patsmx5

iTrader: (16)

Also spoolup is better and faster, 3.55's don't pull nearly as hard at 4.10's, I probably added 40-50lbs with the new drivetrain so again, it's tough but the extra weight isn't helping, and we had a headwind all night. But it was like 50*F so that helped on the power at least. I'll keep an eye out on youtube to see if any vids pop up that show my car, but I didn't get any so not likely to get any.

Oh yeah, new best 60' time of 1.66!

nitrodann

This is awesome.

Youre a clever and driven guy pat.

Well done

sonofthehill

iTrader: (1)

^^^^
This, congrats on the 60'. Hopefully you can get the spool valve working right.

oreo

^^^ very nice, congrats!

What parameters are you using to control when the spool valve opens?

patsmx5

iTrader: (16)

Thank you for the kind words. Glad you like it! I try not to give up, and just keep going until I make things work.

Thanks! I will get it working soon.

Thank you! To answer your question, I have both the rear wastegate, and rear spool valve, both plumbed to the same hoses. Bottom port goes to boost, top port goes to a boost controller. Ideally the valve would open right before the wastegate, so I put a stiffer spring in the wastegate than the quick spool valve in hopes that the spool valve would open first. But it seems that's not working right. Again it's a guess but I suspect it's either not opening at all, or if it is opening, only a little so functionally it's not opening much and still choking flow.

Plan is to setup a small microcontroller to PWM the valve so I can switch which port is getting boost. That way during spoolup pressure goes to top port and pins it shut, then when it gets close to wastegate setting, it will PWM over to only pushing on the bottom port so that it pins the gate completely open for max flow to the second scroll of the turbine. I was hoping to avoid needing this system, but datalog and time slips are suggesting it will be required.

oreo

This is an interesting control problem. If you suddenly opened the spool valve, I think you need to close the wastegate to maintain boost.

Would the uP monitor the wastegate duty cycle, and keep opening the spool valve, if the wastegate was being cracked open? (so, basically PID the spool valve, based on wastegate duty?)

oh-oh, my heads hurting now.

patsmx5

iTrader: (16)

To keep it simple, I'm going to PWM the spool valve over a fairly wide range, say 3-4 PSI, and do that before the wastegate ever starts to open so that those two systems don't interfere with each other. Keeping the range from open to closed a few PSI apart will make tuning it managable as my primary fueling is done via MAP, and it shouldn't oscillate too much I hope. The uP would only monitor boost pressure and adjust duty cycle from 0 to 100% when it's in the range to do so, then stay 100% once it goes over that. A few PSI later, the wastegate will crack open and maintain the desired boost level.

oreo

^^^ Ah yes, "keep it simple". That seems to be your motto.

Sounds like you have a good strategy.

ryansmoneypit

iTrader: (6)

I need to learn to have patients like Pat. This is pretty damn cool man, great job! I cant wait for when its actually race ready.

sixshooter

iTrader: (12)

Dr. Pat?

sonofthehill

iTrader: (1)

PhD
The difference between doctors, PhD's have no patience.

patsmx5

iTrader: (16)

Thanks! Glad you like it! I too am looking forward to getting some good passes in the car. I've been super busy, and haven't had any time to wrench on it since I raced last week. I gotta work through this weekend, but hope to get a few things done next week on the car in the evening time and get back to the track next week. I do love racing and driving the car, but I also enjoy the fabrication/design aspect as well. That helps me keep going when there's lots of work and building, and not much driving. But I'm hopeful most of the drivetrain wrenching is done for a while!
Ha! Sounds cool though.

LOL.

patsmx5

iTrader: (16)

Update!

So, I haven't had much time to do anything to the car lately, but I wanted to race it tonight. So around 3:30 PM I pulled the spool valve, tested it to see when it cracks open vs when it's fully open, and found that about 6 PSI is enough to completely open the valve. That's great news, that means just disconnecting the top port, and running boost to the bottom port, will result in it being fully open by 5-6 PSI. Which for now is what I want, just to get the power back till I can make a controller to PWM the valve or something. So did that, test drove, rolling burnout on drag radials on concrete, yeap, valve fixed power. Then I gave the boost controller a twist, made another pull, damn it was moving! Well over 400whp that pull, 32PSI boost, 77% duty cycle on ID 1300s @ 60 PSI base pressure with 1:1 reference. Ran great. So I fueled up and headed to the track. But I noticed it wasn't spooling right for some reason. Weird, like it's really heatsoaked or something. And when I accelerated, I could smell something too. So I pulled over expecting to see a boost leak or something. Front turbo is puking oil everywhere. Engine is a quart low on oil. Nursed it home, no track time today.

Soon as I got home I put a huge fan blowing on the hotside parts to cool it all down, and about 30 min later I had the turbo off and then tore it down. Thrust bearing showed a tiny amount of wear. Rear bearing was ok, front bearing is shot and compressor wheel hit the housing, and front seal was puking oil everywhere.

Sad because this turbo had no shaft play at all 400 miles ago. It seems that one pull into the low 30s in boost killed it. Lame.

Mocking up the EFR 7670, seeing if there's any way to put this thing one and not have to cut the hood skin. I don't want to get my hopes up, but it's looking like it might be doable.

If I can get it to fit, EFR goodness here I come!

I gotta pull the intercooler and clean it as I'm sure it's full of oil. I have a bigger intercooler, gonna see how much work it would be to install while the bumper is off.

FWIW, I think the ebay turbo failed due to a crappy balance. Can't say for certain, but that's my guess.

nitrodann

You are a machine Pat. An animal mate,

Are the bearings stuffed because the turbo internals are embedded in them?

Dann

18psi

iTrader: (76)

bummer on the troubles, but I'm really excited about the bolded part. we already know chinabay turbos don't last long on high boost, and that the EFR will be glorious

sonofthehill

iTrader: (1)

Sorry to hear that Pat, at least it was a cheapie. I have also been thinking about EFR, built in recirculation valve would solve my woes. Not to mention all the other EFR goodness. Good luck with the fit.

patsmx5

iTrader: (16)

The bearing is worn, the shaft looks fine to the eye. I highly suspect the compressor wheel was out of balance and is what caused the failed bearing. It could be rebuilt with new bearings and a rebalance, but I probably won't do anything with it, or at least I don't foresee doing anything with it right now.

4 years after buying this turbo, it's finally going back on the car!

Thanks.

So didn't make a whole lot of progress today, but I did get a little bit done. Good news is, after much clocking, and cutting of the hood structure, the EFR has about 1/8" to 1/4" clearance to the hood skin with the hood shut! So it will probably hit when the motor torques over but screw it, EFR boost here I come! Gotta mod the downpipe, boost pipe, water pipes, oil line, oil drain, etc. But I didn't have to modify the manifold so EFR is happening.

Also pulled the old intercooler, as expected it was full of oil. I cleaned it, tried to dry it and more oil came out so gonna clean it again dry it again. I have another cheap intercooler that's bigger than this one, but it's tube/fin and crappy design. I tried building a simple leaf blower/fan/thermocouple thing to see which one rejects heat better, but my test apparatus was too cobbled together to get a clear idea of which was better. Tomorrow I'm going to improve the test setup and repeat the testing to see which dumps heat better, and whichever is better is going on the car.

Either way, I'm relocating the intercooler. It was previously flipped upside down to make charge pipe routing short/easy. It was also fairly high up in the stack, and that gave excellent air to the radiator, but not so much to the intercooler. And at high boost AITs were a lot higher than I wanted. So it's going to be flipped so the inlet/outlet are on the bottom where all the airflow is, and moved down a lot into the air stream for better AITs. Hopefully I'll have better AITs with whatever the new setup ends up being. Will have to redo all my intercooler pipes which suck, but oh well.

portabull

i can send you a tool that will easily put a little bubble in your hood over the turbo. i used it to get clearance for the lfx in mine. it could be pretty subtle, kind of like a smaller version of the bubble in a triumph tr4a.

patsmx5

iTrader: (16)

If the turbo hits, I may take you up on that! Thank you for the offer!

Ok, small update. I redid my intercooler testing today. This time I used a leaf blower blowing air through the intercooler. It heated the air about 10* relative to ambient just from the fan. Then I used a 1500W heat gun blowing air into the inlet of the leaf blower. That got the exit temp out of the blower to 39*F above ambient. Then I used a squirel cage blower to blow air across the core to simulate a bit of airflow. I took temp measurements at 1min, 5 min, 10 min. Used a thermocouple to take temp readings.

The old intercooler is a bar/plate, 20x12x3 core, with meh fin density on the inside, but about right on the outside.

The new intercooler is tube/fin, 24x12x3.5 core, with aweful inside fins, basically just a big tube with a few dividers in it, total joke. When I bough it the pics looked great, but what arrived was not what was shown. But outside fins looked good.

Tested both, and the bar/plate won handily. If the tube/fin had the same internal tubulators that the bar/plate had, I think it would have won as it was bigger and had other advantages, but it's poor fin design internally hammered it's effectiveness.

So got the bar/plate into position and started moking up intercooler pipes. It's now in the direct path of airflow so AITs should be better at the track. The new pipes, my goal is to make them with large radius, use none or as few silicone bends and straight sections as possible, and add support at the connections so the silicone isn't taking the force of the pipes trying to blow off. At 40 PSI boost, a 2.5" pipe has 196 lbs of force trying to pull the pipe from the coupler.

The pipes for the engine bay area are made, now I gotta do the ones that go under the car next. Passenger side is being a pain, but I should get those done tomorrow I hope.

I also cut my pretty downpipe since it has to be modified for the new turbo. I think I'm gonna need a new V-band to make it work, we'll see.

I sent full-race an email asking how much boost this EFR will run reliably, waiting on a response. I don't want to break another turbo! From searching it seems most don't push these past 26-28 PSI.

Mobius

iTrader: (2)

#ALLOFIT!