TURBO TUNING-PUMP GAS VS RACE GAS Full Dyno Results

[@SloppyMechanics]

4.8 and s475, this is the way

[@jaredfarney675]

😯🏁😎

[@turbolq4]

So sayeth the Lord

[@timothybolden9955]

turbolq4 🤣🤣🤣

[@mxguy2438]

Best video yet. Excellent dense format, real data, real tech, reasonable length, good editing, good audio nothing annoying. You've got a brand here Richard. Keep it up. Have a great holiday and thanks!

[@dontrudeau9362]

100% agreed!

[@richardholdener1727]

thnx

[@legros731]

Lol the audio is terrible like all is video can barrely ear is voice on Phone

[@mxguy2438]

@@legros731 there is like 30 seconds in the beginning where he is in the dyno cell where its weak but still okish, but the rest is fine on my systems.

[@martinrodger9565]

Also 100% agree. Zero filler, all killer info with clear conclusions on set changes acknowledging other variables.

[@BlindBatG34]

Wow Richard, just wow. That was like watching a mini version of Engine Masters with more technical content in less time. I can now see why the cult of E85 is so devout. I wish I could give this video two thumbs up.

[@TheProchargedmopar]

BlindBatG34 You can, 👍👍

[@buiItnotbought]

Maybe give it 3

[@81eagle]

I wish I could find E85

[@SweatyFatGuy]

@@81eagle If you live in the states, go here put in your city and state, and it will tell you where it is and sometimes how much $$ e85prices.com I daily drive 455s on E85 that have 'race gas only' compression between 11:1 and 13:1, its so easy and man does it run good.

[@81eagle]

@@SweatyFatGuy Thanks for the link. Looks like there's some 70mi from me. I'll have to call to be sure.

[@DrewJZ]

E85 often hides detonation and the dyno is a great indicator of this. So I agree with you that relying on a knock sensor is not a good method. I'm also glad that you mentioned where you should pull timing (pk torque which is also peak cylinder pressure). That is how you keep rods from bending amongst other components. Also, a good way to tell that you're maxxed out on timing is when timing stops making power. If 1* only makes a few hp rather than ~15-20hp, you're done. Back it down. Good tuners will also know how to introduce cylinder pressure (timing ramp). An ugly timing map that isn't smooth will literally cause turbulence in the combustion chamber. However, a smooth transition of timing from peak torque to max rpm can get you better and safer results. I would go into how to read spark plugs as an indicator but I could elaborate for days. Maybe a good idea for another video?

[@baby-sharkgto4902]

Yes I would love a video on reading spark plugs!

[@DodgyBrothersEngineering]

DrewJ_Z care to elaborate on how E85 "hides" knock? Knock should be knock. E85 has a much higher RON value, which by it's very nature means it will take more timing before it knocks, but how do you think it hides it? Either it is knocking, or it isn't. A set of knock ears should pick it up regardless.

[@Rajivc666]

@@DodgyBrothersEngineering guess what he meant is that on e85 sometimes you can increase timing over MBT and still not knock, which makes knock based tuning not very ideal for e85.

[@DodgyBrothersEngineering]

@@Rajivc666 ahhh yeah that makes sense.

[@fastinradfordable]

Also can’t rely on knock sensors on a ls because they fill with rain water and corrode.

[@juicyjuice3282]

Old video but I’d also like to see the timing curve and more explanation on where to ramp timing in/take away. Thanks for this priceless knowledge you provide 🤘🏻

[@fbanda20]

I love great info in the morning as I drink my coffee ☕️.

[@chrisjamieson1285]

I learn something pretty much every time I watch your videos. Thanks for all of your hard work!

[@TR99FRC]

Perfect length of time for videos. Excellent knowledge and information. Keep them coming sir!

[@eros20V]

Excellent presentation . Repetition of key facts is key for adult learning :)

[@ezelk1337]

Some of the best explanations of how to make Horsepower and torque on KZbin! You should be at 100K subscribers by now. Keep up the great work. I'll be watching.

[@fc3sluis]

Great info. Love the detail and showing the timing difference, afrs, and boost. Gotta love the Holley closed loop tuning too shows what a good job it does keeping target afrs

[@richardholdener1727]

Thnx, but we didn't run closed loop-we ran open loop with no change in the amount of fuel supplied at each timing level

[@smallmouthfreaks7609]

That is an incredible difference. This video just changed my mind about running pump gas. I have no E85 pumps near me, but for over 100hp difference, I'll go find some

[@simonaragon6590]

Great video , I absolutely loved it This is one of the videos where I’ve learned the most and I easily understand it .someone with very little knowledge on engine can understand it because u break it down so easy for someone to understand

[@FirstLast-bi8xi]

Egt would have been good to see

[@Klumpi84]

Please Richard Holdener let us know the EGTs!

[@sbc350]

I'd like to see that too

[@james10739]

Ya seems like it would change

[@JayBeezy31]

im also curious, but we use egt to get an alcohol tune close, then fine tune w timing, but yes i am also curious guys lol.

[@timothybolden9955]

Why would that matter if it’s not running lean?

[@fasteddy]

Show us your timing curve Richard, love what you do thanks

[@cammykakes5420]

This was an excellent technical vid

[@flatbrokemodsquad4241]

great video Richard! I like how you explained each graph. I'm making the jump to E85 for my project even though the nearest distributor is 20 mile away.

[@finnroen2334]

This was good. Boosted engines need timing on pump gas too and this is why lower compression ratio is way more effective on pump gas than most people seems to think. A low compression ratio engine with the same or more boost, and 20 degrees of timing would be interesting. The ratio between peak cylinder pressure and BMEP gets better too. :)

[@jimhopps2359]

I would like to see pump gas like 92oct with 8.5-1 to a 10-1 motor. As stated the More timing you can run might be better with pump gas. Equal to equal it's hard but two motors with different pistons and different timing to see what's better.

[@DaOnE51T]

Great content sir. I have learned timing is everything. Too little timing=not enough power too much timing=broken motor. You have to sneak it in. I always start conservative with pump gas. I always think of it as the final touch in the tune, kind of like the final condiment in cooking! Lol

[@brandonpanozzo86]

Early morning turbo information hell yeah richard you are the man

[@mattvorhees6055]

These videos are very helpful. I'm new to the turbo scene so I come here to learn. I'm gonna do a single on a 5.7 hemi so more hemi content would be great.

[@richardholdener1727]

did you see the hemi turbo video?

[@baby-sharkgto4902]

I'm absolutely loving all of these videos!

[@halfbakedcoatingsllc9911]

I was running 20 degrees of timing at 10lbs of boost on SBC with 93 octane with no issues I'm a member of the blow through mob on Facebook. Lots of guys running even more boost than that with pump gas

[@richardholdener1727]

at the hp peak i'm sure and on a sbc-that wants 36 degrees na

[@ToprankImporters]

Great video. Sound is much better with the lav. I am now a member of the Cult of E85. Smells great, awesome for a turbo car.

[@mikemaccracken3112]

Great video Richard.

[@00infernoGT]

air:fuel describes a measurement of fuel and air in the cylinder. Changing the point at which you light that mixture will not change the ratio that was already inside the cylinder to start with. you can have 0 or 30 degrees and there wont be any difference until the mixture fails to light and burn completely. once you see the engine failing to burn the fuel, you will start to get different readings. In some instances you can find the sensor showing extremely rich, past that it will start to go extremely "lean". This doesnt mean the engine is necessarily running lean, but you're looking at an oxygen sensor. If the fuel didnt burn, the oxygen wasnt used and it will be present in the exhaust when it passes by the sensor.

[@supercharged6771]

You are a pioneer my friend, I've had a roots for about ten years and getting hard numbers has been difficult, lots of talk but slippery when it comes to numbers... keep up the great content. Get some exhaust numbers to mix with with the timing

[@richardholdener1727]

i did the timing test on a number of other combos including a Whipple supercharged 4.8L

[@TrojanHorse1959]

Merry Christmas & Happy New Year Richard & Family! Merry Christmas & Happy New Year to everyone else too!

[@richardholdener1727]

you to and to all

[@Turbogto_guy]

Holy shit! I’d be interested in seeing if pump gas would make a different power at at lower timing because the burn rates of two different fuels will burn differently.

[@rebel4life383]

theoretically it should be the same but the timing changes would be further down on the graph I'd assume. peak being around 12* like he mentioned. I'd be interested in the same vid and motor using 93 pump as well

[@MLFranklin]

Flame speed isn't that different for most hydrocarbons. The bigger difference is the resistance to knock.

[@tsiawdspyder]

Great video richard. Only thing I think you could do differently would be mess with the sounch quality. Some parts of the video I can hardly hear you talking while other parts are really loud. But definitely keep the great videos coming. Very helpful and educational.

[@ryanaxberg9263]

I really like the video!! Perfect blend of everything. Also great test, keep it up Richard

[@HiShBL2]

I understand that what you did was an illustration of timing vs power , but in fact a pump fuel acts differently than e85 , meaning on 12 degrees of timing both fuels would have different results .

[@TheRcbthree]

agreed, i think this would provide much more info.

[@calvinevans8305]

Low octane expands quicker, burns faster right?

[@frenchonion4595]

I know it drives freaking nuts that he refuses to run 91 pump for some odd reason even the engine masters guys beat around the bush. One episode they said they would test 91 on a turbo 5.3 build but they beat around the bush too and ran 114 race fuel. It's like they are scared to tune it because it might scatter. Its honestly kinda weird and you're right about that. There's guys making big power on pump

[@sambo92]

Fuel to air is about thermal management, not necessarily power. Timing is where the power comes from.

[@johnparrish9215]

Mr. Holdener, Some day, if you have time or interest, could you do a test of Water/Meth (75/25) injection and it's relationship to ignition timing?? It could be interesting

[@chipturd55]

Won't

[@beaugouin4383]

loving the channel dude! all of it! still have the origional big bang edition magazine! even better now! cant get enough!

[@oklifrederick1734]

The afr didn't change bc the engine is still burning all the fuel just closer to tdc

[@tptrsn]

One of your best videos Richard, thank you!!! Ask and ye shall receive on the Richard Holdener channel. Lol (seems like I asked for something like this video yesterday?)

[@richardholdener1727]

merry x mas

[@davemackinnon6487]

Um? How is this a test of race fuel versus pump gas? It’s a demonstration of how timing affects power. Does E85 burn at the same rate as pump gas? I doubt it. I’d have much preferred to see you actually change the fuel.

[@adamloveshondas3122]

Great info some people don’t get it if you explain it to them it’s like they can’t wrap there head around the idea that the piston speed will out run the spark witch causes loss of power you want it to spark shot 12 degrees after top dead center just when the piston it’s starting to fall😂😂it’s was supper cool to see the effects on paper

[@divafizz]

Thank you Richard.

[@johnrodabaugh4887]

Loving the new longer videos!

[@Chasemanuti]

Like the longer formats!👍

[@alexrozier6550]

These are awesome videos man. Keep them coming.

[@brianwiniarski4490]

Bad ass video like usual! Would like to see the difference in the spark plug strap color vs timing change. Like is 20* near the bottom, 16* at the bend, 12* before the bend etc.

[@michaelblackmon5010]

E85=pump gas? Not in the Southeast sir. put that 347 with the 174 Weiand on the dyno and tune it to live on 91 octane. down here E85 is only had at the dragstrip right beside the "race fuel". let's compare 91 timing to e85 and let's see the max tune/ hp on both. keep up the good work Mr Holdner. love your channel.

[@bebetekracing2412]

Great video Richard.. Love the channel. Just please do something about the volume. Most of ur videos are recorded low volume. 👌👌

[@dumpsterrentalservices2602]

Agreed on getting a mic

[@richardholdener1727]

was it just the section in the dyno cell indicated at iphone?

[@dumpsterrentalservices2602]

Love the videos man. Just have to turn up the volume then itll get loud all of sudden. I think it's when your further from the camera so a mic should help.

[@drakeolson2539]

Man, great content again!!! Really learned a lot on this one!! Keep up the great work!!! Thank you!!!

[@wymansst]

New subscriber. Enjoying watching and learning from your videos. Keep up the great content.!

[@hillbillydeluxe08]

Should do a mild big block build to see what the limits are of the blocks being gen4. 2bolt vs 4 bolt. Arp bolts ect. Budget crank and middle of the road rods. Stock caps and maybe a girdle and see what a guy could do out of his garage on a turbo big block without hurting it. Thanks for the vids!

[@hillbillydeluxe08]

Maybe even a stock bottom end deal

[@TurboDog73TX]

He has done a few big block / turbo vids. IIRC, He has even done a "big bang' BBC build a while back, but I don't know if He's ever posted the results.

[@hillbillydeluxe08]

@@TurboDog73TX I seen the nitrous one and the turbo one but who runs stock heads? Atleast a chinese top end and a decent bump stick is what most would run. Would love to see how much it could do being the turbo has less stress on the guts then the nitrous. People talk about the blocks breaking around 1k or 1100hp. But do they really when done with a slightly educated approach. Girdle, gaskets, arp bolts, good tuning ect

[@richardholdener1727]

already took a stock Gen 6 bottom end with ring gap to nearly 1300 hp-there is more left

[@TurboDog73TX]

@@richardholdener1727 Richard, is there a link to that vid? I know I pestered You forever on FB and I still don't recall seeing the vid of the 1300hp BBC. Thanks man

[@ARK842001]

It would be interesting to see how water/meth would change the values both in throttle body injection and port injection, and maybe in the turbo inlet also.

[@babyruuth]

Pump and W/M testing would be awesome!

[@nitrousshovelhead]

best video yet. thank you and keep up the good work

[@eliascorteslopez1094]

Awesome test Richard, thanks for what you do.🙂

[@workhard6445]

Awesome information that back in 90s was top secret no Internet or KZbin 😂

[@3800TURBO]

Richard when you get a chance test E98. Test it at richer than normal levels with higher output ignition. I found you can add fuel and timing and keep increasing power as long as you can light the heavy mixture.

[@danielsullivan9865]

What timing boost and AFR so you running on E 98

[@414Chevy]

The A/F thing really threw me off. Didn't expect that. Next test: Pump 93 w/H2O Meth vs E85. I'm lazy and don't like adding a lot of electronics and fuel system stuff, when I can just use water/meth. If it's good enough for a Focke-Wulf FW-190, then...…..

[@MichaelWilliams-wo7yw]

I learned something today, thanks.

[@andriosz]

Same test, but comparing 87 to 93 and to E85 :) I like my gas cheap in my daily driver :)

[@321-Gone]

I like the information heavy comment. No hype just info. You are great at explaining tuning. I think you might be the guy to explain building a tune from scratch using MPH on the time slip. Not allot of content on that told in a clear way. It'd be interesting to see this same test but with a manual boost controller with no correction. As a follow up to this one.

[@derekwoods8199]

That was a good breakdown.

[@byronboost]

love your videos

[@thomasfleming1121]

Would love to see a 91 pump gas-water/meth test, on stock LS intake would have to use port injection being as in engine masters the ls intake doesn’t wet flow water/meth very well.

[@chipturd55]

I've asked

[@Sands10welding]

Love your videos but do something about the extremely low volume please!

[@Nate-oh1wg]

No afr change because the timing change is optimizing the timing/event of the burn. Not affecting the amount of fuel burnt.

[@joshdrobny93]

If your afr is not set up correctly, and you change timing, it will give the illusion that you need to change them together. Many people don't understand this.

[@pyric]

One point that is relevant to the discussion but not to this test is different fuels have different properties that will also effect detonation & hp. Leaded race fuels may have oxygen added that improves hp output. Also E85 & Methanol have cooling properties that also add hp & combat detonation. It would be interesting to see tests finding knock limits of pump gas and what differences spraying meth or mixing ethanol would do to it.... but would be harder to test. Awesome test though people don't understand timing well enough.

[@ryanboytim896]

Changing timing doesn't affect AFR because you're not changing fuel delivery at all just changing the position of the piston when combustion happens. Better rod angle on the crank, more cylinder pressure means more push but that doesn't correlate to fueling

[@richardholdener1727]

Thnx for watching til the end

[@ryanboytim896]

Richard Holdener hahah I commented and then seen your explanation. Great video!

[@ryanaxberg9263]

nothing changed on the afr because the same amount of fuel and air were in each cylinder on each test. Timing just made higher cylinder pressure and as a result more powa

[@drivinwithdrew7676]

Sweet video! Great test 👍

[@kevinkalivoda3442]

I was expecting more discussion of pre ignition due to fuel octane not just timing adjustment for detonation. Because race fuel (e85) was used for the entire test I would think the outcome might be different if 91 octane gasoline was used during the lower timing runs since higher octane fuel needs higher heat to burn properly. But maybe my teachings are incorrect.

[@oldudesrule]

But you didn't use pump gas ??

[@plumbs7199]

Very informative, thank you !

[@johnthefisherman6090]

Very very good stuff man

[@xozindustries7451]

Air fuel ratio doesn't take into account where the spark occurs in the engines cycle, there is still the same amount of air and fuel in the cylinder

[@brianmathew09]

I so miss the days we could go to the local airport and get aviation 112..good fuel is crazy $ now.

[@SteveFuentesRacing]

These are really really good videos

[@TheDward0909]

Richard, love love love your channel and thank you for all the time and work you put in to these tests for us to learn and understand. Can you add the differences of hp, torque to the videos (as txt)? Would super helpful! To visually see the “diff +80hp, diff -60tq...” maybe at both peak and avg? Just a suggestion. Again thank you so much. Your knowledge is extremely valuable!

[@SoGoodRc1]

Richard its a great test !!! We need the same test using meth injection over better fuel, lot of us have a hard time tuning with it maybe something to look into. Literally the same test just increase the meth with timing see if itll go 20°. Awesome work nevertheless great explination of piston position and reaction.

[@richardholdener1727]

water meth has less than ideal distribution in these long-runner intakes

[@artcampbell5315]

yay! i can read the numbers on the graph this time!

[@douggreen1105]

Would love to see this on 91-93 octane,,E85 isn’t available where I live.

[@danielsullivan9865]

Great comparison looks like volumetric efficiency was around 104 at 6300 RPM's went to 84 on 12 degrees of timing. The loss and volumetric efficiency was almost exactly the same as the lost in Porsche Power. About 20%. I bet that little engine could have taken a little more timing possibly bringing the volumetric efficiency up to 107 or 108

[@mxguy2438]

There is no difference in VE between these runs. He did a good job of controlling the variables and showed that he controlled both boost and fueling... so we know the torque differences between the runs is purely from changing the timing.

[@soundslikealot]

Would like to see/listen some more tuning secrets and just information from you on this topic 👏

[@richardholdener1727]

send me some questions-happy to help if i can

[@MrTommy954rr]

Just wondering - wouldn’t the burn rate of say pump 93 compared to E85 or race fuel be a major difference in power output and the correct timing for each of the burn rates?

[@realtuners707]

Pump 93 has the most BTU per gallon, thus will make the most power *if* the engine isn't detonation limited, which under boost - an LS becomes that. What he's doing here is showing you what the difference in safe tunes for both will do to power. But IAT is a huge factor as well. You can go really far on pump gas with super low IATs and high quality, gulf coast refined pump gas IMO

[@richardholdener1727]

I have never seen 93 (or any other gas) make more power than E85 on a turbo motor unless you change another variable like boost or timing

[@realtuners707]

I believe that. We all form out opinions on our experience.

[@realtuners707]

@@richardholdener1727 When you change the fuel, or any other number of variables, you ARE changing the timing. Timing is "when peak cylinder pressure is reached, in reference to crank angle." You should see if someone will donate a combustion pressure analyzer for your testing. That way you can always adjust timing so that peak pressure happens 12-15* ATDC (which is where peak torque always happens, in pretty much every engine out there). and that would help you keep the tests more consistent. Leaving the timing in one place is actually causing inconsistencies in testing.

[@fastinradfordable]

Real Tuners Mind blown

[@claypaul2012]

I prefer the short concise videos and I can see where it would be beneficial to do an in-depth video on a topic.

[@BlindBatG34]

I can definitely see where you are coming from but man there was so much good stuff in this video.

[@claypaul2012]

@@BlindBatG34 I would consider this video the short concise type.

[@mxguy2438]

I think the 2 minute videos are too short, they leave important details out, and info flashes on the screen so fast, you spend a bunch of time going back to digest it. 5-15 minutes is a good length for me as long as its dense, pertinent info like this... Of course, shorter is better up to the point where the info is hard to process or things get left out.

[@RHYNOMAN12]

Awesome channel!! Richard please read. 2 things I’ve been curious about testing, 1. supercharger setup through headers which are 8 to 1. Curious if the exhaust gasses will raise TQ further with 8 to 1 exhaust pulses. Using exhaust pulses in the 8-1 to rotate out the gasses out. Also the exhaust note should be nice. (LQ4 with whipple 2300) 2. Single Turbo setup (T6) with twin scroll using 4 to 1 collector per scroll. Will using the rotating pulse into turbo improve the spool up? Will this reduce lag? What size waste gates will this require?

[@46kvolt]

Richard, I have just started a LY6 swap, I am really just going to clean up the motor except for a cam swap and maybe springs. Can you do a video on VVT and if it helps at all with tuning and power or to get rid of it. I would like to know before I make that cam purchase! Thanks, live the channel!

[@simpleman2004]

Watch his other videos, He gets rid of it on most of the videos I've seen.

[@46kvolt]

Simple Man I scrolled through all the titles but didn’t see anything about VVT

[@simpleman2004]

He probably doesn't have any specific on VVT. Just on the cam swaps in the engines that have VVT, he removes the VVT. Thats what I should have said.

[@harperjmichael]

I've gotta fever, and the only cure is more hand gestures.

[@richardholdener1727]

you should be cured by now

[@Parents_of_Twins]

I would like to see a similar test run with pump gas Vs race gas. I wonder about the difference between ethanol/gas mix of E85 versus 93 octane gas the difference between how they combust. It seems to me that there should be a difference there in the combustion rate and that should change the amount of timing as well. I think it would make an interesting test. Also 20 degrees for max timing seems low what about testing an engine that is capable of taking more timing 30-35 degrees for max. I think the overall results would be similar but perhaps not. As a scientist (Chemist) and engine enthusiast I really love this channel, keep up the good work.

[@ericperry4934]

How to tune my ecu. Which compression ratio to use. What is a redline tune. What to adjust. 1000+hp goal Lq9 4 .000 / with +29cc forged dish pistons Gen 4 rods and arp bolt L92 heads stock 70cc Comp cam 239/255 @.50 624/624 114 Boost 24 psi turbos 66mm twin Rpm 6500 E85 18* spark Arp head studs. 1200 cc injectors. Ls3 intake. 4l80e 3800 stall .32 top/.30 2nd. .70 oil gaps STATIC Compression Ratio: 7.73:1 DYNAMIC Compression Ratio: 4.87:1

[@dennisclanton5342]

great vid! Thanks

[@calvinevans8305]

I can't buy e85 at the pump where I live, lame.

[@chipturd55]

That's what I told him

[@chipturd55]

Tried to say. E85 is not real pump gas. Yu can't go anywhere and get it

[@DodgyBrothersEngineering]

Richard you've got me scratching my head a bit on this one... I'm not completely sure by what you mean when you say 12 or 20 degrees. Are you just setting the initial (some call it base) timing to 20 degrees and carrying that all the way through the map? or are you doing something different below 4000 and setting it to 20 degrees above 4000? Would love to see you do a full video on just tuning, especially on turbos. Actually would be nice to see what you change between turbo and N/A.

[@geoh7349]

Id like to see you run smaller turbos that spool sooner

[@fastinradfordable]

George Hitchborn Same.

[@user-tc2hu1mr3k]

Also as soon as you leave state e85 gets hard to find as a daily driver. 91 everywhere.

[@rocketsurgeon11]

So, if you monitor EGT you will see exactly why the AFR didn't change, but power did. I would like to see a correlation between maximum power and EGT on pump gas versus race gas. Specifically using the different fuels, not just detuning a singular fuel.

[@richardholdener1727]

EGTs can be altered by a number of things other than power, including timing. We can't run 20 degrees on pump gas and as indicated, we didn't tune using knock sensors.

[@TurboMalibuV6]

Oh Lord! Now those guys that think *bigger is better* is gonna take the timing to 30; to try to get 100 more HP over 20 degrees of timing and start blowing head gaskets.

[@nsboost]

Getting timing right just increases the efficiency. Your taking what is basically the same burn.. but using it more efficiently by moving when it happens Edit: Shoulda watched to the end and seen that you explain this 😅

[@richardholdener1727]

always watch til the end, yo!

[@PANTYEATR1]

The AFR didn't change cause the same amount of fuel is in the cylinder and the valves are closed. The ignition was fired at different times while the valves were closed. Is ignition timing tuning easier or harder for an N/A engine? Where do you start?

[@richardholdener1727]

EASIER-LESS SCARY

[@Kj16V]

I was really surprised by the fact the AFR didn't change with such a wild swing in timing. I know, from my own experience of tuning engines, that retarding ignition usually makes the AFR go richer. Because the fuel has less time to burn completely. I'm really interested to know why that didn't happen here. I've never tuned with E85, just 93 and 95 octane. I wonder if the high ethanol content is what makes the difference?

[@richardholdener1727]

timing changes don't usually change AF much-your tuning might be allowing changes of the fuel delivery with timing

[@gregdavis3324]

Great video, a couple of thoughts. 1. Did the EFI system utilize wideband O2 sensors? This coupled with the use of electronically controlled wastegates could have played a roll in the reason the AFR stayed relatively the same, pull after pull. 2. I would have liked to see the EGT's for the race tune Vs the pump gas tune.