 wheel on the terminator setup, but that might have been with spray.

His 4.8 LSA when it had HPT was 10-15 degrees and 570 wheel with 12-14 psi, 80% E, 110F IAT's.

Holdener just posted his 4.8 with a STS-V m122 blower picked up 80hp going from 18 degrees (520hp) on gas to 23 degrees on flex (600hp), but that is VERY controlled conditions with tap water temp heat exchanger temp.
 
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Texas82GP

Just-a-worm
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Apr 3, 2015
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Spring, Texas
I have the same problem, the garage is hot from the day before in the morning.
Not only is it uncomfortable, but it costs you money since you have that really hot or cold space right up against your living space. Dad realized energy efficiency gains just from doing the insulation above the garage ceiling. You're welcome on the motivation.
 
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Northernregal

Sloppy McRodbender
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Oct 24, 2017
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Red Deer AB
Low Octane LSA, 5 to 10
View attachment 180493

High Octane LSA 15 to 20
View attachment 180494



The numbers seem to jive with what Happel and Holdener run on their LSA stuff. Happel seems to be on the conservative side of things which I like and Holdener is ragged edge dyno stuff.

Happels 4.8 LSA runs 13-17 on flex, 680 wheel on the terminator setup, but that might have been with spray.

His 4.8 LSA when it had HPT was 10-15 degrees and 570 wheel with 12-14 psi, 80% E, 110F IAT's.

Holdener just posted his 4.8 with a STS-V m122 blower picked up 80hp going from 18 degrees (520hp) on gas to 23 degrees on flex (600hp), but that is VERY controlled conditions with tap water temp heat exchanger temp.
Now that I'm caught up, 8-14 seems very safe for pump 91, as that should be what the LSA is built for on the high octane tune. If you have 317 heads i would think 23 degrees on top with E is no biggie at 10psi. The LSA has 821 heads and they are a faster burn than 317 and take quite a bit less timing, I have a rod that will confirm this.
 
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Supercharged111

Royal Smart Person
Oct 25, 2019
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Colorado Springs, CO
Oddly enough my place is also a Brick 3 bedroom ranch house built in the 50's. I have the same problem, the garage is hot from the day before in the morning.

I'll take the suggestion and try to get insulation in at least the ceiling this fall. The goal is to keep the garage heater on at about 45-50 all winter this year so my Lathe is a bit more happy. I am going to get eaten alive in gas bill otherwise.

I did put a garage heater in this winter that helped tremendously. Batt insulation in the ceiling is in the plans and I think I am going to try blow in for the walls since they are already finished. Luckily I already have an insulated garage door and replaced the 50's era man doors last fall with some modern insulated steel doors.

Thanks for the motivation :)



With boost?

Both of my Whippled trucks bring the timing in much sooner than stock. I only hit 110kpa here in CO but back in MI they'll get to 140. A PD blower is pretty consistent the way it delivers airflow. I don't really think of it in terms of boost when I'm starting at a map that's defined by absolute pressure. At the end of the day, the only pressure that matters is cylinder pressure. The car still pulls timing based on IAT anyway. You should get to a point where you see knock retard in tenths of a degree up around 1.XX degrees. It should be fairly localized if you're doing global bumps. Just pull it back down some in that general area and continue bumping other areas. The amount of throttle response you gain is impressive by bringing it in sooner. If you come up on it slowly it'll let you know if doesn't want it before it goes kaboom. At least it has for me. When I first put the blower on the dually (with its knock-prone 454 Vortec) I had audible knock in the areas the truck couldn't hit NA. It pulled around 6-9 degrees in the worst spots. I pulled the timing down in those areas and everything's fine now. You're making more boost than I am, but you're also starting with a very safe tune, so super easy to not overshoot it.

Easy fix for that. Fender washers and concrete screws thru the feet with a cordless impact right into the pavement.

Even if you manage to keep it from flying away it'll self destruct out here. Seen it many times.
 
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81cutlass

Comic Book Super Hero
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Feb 16, 2009
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Western MN
Now that I'm caught up, 8-14 seems very safe for pump 91, as that should be what the LSA is built for on the high octane tune. If you have 317 heads i would think 23 degrees on top with E is no biggie at 10psi. The LSA has 821 heads and they are a faster burn than 317 and take quite a bit less timing, I have a rod that will confirm this.

Yeah the more I see the more I realize how low of timing I actually was running. I do have 317's, I didn't know about the burn rate on cathedral port vs. square port stuff.

8-14 does seem pretty reasonable for 91 on a realistic heat soaked setup. I have been digging around on LSA forums and they say 6* of knock retard is pretty common with 140 IAT on the stock tune on 91/93 which puts it essentially RIGHT in that 8-14 range. Max torque at 4200-4600 rpm. 12ish PSI.

General consensus says 20 degrees seems possible if it's cool and on 93 octane, or spraying some alky. That stock LSA 14-20 high octane table does make sense for an engine that is not heat soaked and on 93.

24-26 on E85 seems like the general consensus so another 5 degrees over gas, which kinda aligns with the Holdener gas to E85 test he did where he went from 18 on gas to 23 on E.


I'm going to dial the fuel in on this 8-14 tune and once it's more settled (there are still some holes due to the fuel pressure change when I went to twin pumps) I think I will throw the 2.55 pulley I have on and see what that does to my boost. It should get me to 12-13psi and I will dial the fueling in there. If my IAT's aren't crazy I will look into creating a slightly more aggressive timing table to try at the track. Probably 12-18 degrees and do an A to B comparison at the track to see if I pick up any MPH.



Speaking of IAT's my brain started thinking about building my own interchiller/demon style aftercooler water chiller off my AC.

Long story short, the math on these systems doesn't add up to me. It just seems like a gimmick to me. It seems like it works but once you put a pen to paper they don't. Ice has just shy of 80X the specific heat of water, so if you have 1gallon of ice and melt it that same amount of energy will heat up a gallon of water about 80F.

How did I make that decision?

My current IAT tops out at 140F on a cool, non heat soaked setup with reasonable 60-70F ambient temp. It climbs up to 160F when it is heatsoaked and the ambient temp is 90F+.

The heat exchanger does a good job, I log the temp and it scrubs all the heat out of the system with maybe a 5F temp rise over ambient. The post aftercooler temp rises about 25F, so if it's 65F outside the water temp coming out of the aftercooler is 80F.

I also see about 50F of IAT temp rise compared to whatever is coming out of the aftercooler, so if the post cooler temp is 80F the IAT is about 130F. Heatsoak adds maybe 10F.

My problem is if its 90F outside, my IAT's are going to be 160-165F.

So best case if I can get my water temp down to 40F, I can probably get my IAT's down to 110-120F. I did some math and if the intercooler pump flows 4gpm and I want to keep the water cool for 30 seconds and allow a 10F temp rise (40 to 50F), I need ~2megaJoules of energy stored in the water.

The problem is that is 12 gallons of water. The blower puts out enough heat that in 30 seconds to heat 12 gallons of water from 40F to 50F. Even if I would only want to cool the air for 15 seconds (2-4 seconds to cool-soak the aftercooler post burnout plus the 10-11 second run that would still be 6 gallons of water and I don't want a 5 gallon bucket reservoir hiding under the inner fender of the car.

If I were to put an ice tank in I would need about 13 pounds of ice per run, or basically 2 gallons of ice, so I would need a 5 gallon tank in the trunk and drain 2 gallons of water every pass to add more ice. Granted my IAT's would always stay at whatever rise over 32F, but still. The math is starting to make sense on why people burn so much ice per pass if they have an ice tank.

So I am just going to live with 160F IAT's and heat soak! The amount of cool water I need in a reservoir too much to make an interchiller system work.

Automotive AC systems are 20k BTU/hr at max, so to cool my warm 50F water to 40F to scrub the 2MJ of energy the blower added for the 15 seconds, I would need to run my AC pump for 6 minutes.

Running the AC pump during the pass makes zero sense also. It only puts out 5BTU/sec best case which is 0.005MJ/sec. Ouch. The blower makes 133MJ/sec of heat according to my sensors.


So no interchillers for me!
 
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64nailhead

Goat Herder
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Dec 1, 2014
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Upstate NY
160 isn't the end of the world of you can pull a couple of degrees from your 140 timing.

I've seen a little bit higher than that lol, okay, maybe alot, but I'm hoping that is resolved as of last night.
 
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Northernregal

Sloppy McRodbender
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Oct 24, 2017
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Red Deer AB
160 isn't the end of the world of you can pull a couple of degrees from your 140 timing.

I've seen a little bit higher than that lol, okay, maybe alot, but I'm hoping that is resolved as of last night.


Your IAT sensor as Holley just adds more sauce during the run....

Fire Thumbs Up GIF
 
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Supercharged111

Royal Smart Person
Oct 25, 2019
2,433
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Colorado Springs, CO
I saw mid 150 in my flipper dually which is NA! I wouldn't lose any sleep over 160. My trucks run at least 180 , that number I have seen. Worst case maybe 200? Unintercooled of course. I want to say at 14psi my Corolla in Okinawa ran about 175 with an intercooler on a hot night. That was more sustained boost than a drag run though.
 
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81cutlass

Comic Book Super Hero
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Feb 16, 2009
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Western MN
Well I took a long weekend roadtrip so I was off this car for the last few days.

Dropped a router table part off a shelf onto my foot last Wednesday and could barely walk for 2 days (probably sprained my toe) and didn't have the strength to even push an accelerator pedal so no timing test pulls for a few days. Waiting for the nail to ejecto seato cuz.

Decided the best way to get over it was go vacationing in the Black Hills so drove to western SD. Lucky we took the wife's Fusion (didn't let her drive most of the way because she drives slow and it bothers me lol) so I can set the cruise to 84mph and not touch the brakes or gas for 5 hours. Have I ever talked about my love for SD lol. Cheap gas, 80mph interstate speed limits.

There is a auto resto shop/junk dealer out there (actually the one Derek from VGG used to work at and does some videos at) and swung by to see what their inventory looked like. Always in the search for a buildable 73/4 Omega hatch.

Found a 74 not hatch but it went through hail. Hood and trunk are gone but I can get decent ones from my local salvage yard hookup. Would be a moderately OK starter for a 8.50 drag build but I don't need it today so I'll lock it in my notes and address at a later date.
1628045313999.png


Ironically Derek and family were hosting their yearly car show (totally unintentional I stopped by the day they had it) so it was pretty packed.
1628045678477.png


1628045791271.png

1628046277258.png



In progress news-

I registered for HR Power Tour. Probably make 2-3 stops. Got a little work I want to get done for the car before then. Change oil, get a spare fuel filter, try to figure out the AC idle bump function in the PCM.

Happel posted an LSA tune on a ly6 last week that was tuned to run on 87 but add timing with flex. He was running 8-12 degrees on 87 with 6psi and added 6 degrees with 50% ethanol intro. Exactly what I want my tune to do.

I added the timing into my low octane table to get me to 8-12 base on gas and then plugged a goal of 6 degrees into my flex adder. I also pulled my IAT retard back a bit. It was starting at 140 so I bumped it to start at 160. My goal is to hit 14-18 in flex at the track and then trickle in 1-3 degrees and see how the RPM behaves.

I planned to take a test pull tonight but my battery was low and the car didn't start. I'll have data tomorrow.
 
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81cutlass

Comic Book Super Hero
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Feb 16, 2009
3,524
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Western MN
Older picture of the 2+2 from '18 drag weekend popped up (the first time I blew my rear axle lol) and raised the question, should I go back to the tool box and tire caddy on the trailer hitch or keep with storing the tires in the back seat.

I bottomed out HARD when I did this with the stock springs in '18 but it was really convenient to keep all my tools locked up and tires outside the car. It made loading and unloading the car much easier. The caddy has some fold down legs so I just pull into the spot at the track, fold the legs down, pull the hitch pin and pull forward. Putting gas on was kinda a PITA.

I have 5409 rear springs now and spring seat height adjusters so the car shouldn't bottom out like it used to so roading should be more pleasant.

However, I found totes that fit into my trunk so I can get all my tools into the trunk. Sliding the tires into the back seat is a pain however.

Options!

1628090702849.png
 
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