Intro and Update: Slugmobile and Mean Mini! (long read, but worth it)

[acannell]

I wonder though if it could be opened up enough. I think the fact that this is a ball bearing turbo, it really requires a larger wastegate, since it takes less to spin it up to pressure.

I pumped the actuator up to 25-30 psi, so it was open as far as the srm would travel i imagine. But, i could disconnect it. It is a bit of a tight squeeze with this .63 turbine housing and the 2pc lower manifold. That is why i opted to pump the actuator. I could try again though, it would be less work than removing turbo.

Assuming your turbo/WG setup is like mine, and you want to disconnect the arm, first you got to get a little screwdriver in there and pop the E-clip off without dropping it.

Then you have to pop the arm off, which should have some preload, so it will fight you a little bit but not too much. Or you can pump it out to take away the preload. Then I'd remove the actuator entirely to make sure the rod laying there doesn't interfere with the flappers ability to flap open.

Once you want to put it back on though, you are going to need to pump it out a bit to create that preload again. Then get the e-clip on there hopefully with just finger pressure because getting pliers in there is tricky and/or more likely to send the E-clip flying.

The ball bearings should have a negligible effect on steady-state efficiency. The bigger impact will be how efficient your turbo (turbine + compressor wheels/housings) and engine are overall, as far as how much less exhaust gas flow you need to reach your operating point.

I think it might be possible to measure if the WG puck is being forced open, by connecting the actuator to a vacuum gauge and seeing if the needle moves and how much. Could test that on the bench. The actuator itself has no bleed holes right? So pulling on the rod should generate a vacuum in the diaphragm chamber.

[Vigo]

Well, if exhaust pressure is forcing the wastegate puck open it would make your boost lower, and this is the opposite problem. I really doubt that will be a problem with this setup, though.

[acannell]

Well, if exhaust pressure is forcing the wastegate puck open it would make your boost lower, and this is the opposite problem. I really doubt that will be a problem with this setup, though.

I think the key difference would be, that in lesser engines, the puck gets forced open and the WG dumps flow to where the boost setpoint cant be reached because so much pressure has already been dropped across the exhaust/ports/swingvalve, etc..inefficiencies. But wheming comes along with mega-van engine and it cares not at all that the puck has been forced open and it just adds the flow through the WG hole to its bill and plops down Amex black... in other words it can afford the losses and still keep boost rising. Or is that not anywhere near realistic?

I dont really think thats happening here either actually. Not sure why I started talking about puck-forcing (sounds dirty)

[Aries_Turbo]

if it does force the puck open, its ok. just add an external spring alongside the wastegate can. take wastegate can off. drill small hole in the flat end where the flapper arm peg goes through. hook one end of the spring there. bolt a piece of metal to where the wastegate can bracket bolts to and attach the other end of the spring there. add threaded tension adjuster so you have just the right amount of tension to keep it closed enough so it doesnt spike. done.

Brian

[wheming]

Asa, we are discussing two issues, the immediate issue before us is not having enough wastegate to control boost to a set level. The wastgate port is not large enough to bypass enough exhaust energy around the turbine to control boost to a set level. That is the main issue. This therefore creates problems in trying to tune, since i can not at all control my boost pressure under continued WOT. It just keeps rising.
We are theorizing whether the port can even be opened up enough to bypass enough energy given that this turbo is very efficient (and has been modified for increased efficiency ) and thst the DBB design requires less energy input to spool. The same size port on a journal bearing turbo might not yield the same result.

I was postulating whether the port would be large enough that when trying to maintain ssy 25psi (or some elevated boost pressure) if the puck would begin to be pushed open. The fact of the puck could be pushed open is only an issue when trying to maintain a higher boost pressure. Then that scenario might require additional spring tension (and would thereby increase my minimum boost setting).

So you can see it is a bit of a balancing act, and why folks don't normslly just hog out the wastegate port to the maximum size the puck will allow without first knowing a starting point.

I was looking for 1 and done, and i just missed the mark a bit.

It is a challenge now to tune properly, but i think i may need to press forward like this if the puck flapping in the breeze yirlds the same result as actuator pumped up to 30psi.

On the street and driving normsl it has never been a problem. And the creep happens slowly. Like i said and you can see from the logs, the boost is about 22-23psi just before i shift to 3rd. I would just want it to be what i choose, until i choose it to be 23psi.
In tuning, i am learning. But i know the BEST way is to take it slow and add power a little at a time, and measure results and effects (knock).

[Force Fed Mopar]

I dunno if it's any help or not, but here's what my current PumpEff table looks like for my stock 2.5 w/ 2-piece, 52mm TB, ported exhaust mani, stock Garrett, AWIC and 3" exhaust. And this setting is a bit rich, 10.6 @ WOT and 15psi. Just something to compare with.

[Vigo]

in other words it can afford the losses and still keep boost rising. Or is that not anywhere near realistic?

Totally realistic, that's actually exactly what boost creep is!

I dont think worries about the puck being forced open are relevant in this situation. You can just fix that with spring tension. It doesn't necessarily raise your minimum boost, just get you back to the same place you started. The worst case scenario is that the wastegate flow after porting isn't enough and you go to the EWG setup you've already been contemplating. You're already mentally amortizing the cost of 'failure' if the wastegate passage porting doesn't work. You just wire/whatever the internal puck closed, and bolt on the EWG you already knew might be necessary.

So i dont think the question is whether the puck will ever be 'forced open', the question is just are you willing to take the chance that cheap/easier porting won't be enough vs the 'one and done' EWG install that costs more money and labor.

[Chris W]

Asa, we are discussing two issues, the immediate issue before us is not having enough wastegate to control boost to a set level. The wastgate port is not large enough to bypass enough exhaust energy around the turbine to control boost to a set level. That is the main issue. This therefore creates problems in trying to tune, since i can not at all control my boost pressure under continued WOT. It just keeps rising.
We are theorizing whether the port can even be opened up enough to bypass enough energy given that this turbo is very efficient (and has been modified for increased efficiency ) and thst the DBB design requires less energy input to spool. The same size port on a journal bearing turbo might not yield the same result.

I was postulating whether the port would be large enough that when trying to maintain ssy 25psi (or some elevated boost pressure) if the puck would begin to be pushed open. The fact of the puck could be pushed open is only an issue when trying to maintain a higher boost pressure. Then that scenario might require additional spring tension (and would thereby increase my minimum boost setting).

So you can see it is a bit of a balancing act, and why folks don't normslly just hog out the wastegate port to the maximum size the puck will allow without first knowing a starting point.

I was looking for 1 and done, and i just missed the mark a bit.

It is a challenge now to tune properly, but i think i may need to press forward like this if the puck flapping in the breeze yirlds the same result as actuator pumped up to 30psi.

On the street and driving normsl it has never been a problem. And the creep happens slowly. Like i said and you can see from the logs, the boost is about 22-23psi just before i shift to 3rd. I would just want it to be what i choose, until i choose it to be 23psi.
In tuning, i am learning. But i know the BEST way is to take it slow and add power a little at a time, and measure results and effects (knock).

Considering your boost creep comes on gradually I would estimate that WG hole porting would be minimal to control it. Keep in mind that the wastegate hole averages 22mm on Chrysler style turbine housings while our swingvalve pucks are 35mm. That's a 253% difference in area not considering overlap necessary to provide an adequate seal. Once again, we have 38mm pucks being made right now and if there is a need you could go larger but we don't feel that would be necessary.

Photo below shows 35mm puck shadow over 22mm wastegate hole.



Chris-TU

[wheming]

Thanks Chris, that's good to put things in perspective like that.

If the turbo comes off, i will enlarge it.
Do you have a reference for how the TU 35mm puck matches up with what is on the ATP swingvalve housing? Whose is bigger? ? ?

[Chris W]

Thanks Chris, that's good to put things in perspective like that.

If the turbo comes off, i will enlarge it.
Do you have a reference for how the TU 35mm puck matches up with what is on the ATP swingvalve housing? Whose is bigger? ? ?

One of the major advantages of the TU swingvalve is the larger puck size enabling you to port the WG hole and control boost creep. Factory swingvalve pucks are usually around 27mm and are not big enough for performance applications. Photo below is factory and TU puck comparison.

We are currently out of ATP swingvalves to measure and could not find specs on their site regarding the puck size. We will be placing our monthly order with them soon so will try to obtain the info when we contact them.

Chris-TU

[wheming]

Good info.
I can try to dig out the ATP ford swingvalve housing i have to measure. I would think it is the same. I never took a measurement on the one currently on MeanMini, or Slug.

[wheming]

They look the same size to me.

[wheming]

MeanMini update.
Got out racing again to Fayetteville Motorsports Park in NC on 8/21/2015.
(Some results and pics were already posted here: http://www.turbo-mopar.com/forums/sh...=1#post1089995 )

First pass set a new record for Mini. 13.0311 @ 101.60 mph (14.5 psi slicks, gvalve set for 14-15 psi boost)
That run was against a Mustang will have to look back and see about what year, mid 90's i think?
My wife Janet tried to get some video, and she was using my phone. Will have to look to see if they are worth posting.

Second run was against a newer 2014? Mustang GT 5.0
I hit rev limit in 1st and still had a crappy launch. Tried to bump up the boost a bit, but it didn't appear to be any different.
13.5660 @ 102.62 mph (tied my previous record mph though.)

And third run. Let car sit after second run to cool while I ate and made a few checks.
Tried to do a better burnout, so at this track the water box is concrete with a decent dip. I just quick spun in the water box, then pulled forward until the rears were in the box. I didn't use the e-brake because i didn't want to risk the cable not releasing all the way as it has in the past.
Then I did a staged lauch, spinning through first, shifted to second and it spun and hooked. that took me nearly to the staging lights but i was just a bit off to the right slightly. So I backed up a bit then pulled forward and staged. Shallow staged.
Launch felt much better! It was only a 1.8801, so there is still room to improve there.
Was racing an early 80's Chevy C10 P/U, and he really didn't know what he was in for...
12.5398 @ 109 mph (est. mph)

Here is the full .mpi file for the run, and the condensed .csv (includes the burnout through the traps):
As previously mentioned, 15psi in slicks, gvalve adjusted for about 18psi. (By the shift the boost is up to about 23psi.) Other details: 3/8 tank of fuel +1.5 gals of 112 VP Racing fuel (safety first), lightweight Bogarts on all 4's. Race weight estimate about the same 3120 lbs, maybe a bit less.

In the log i see I had a timing retard in 4th just after the shift to 3rd gear.
Also, the MPScan log does not appear to be giving me accurate RPM readings. My shift light recorded a max rpm of about 6300.
The last run i also made those small tweaks to the cal, changing the overboost setting to 29psi, and the rev limit to 6400. I set my shift light to 6150. (That is MeanMini_vBucar5a.bin)
Here is the link for the log files:
https://drive.google.com/folderview?...Ws&usp=sharing

[wheming]

Got a couple racing videos up on youtube. Wife took them and she is not a videographer. Can't see times and run 1 isn't even the entire run. But you can see the launch and early parts good.

Search youtube for "SlugmobileMeanMini" for the new videos.
Or here is my dragracing playlist:
MeanMini dragracing videos: http://www.youtube.com/playlist?list...URZLB1RxGYF6vw

[wheming]

And here's a pic before the first race of the night Friday.

[Reaper1]

SWEET! Congrats on the new record!!! Gus is smiling!

[wheming]

Thanks! Going back Friday 8/28 to try and get a better launch and back up that 12.5 run.
May also adjust my staging limiter up a tad.

[Ondonti]

How much boost is the setup happy for if you ran 100% race gas?

[wheming]

How much boost is the setup happy for if you ran 100% race gas?

I don't know.
So far she seems ok with the boost levels i see when creeped up to 23psi.
Most race fuel i've used so far was at SDAC when my brother Dan treated me to 2 gals of 112 to my 1/4 tank.
I put in 1.5 gals of 112 last friday to 3/8 tank and the logs looked pretty happy, but had a brief cyl 4 timing retard after shifting to 3rd.

Going to try to tweak my PumpEffTbl a bit for friday.
I know the timing is set pretty safe, and i do like a bit of extra fuel for safety.
I'll work things up slow, so i can inspect logs to try and catch warning signs early. I'm not out to be the fastest. I want to be safe and run Mini how Gus would be proud.

I relocated my air filter to test tomorrow too. Not getting air straight out of the radiator hopefully will help my charge temp.

[wheming]

So after Friday night dragracing on 8/28 i found my radiator was leaking at the lower tank crimp. The radiator in Mini was still a copper/brass 2 row core and i had a nice hayden 3710 fan.
Today i installed a new stock style aluminum replacement with a stock fan. I hope it will do ok. These aluminum ones are only 1 row core. There really was no provision i could see to mount the hayden fan. So i will try using the stock fan.
I also got my new sending unit installed for the trans temp gauge. The gauge i was using was just temporary. I'm in the process of trying to make a triple gauge mount.

I didn't start her due to letting the thread sealer dry on the trans temp sender. I'll have to start and burp the coolant still.

Also, i did receive my test fan for the intercooler. It is a small Spal fan 30103011. I'll need to order another now that i can see it should work. I'll just need some mounting kits.

With the air filter relocated, and with 2 aux fans on the intercooler, i'm hoping to be able to keep things a bit cooler.