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My son's car, 4.8, sloppy cam, truck intake, home-made turbo piping, Terminator X, VSR Gen 2.5 billet 78/75 w/1.25 a/r, 4" fender exit, E-85, etc., etc.,
Father & Son Project that's finally "almost" ready to race, lol.
The "almost" part:
He has had absolutely no luck controlling boost, using the "Sloppy" MAP sensor method, open or closed loop.
He's tried 3 and 4 port MAC valve. I believe he has even tried using PWM.
I'm familiar with my HPTuners, and use a $275 Turbosmart Boost Controller, (which right NOW, works 100X better than his setup, with the Holley), so I haven't been any help, to be honest.
Honestly, I am puzzled why my low dollar boost controller, literally only needs a boost source (hose), to fully control boost ramp, scramble, overboost shutdown, and anything I've ever needed with my simple combo? But Holley needs extra dome sensors, and/or wire splices, Co2, or some other trickery to make theirs work? I can make 4#, or I can make 22+ with a turn of the ****. Weird..
anyway...
First day to track, car won't make over 3-ish# on transbrake, yet even set at what he thinks is (or should be) 10# of TOTAL boost, ramps right up and well past that point, actually hitting boost cut, which pretty much shuts the car down, at 1000' or less...sometimes MUCH less, like at the 1/8th....
Boost Cut is set at 24psi...on his GoPro's you can hear the boost steadily rising as he goes down track...
He has one, maybe two more track days, so I suggested rather than continuing to dick around with this Holley Boost Logic, to simply swap in 16# worth of wastegate springs, and run the car, "on wastegate"...eliminating the Holley from most of it's boost control. That will also determine if the wastegate is, or is not, prioritized in the exhaust flow, like mine is. Obviously, if it still overboosts, then we're done for this year, and need to do some wastegate moving, like I did on my car.
He said if he turns the MAC valve OFF, it makes, and stays steady at 4-5# (w/4# spring)
Then he also has all winter to figure it (Holley Logic) out...although he said Motion has almost the entire Co2 setup on Black Friday special, for about $300, so I believe that's his end game...It's not worth any more trial & error aggravation with Holley's Boost Control, in these next 2 weeks.
Anyway, with no MAC valve in the mix, I am wondering if the Holley can/will still control the rest of the boost related "tuning", as in Overboost (boost cut), Timing, and the like? I believe that it will, since it will still get info from the MAP sensor, but wanted to check and confirm with those smarter than I...
On the brightside...
in a car that's been sitting for 4 of the last 5 years, he got 5 passes in, no smoke, no leaks, it drove straight as an arrow, hooks like it should, got a small "wheelie" pic, and ran a 10.88@121 with car faceplanting itself, and shutting down at 1000 feet...lol. His previous fastest pass (old car) was a 13.20@103, so this one is quite a bit different, lol.
I dont have a transbrake, but have been able to use the sloppy setup to control the boost pretty good. A dome sensor is prob a better way. I dont think the map sensor cares how you control boost, I ran a man. controller most of the time. Were you at Cecil, was going to go, I think this Sat is some makeup race besides
T & T, dont know how that will be. Capitol is closer, they have a couple T & T's left.
First of all a running car and making first passes is always fun, congrats! Everyone finds things they need to fix.
If it stays at 4-5PSI with the solenoid off, that seems to show your wastegate is doing its job and has decent enough priority, lower boost is harder to maintain than higher boost. How is the wastegate line plumbed to and from solenoid? Won't hurt to check the solenoid, but it seems like its working if you get boost to rise from the base 4-5PSI to 24PSI.
For the PWM method did you set an output to solenoid P- with frequency 30% and do an RPM vs MAP table? You can throw in 50% in whole table and hear it cycle without engine running. From there I set say 90-100% from 0PSI up to right before target boost, helps get turbo jamming, then drop the duty cycle down to 50-60 or whatver % you want to get your desired boost.
As far as running on a higher gate spring without any holley input yes you can still cut timing like normal. You just don't have the "revert to gate" option without the solenoid in the loop.
I dont have a transbrake, but have been able to use the sloppy setup to control the boost pretty good. A dome sensor is prob a better way. I dont think the map sensor cares how you control boost, I ran a man. controller most of the time. Were you at Cecil, was going to go, I think this Sat is some makeup race besides
T & T, dont know how that will be. Capitol is closer, they have a couple T & T's left.
PM sent back.
Yes, we went Sunday. It was a fully prepped $150/car private rental, which I would have LOVED to race my car at, lol. Everyone either wheelies or broke a u joint, driveshaft, or rear, lol.
This Saturday is a makeup race, which will be packed. There's 8 classes and a test & Tune, which means lots of waiting and maybe 2 runs, IMO.
Capitol has some Capital Car Club race day,, which looks like Lambos, Beemer, etc., which means 99% of them will have no clue WTF they are doing, ie; another long day of waiting. Not sure which one he wants to go to.
First of all a running car and making first passes is always fun, congrats! Everyone finds things they need to fix.
If it stays at 4-5PSI with the solenoid off, that seems to show your wastegate is doing its job and has decent enough priority, lower boost is harder to maintain than higher boost. How is the wastegate line plumbed to and from solenoid? Won't hurt to check the solenoid, but it seems like its working if you get boost to rise from the base 4-5PSI to 24PSI.
For the PWM method did you set an output to solenoid P- with frequency 30% and do an RPM vs MAP table? You can throw in 50% in whole table and hear it cycle without engine running. From there I set say 90-100% from 0PSI up to right before target boost, helps get turbo jamming, then drop the duty cycle down to 50-60 or whatver % you want to get your desired boost.
As far as running on a higher gate spring without any holley input yes you can still cut timing like normal. You just don't have the "revert to gate" option without the solenoid in the loop.
.
I agree if it's steady boost with Mac valve OFF, it has to be an OK location for gate, BUT...he may not have given it time to creep either. He is a very green, newbie with a car that can make some actual power. I'm trying to let him figure stuff out himself, for the most part, but see he's getting a little flustered right now.
I'd have to ask him when he stops by later, about how he had what set and how.
As long as it will not harm anything NOT using boost control as most can and do, that's what I needed to know.
take some data logs with the stupid little screen if you dont have a prodash. thats where all the real magic is in all this efi crap.
I know he logged every pass, and had his laptop on board, logging with it . I also recall the MAC valve reading was negative. I assume because it was trying to lower boost.
I only have a phone for internet until tomorrow morning. I believe I can attach a log or logs tomorrow on here, using my laptop?
My neighbor went Sunday to that rental, he has a 2018-2019 LT1 Camaro, lot of work.
He went like a 9.65 he said.
There was a lot of nice cars (& trucks) there Sunday. Prep was great and they stayed after it all day.
Difference between a $150 rental and a Friday Kid's Night Test & Tune 😉
FWIW, forcd ind uses the MAP for reference and has no issues running boost control, and he was kind enough to send me a copy of his "Sloppy MAP Boost Control" tune, which I forwarded to my son, to compare.
They're identical, aside from max boost numbers, so we're going to first take the Holley 100% OUT of the boost control mix.
Then, re-route boost reference directly to bottom port of wastegate, since it only has a 4# spring in it.
If the 4 to 24# "rapid creep" is gone, we'll know the gate position isn't the problem.
Then, we'll put the 16# springs in for Saturday Test & Tune.
But...If it still seriously overboosts, with the 4" spring and reference line direct from turbo to lower gate port, then I am going to veto taking it back to the track, until we can "priority plumb" dual gates just like my car has. He already has 2 new 44mm gates, same as I have, and I already know if plumbed correctly, they work great.
FWIW, forcd ind uses the MAP for reference and has no issues running boost control, and he was kind enough to send me a copy of his "Sloppy MAP Boost Control" tune, which I forwarded to my son, to compare.
They're identical, aside from max boost numbers, so we're going to first take the Holley 100% OUT of the boost control mix.
Then, re-route boost reference directly to bottom port of wastegate, since it only has a 4# spring in it.
If the 4 to 24# "rapid creep" is gone, we'll know the gate position isn't the problem.
Then, we'll put the 16# springs in for Saturday Test & Tune.
But...If it still seriously overboosts, with the 4" spring and reference line direct from turbo to lower gate port, then I am going to veto taking it back to the track, until we can "priority plumb" dual gates just like my car has. He already has 2 new 44mm gates, same as I have, and I already know if plumbed correctly, they work great.
Stay Tuned...
Sounds like a plan.
Just FYI - With the PWM method and line from solenoid only to bottom port of gate I've been able to get as low as 2 PSI commanded on launch and 30+ PSI down track. I don't know why so many people over complicate boost control.
While I don’t have any input on your problem, I do appreciate your nice *** ride
Thanks a bunch. I appreciate that.
Originally Posted by SLOW SEDAN
Sounds like a plan.
Just FYI - With the PWM method and line from solenoid only to bottom port of gate I've been able to get as low as 2 PSI commanded on launch and 30+ PSI down track. I don't know why so many people over complicate boost control.
Appreciate your feedback, as always...and thanks for the bolded sentence. I feel exactly the same way.
No idea why we'd have to use dual MAC's, CO2, compressed air, dome sensors, 1/2 dozen different boost hoses, 3 pages of boost logic, and 35 YouTube videos on it, lol...
I MUCH, MUCH prefer simplicity that works...
p.s. He isn't too enthused about my possible veto, lol.
Appreciate your feedback, as always...and thanks for the bolded sentence. I feel exactly the same way.
No idea why we'd have to use dual MAC's, CO2, compressed air, dome sensors, 1/2 dozen different boost hoses, 3 pages of boost logic, and 35 YouTube videos on it, lol...
I MUCH, MUCH prefer simplicity that works...
p.s. He isn't too enthused about my possible veto, lol.
No problem! I say keep things caveman simple on race cars, makes it easy to troubleshoot and easy to fix! Hopefully a simple mod makes it work better.
Concerning the Veto, if all else fails and boost still creeps, perhaps raise boost cut a bit and see where it creeps to? Its a 78mm on a 4.8L, letting it ride out the back on whatever boost it wants to make isn't the worst thing especially if you keep timing low in that upper MAP area and the fuel system can support it. If it took to 1000' to get to 24PSI that's a pretty slow ramp, it may only go up a little further.
No problem! I say keep things caveman simple on race cars, makes it easy to troubleshoot and easy to fix! Hopefully a simple mod makes it work better.
Concerning the Veto, if all else fails and boost still creeps, perhaps raise boost cut a bit and see where it creeps to? Its a 78mm on a 4.8L, letting it ride out the back on whatever boost it wants to make isn't the worst thing especially if you keep timing low in that upper MAP area and the fuel system can support it. If it took to 1000' to get to 24PSI that's a pretty slow ramp, it may only go up a little further.
He just texted me.
He said on his 10.88 pass, he had boost cut turned OFF, and boost set at what he said should be 12#.
Launched at 2.7# @ 2900
5.9# top of 1st gear,
midway through 2nd gear, went from 8-22# "fast", in his words, lol.
3rd gear was 22-24#, and when he saw it was that high, he let off (approx. 1000 feet)
He has a toggle switch that he can turn ON, for Holley/MAC boost control, or OFF, for wastegate spring boost.
He said he has already tested the current wastegate/4# spring by turning MAC off, and making a 2nd/3rd gear pull on the highway.
With MAC off, it stays at 3.4 - 3.6#
He had an issue with the original wastegate, bought used (and ended up having a blown diaphragm...
Running closed loop, with old 3 port mac, it overboosted, as expected, with bad gate.
He said when he put the new wastegate on, he also (for whatever reason) swapped to a (used) 4 port mac, which evidently is faulty, and was running open loop boost control...he said on the logs, you can see the mac valve voltage trying to make it work, but zero change to boost, as if it's stuck or something...lol.
TODAY, after work, he wants to (leave 4# spring in, and) try a brand new genuine 3 port mac valve, running open loop PWM, with boost reference just to lower wastegate port, as you described above. If that doesn't work...although it should...he's swapping on the gate (brand new) that I put the 16# springs in
TODAY, after work, he wants to (leave 4# spring in, and) try a brand new genuine 3 port mac valve, running open loop PWM, with boost reference just to lower wastegate port, as you described above. If that doesn't work...although it should...he's swapping on the gate (brand new) that I put the 16# springs in
First off, thank you guys for offering suggestions, tips, and advice. It is always appreciated!
I thought I had updated this post...obviously, I did not.
On the limited areas near our house to make a "test hit", the boost seemed to be controlled.
At the track this past Saturday, it was no different.
Launch on 4psi, and with 4# spring, midway through 2nd gear, made 22#
The track we went to, Capitol Raceway, appeared to be (unbeknownst to us) totally unprepped and I literally never saw one car actually hook. Was a wasted day, although got to spend some quality time with my son...
As for the track surface...Even my old buddy's all wheel drive Tesla Plaid was losing traction at various spots downtrack...
We'll be yanking off the hotside, and converting it to dual 44mm wastegates, just like my car has. I know it's overkill, but I also know that will cure the boost control issues.
Bottom line is, my son got to make 8 passes or so in the last 2 weekends, on a car he loves and has put a lot of time and money into. He had zero issues, aside from the overboosting, which is a very "fixable" issue.
He got a 10.88@121 with car shutting off at 1000', on 2nd or 3rd ever pass
I'm confident it'll be an easy 9 second car once the boost controlling is right, & tune and suspension are dialed in.
The Sloppy map input boost control method seems to be hit or miss. I tried it on the Volvo and a 370 fox body I tune and couldn't get it to work. Uncontrollable overshoot and oscillation that does not responsd well to PID or target rate limiter settings. I converted the Volvo to open-loop & 4-port with a Target Boost vs RPM PWM table and have the DC% dialed in nicely up to 10psi and that's as much as I'll do on the street. The Mustang is more racecar, so we put it to closed-loop with on-board air and dual 3-ports. Today, I went to dial in the PIDs with the t-brake release/strip chart method and was surpised how well it worked. Set up a funky Boost vs Time table that started at 7psi, ramped to 30psi in .8 secs with 2 sharp dips to 10psi and the dome pressure tracked that erratic table perfectly. We'll see how well it works Sunday at the track.
If you connected the compressor to the bottom and went from 4 to 22, then something is preventing the diaphragm from moving up to compress the spring to open the valve. Was the dome port vented? Possible ripped diaphragm or not properly seated between the 2 halves? Sticking or bent valve preventing full travel? Seen this issue with the last 2 possibilities.
Thanks for the compliment. He's got the Fox body hatch stuck in his memory. I had about 20 of them back when they still had Ford engines,, lol.. His is very similar (except color) to one of my best looking ones, attached below.
He originally thought the wastegate was the problem, and he bought a brand new one, a VSR 44mm, which is what I also have. Everything works as it should OFF the car, using compressed air,, so we're going to run dual gates, just like I do, to eliminate the problem once and for all.
Here's one of my better Fox bodies,, which I think is what he remembers most.. The zoomed in shot from the rear is him,, when he was 7 years old,, riding with me down the Boardwalk in Ocean City Maryland cruise week parade. Car went 10.22@133 twenty years ago, with a handheld tuner called PMS, acronym for Programmable Management System, which was pretty damn fancy for the times...lol
11-16-2021, 12:31 PM
Terminator X Boost Control question 
