IHADAV8.com - Turbo Buick Tech, and Nonsense
Tech Area => General Buick Tech => Topic started by: Tim Hensley on June 19 2019, 04:28:28 PM
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I made five passes last Sunday
My mph first pass was 118.5
Next was 117.9
All the way down to 117.2 last pass each pass got slower.
It’s the intercooler getting hot right
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Or the air going to crap.
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I’m probably over thinking it. For 1 mph. Should I take my leaf blower?
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how long between passes? what was the ambient temp doing? Are you spraying alky?
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30 minutes on one set 45 minutes to a hour the rest
85 degrees and spraying Alky
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If your 60 ft and the 1/8th times are going the same direction, in the same proportion, it probably isn't the car.
In the quarter, you are talking maybe 5 hp average for the run. The difference in rollout can be .15 sec at full throttle. Bracket racers could name a dozen things.
Head/tail wind, coolant temp consistent, etc. Most bracket racers never stop practicing their leave and their times will vary 1mph in an eighth.
You are making enough steam to go 118/quarter. Get some seat time/enjoyment. There will plenty of time to worry.
JMO.
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You are not what I call hot lapping and I suspect that is not what caused you to slow down. I am not a fan of hot lapping. Not because of the I.C. temp, but, because you can cook the oil pretty quick if you don't let it drop back down. That's hard on parts.
Particularly when spraying alky, I notice that some of the guys that actually measure temps and such stuff are beginning to go back to stock location intercoolers and are still knocking on the door to the 8's. I'm sure those guys are blowing air across the core after the run to remove some of the heat faster but I have not asked that question. I have seen a couple with fans added to them which are run after the run.
The hardest concept for many is to understand that when you make an 8-11 second run, the intercooler does not do significant cooling from air flow. It might do some cooling if you are road racing or such under continuous throttle, but, in a drag race, it's not worth worrying about.
Basically, an intercooler is a heat sink. It may look like a radiator, but the tubes are not made like a radiator tube. Lack of pressure drop is far more important than cooling from airflow. Alky more than makes up for any supposed lack of temp drop. The trick is to cool the core back down before the next run so one is always running on the same baseline.
I saw someone's ic on FB the other day and it was positioned parallel to the ground with a fan on it that activated after the run.
Heat Sink-it absorbs and carries heat to the fins and in 8-11 seconds, that needs no real time air flow.
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Quaker City- FWIW We did note some guys running generators to power fans blowing into the grill. And because Steve had already explained it to me I could sound smart to the Mrs :)
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Ricers used to spray CO2 on them to get them really chilly, really quickly...sure stresses the structure in a hurry.
Dave, did you see that discussion on FB where Ortofski, or however he spells it, stated he ran the same temps and same times when he stuffed a blanket in the air intake to block air flow as he did without it? LOL, The crowd went wild calling him an idiot. I did not recognize any names in the mob and I suspect most of them still believe what their favorite internet vendor tells them.
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Kinda goes back to this....
http://www.autospeed.com/cms/article.html?&A=110772
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I was working on my 60 time,each pass I added timing 129-130-131 to the TT chip, nice and slow looking for KR and WB 1/8 mile mph stayed at 93.1-.5
60 and 1/8 ET and 1/4 ET improved from
1st pass. 11.612 @118.33 60ft 1.799
Last pass 11.556 @117.13 60ft 1.687
Not great improvement but improvement
Trying to get data on converter it could be loosened up on the bottom and tighten on top just a little ,but it’s street manners are so good I don’t want to mess that up.
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I was working on my 60 time,each pass I added timing 129-130-131 to the TT chip, nice and slow looking for KR and WB 1/8 mile mph stayed at 93.1-.5
60 and 1/8 ET and 1/4 ET improved from
1st pass. 11.612 @118.33 60ft 1.799
Last pass 11.556 @117.13 60ft 1.687
Yup.
You should expect the mph to drop further tenths as the ET drops. The only way to improve both is to make more power. You are using the same power more efficiently. At that size car, I would consider 1.6x shorts to be pretty good.
Congrats on a mid 11 sec street car.
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Earl, I don't think I have seen that particular article before. It sums it up nicely altho' I am sure that 90% will want to argue about what color to paint the intercooler to make it cool better.
I think I will save the candles after my next seance. :tongue
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Tim, For 93 octane plus alky spray, my experience is that in low gear, one wants to run more timing to spool the turbo and get the alky to make some heat which translates to power. This can really help when the converter might be a hair tight for optimum performance on the bottom end.
Short times are everything. On a moderate cars like yours, we see that one tenth on the short time often translates to 1.5 tenths at the other end in the quarter. If we get more serious and start running into the tens, then that tenth may become two tenths on the top end.
To improve on short times, it takes more power and the ability to stick it to the ground. In other words, you spin, you lose. Experience tells us that a 1.6 short time is usually not too hard to achieve on a turbo Buick if the engine is healthy and the converter matches the turbo with sticky tires and a rear suspension that is fairly healthy in factory form.
If that is so, then the limiting factor is how much boost we can hit the rear tires with before they spin. I recall guys that were putting fiberglass on the front end and bags of cement in the trunk to be able to leave harder without spinning. :chin:
The basic problem with G-Bodies is poor geometry in the rear. Often the instant center is located up near the front wheels and the car does not want to load the rear tires on launch. Add a little too much boost and the car does not want to leave the line because the back tires are blown away. To go a lot faster/quicker, one must do something about that.
Anyway, again with alky and 93, use timing in low gear to fine tune or improve the short times. In the remaining gears, use as little timing as possible and rely on additional boost to make the mph.
I have seldom seen more than 18 degs of timing in third gear make the car go any faster, but, I have seen cars slow down on more timing because they could not make the boost.
Coincidentally, the larger the turbo, the less timing one can usually run. And also, the more alky one sprays, the faster the car will go assuming one does not put the fire out in low gear with too much.
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Trying to make a car run it's best time in 85* weather is bound to frustrate anyone.
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LOL...and I would think what a nice day :rock:
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On Earl's link they were talking 50C. approx 130F. Where is ambient that high?
Seems to me the new Dodges have some good working systems and the aftermarket have improved on those.
85 in Texas IS a nice day but when you live in the great lakes area not so much LOL.
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I think he was using 50 as the ambient temp of the IC under the hood rather than air temp as most of us would think. I don't think 130 is too far off from what I see around here in the warmer months. Air temperature right off the pavement is a killer
It's been unusually cool around here so far, but, forecast is for more than 100 today and it is still humid so the heat index is about ten degrees higher.
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On first pass intake air temperature was 101 at time I let the brake go.
Last pass it was 127.
I’m happy with 11.5 pass that was my goal. You look at the times slip and say ok just a little more and high 10. Couple years back I the tech guy made mention when I was running consent 11.80sto watch it.
Maybe it’s time to focus on my reaction times.
I think it’s time to give Lonnie at Extreme automatic two thumbs up on trans and converter. He did it with a Sprag so I can drive it anywhere any time without haven a heating problem.
Thanks everyone I’ll keep adding low gear timing tell I get a little Kr and back off a few numbers
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just a little more and high 10.
In a perfect world, about 70 hp to go 11.0.
http://www.wallaceracing.com/et-hp-mph.php (http://www.wallaceracing.com/et-hp-mph.php)
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Those FB threads ,Rob Ortosky, Ken White and others - some good stuff in there. Wish my retention was still up to snuff.
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Particularly when spraying alky, I notice that some of the guys that actually measure temps and such stuff are beginning to go back to stock location intercoolers and are still knocking on the door to the 8's.
I was a firm believer on stock location intercoolers. We went back to one in Melissa's. :rock: Down to 9.1s now.
Tim now it's time to work on the suspension. ummmm.. Are you goin to just keep it at mid 11s ?
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Earl, I don't think I have seen that particular article before. It sums it up nicely altho' I am sure that 90% will want to argue about what color to paint the intercooler to make it cool better.
I think I will save the candles after my next seance. :tongue
Phase change is neat shit when it works in our favor. That's a LOT of energy that can harnessed for both good and evil.
A nice insulating paint layer to ''aid'' in radiation on the other hand....
(https://scontent-atl3-1.xx.fbcdn.net/v/t1.0-9/33227961_1308099799325474_7290661273623068672_n.jpg?_nc_cat=107&_nc_eui2=AeGoEcr-uRJL4QvpLwgCxoz_bT23geEMO-2lfemRK6lUBlKFXZlPS86Q8wHzoagGe0-2xrhsYn5WcJp-3ZGfx6FWih_idlReB8kmc4s5LSuRjA&_nc_oc=AQnAMutl50PHco2BTph24sAjBvgOaTyphRwdCCzG6bUgb6RrlImej1qJKQJhiYInSsw&_nc_ht=scontent-atl3-1.xx&oh=48557809abe713b25fef2c61e5f98020&oe=5DC2C1E3)
...and Ive found a good source for wax is nipples. :D
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I have a old 15 row Action SLIC not planing to replace it.
Good question about staying med 11s ,I have a nice 87 and installing a roll bar ,Could cost a arm and leg here and might not be that nice of a job.Not saying it couldn’t be done, just pessimistic.
At 1.687 60 no 10 potential yet, but my suspension modification so far it sticks the tires most the time.
Lonnie and Julio recommend loosing the converter, but it’s street manures are so good. They also said I need to keep working on the tune. Going back this weekend adding more timing in 1st and 2ed. Once I get my A/F with no KR in 1-2 I’ll start on high gear tune.
Baby steps I have a 2step but I’ve gotten this far without it.When I got it my 60 had no improvement with or without it ,just another dodad to confuse me ,but it’s rev-limiter as save me a time or too.
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I have come to the conclusion that tuning is really a lot more simple than we make it to be with today's modern chips. Gorilla tuning will get you 99% of what days and days of fine tuning will bring you :)
1) if you can leave at 10-12 psi of boost, or better, without undue spooling delay on the line, then your converter is close on stall. I suspect the rpm will flash well into the 3000's and probably closer to 4000. Upon launch, it should flash to about the same rpm as it drops back to on the shift to second and third. Modern converters seem to be able to do this and still feel responsive in normal daily driving. I hate that "give it some gas and wait for the car to start moving" feeling.
2)Don't try to run the max timing in low gear that you can get without KR. Run enough so that the car will spool easily. Eric's chips are often too rich on the default so pull as much as required to get the revs to come up easily along with the timing. You don't want to heat the chamber in first and second more than you need to in order to get the car to launch. Any more just increases the likelihood of KR in third gear where the increased load on the engine and high chamber temps don't go together.
3) Don't worry about third gear timing. 18 degs will probably work as well as anything.
4) Stay in the power-band of the engine. Don't try to push the upper rpm limit. It's a turbo car. Boost is king and anything else is a pawn. Yes, I know the difference between flow and boost but we are only working with one turbo and one engine combo at a time. Just try to stay within the efficiency window for your turbo. If you increase boost and the intake temps take a steep jump, go back down.
5) learn to drive the car that you have...find out what works with it, not some one elses in other words.
6) The more alky you spray, the harder it is to optimize the launch, but, the safer the engine is on top end. Also, the more alky you spray, the less sensitive the tuning will become for A/F ratio.
Speaking of A/F's, I suspect that low gear should be around 11-1 and third gear should be around 10.8-1. Getting too rich will kill acceleration, getting too lean can cause strange noises. I suspect the fast alky cars are running egts around 1650 at the big end.
Your slic is fine. Watch who is running what at the nationals this year in the alky class. Slic's are easier to tune and more responsive on the street.
Quick street cars are a helluva lot more fun than real race cars unless you are just an old fashioned masochist at heart.
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Earl Brown, Life would be so monotonous without people like you around!k Gonna wax up my nipples tonight and hit the bars! NOT
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You'll strain your neck less, if you harvest the wax from a nipple donor.
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I would like to say, "I hear that!" but I don't
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85*, haha, try triple digit temps . 85* is a holiday.
https://m.youtube.com/watch?v=5ZftFnLMnwc (https://m.youtube.com/watch?v=5ZftFnLMnwc)
I listened to a podcast just this am about intercoolers and such. They had some opinions on em and intake temps with different fuels
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https://youtu.be/sMt6DbB4PdI (https://youtu.be/sMt6DbB4PdI)
My 85 degree day
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looks like a nice day for a strip cruise
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I liked the video. It runs good. Got air bags in the rear?
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Nice run on the vid! Keep pecking away at the tune by trial and error is all you can really do.
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Thanks no bags
Hellwig bar
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Have some one stand behind the car when you are spooling the turbo to check if the rear bumper is staying parallel to the ground. If not, an air bag or a stiffer roll bar may be helpful.
Watch it on an actual launch as well at the strip
Kevin Slaby's rear upper control arms relocation kit is also a good idea given the poor geometry on a GBody as well
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I didn't see any real issues, at this level. That is why I guessed air bags. Typically, a G-body is beginning to show symptoms @ 1.6 short.
I would not worry about it until it breaks loose as the rear unloads. They typically squat on the hit and unload in about 10-25 ft. This car apparently has good rear shocks and a smoooothe power delivery.
Anyway, you can video the launch and slow it down to find out. You probably won't feel it.
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Three weeks ago. I added air fixed the tire spinning
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what boost are you leaving at?
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15 to 20 at 3100 to 3600 at that you think it would be wheels up
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117mph is solid horse power. Hooks well. Or seems to. Short time? What about the other splits? What kind of mph is it picking up In the second half?
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I agree. Something is not right at that point. It should be wheels up or blowing the tires away. I would expect a 1.5 short time
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It acts like it hits full boost after rolling out for a bit. Is it spraying alky while your spooling?
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or, the converter is not doing its job and is absorbing the "Leave" instead of handing it to the rear tires?
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I would listen to Lonnie and Julio at this point. [converter]
With a 3500 n/l I didn't even notice it was there until I got in a stocker. I certainly never got the, wait for it to hit, people talk about.
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I’ll post time slips tonight on the split
Turned Alky of for a short 60 foot left leaned out to 12.2 no improvement in 60 ft time
Tried the 2 step at 3600 worst 60
Got enough data and time slips for Lonnie to restall the converter to best Mach my combo.
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I’ll post time slips tonight on the split
I would like to see the reaction times as you were staged somewhat shallow in the video.
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I didn’t care about reaction time just trying to figure out the lousy 60
Best 60 second best ET worst mph
1.687
4.749
7.361
93.04
9.630
11.556
117.13
At 3100 rpm 15 lb
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Making good power on the back half [over 24 mph] but not putting it down in the front half. you are down approx 7 mph in the 8th. Comes back to the converter.IMO. What does it stall at 0 boost.
What exhaust housing on the car?
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The numbers look good to me. The 60' is about .9 sec slow from perfectly fine. I do not trust 60' numbers until I see a 0.0x RT after a very shallow stage.
The car runs 'clean'. No antics, no apparent counter steer, pulls from start to the stripe. For a heavyweight street/strip G-body, I like it.
JMO.
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Tim,
I have found that unless I get the boost in the upper teens low 20’s, I don’t see anything less than a 1.6 short time. I have a stock stroke .030 over 109. I stage at 35-3600 with the flash up to 4200. Full boost usually comes in within .4 to .6 after the launch. The 1-2 gears can usually get away with a bit more timing and a leaner AFR. If you can get a log that would help folks make suggestions. Good luck and stay safe
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I’ll try again to post the log I’m not the sharpest knife. 35 to 36 not happening after adding timing I could before adding timing.
Think I flash at 4500? That’s were it falls to after every shift. Is that flash?
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No, flash is the rpm that you hit as soon as you take your foot off the brake and the car moves about a foot or two.
If you can post a long, we will tell you
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hope this worked
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this is the right one
the first was no alky.I made a big booboo testing the Alky pump first thing and forgot to plug in the map.
it did answer a question I had about being so rich just before letting off the brake,it was nice and lean and same 60 foot time.and did not respond any different before KR