Reality check on small 16g performance

[knochgoon24]

So I've been working on tuning my car. I'm getting an estimated airflow of 37lb/min at 20psi on a small16g with 6cm^2 hot side.

Here's the relevant setup:

• Small 16g
  
  -20psi
  -6cm^2 housing
  -light port job (focus on controlling boost creep)​
• Comp 101200 cams
  
  -Installed straight up​
• 3" downpipe and catback
  
  -3" cat and muffler​
• 2.5" tubular o2 housing
• Hard intake pipe w/ no MAF
• FMIC setup
  
  -2.5" piping​
• Stock 2g throttle body elbow, intake manifold, and exhaust manifold

Does 37lb/min even sound reasonable? If so, I'd be quite happy with that at only 20psi.

Bad news is that I might have also blown the headgasket tonight. No clue how. Just a white cloud of smoke on decel after a pull and haven't touched the car since getting it home. No knock, 11.4AFR, and conservative timing (5* peak load increasing to 10*).


EDIT:
So I think the estimate in EvoScan is a bit off in my situation. Max flow out of a small 16g is about 34lb/min. I don't think I'm maxing out the turbo just yet.

 

[MrBoxx]

Did you check for shaft play on the turbo? Smoke on decel after boosting could be indicative of a blown turbo seal. Does it smell like burning oil or coolant?

 

[JusMX141]

That's really good airflow for a Small 16G! Hopefully you didn't hurt your car or the turbo.

 

[knochgoon24]

The exhaust didn't have any oil or gas stink to it during idle.

The cloud of smoke it left out was impressive. It lasted the whole 10 seconds as I coasted after the pull.
I'll double check the shaft play tomorrow. It was fine a week ago. Then again, today was the first time in almost 6 months that I had the boost back up over 20psi.

Note on the original topic:
So after some quick math with logged IDC% and AFR, I'm over the 30lb/min point. I had about 28lb/min at 17psi. I didn't log the IDC% for the pulls after I upped it to 20psi so I don't have an exact number.

I'm not sure how EvoScan calculates its airflow value. It's a calculation that's done inside the Ecu with a formula programmed in buy one of those ECU guru's on EvoM.
EDIT: Found it's based on the airflow rate calculations based on OBD-II diagnostics. No surprise it's a bit off.

 

[snowborder714]

I'm seeing about 39-40 lb/min at 21-22 psi on my small 16g via link. I can post logs if you'd like so you can check out other values.

Stock 1g 7 bolt, stock o2 housing, 3" downpipe and 2.5"cat back, SD setup with 4" intake pipe, SSAC FMIC, 1g throttle body and intake manifold.

 

[toofast82]

I'm seeing about 39-40 lb/min at 21-22 psi on my small 16g via link. I can post logs if you'd like so you can check out other values.

Stock 1g 7 bolt, stock o2 housing, 3" downpipe and 2.5"cat back, SD setup with 4" intake pipe, SSAC FMIC, 1g throttle body and intake manifold.

Impressive
This is on pump gas and how much timing are you running?

 

[knochgoon24]

I couldn't wait until morning. I went and checked the shaft play. It has some wiggle to it. No in/out play though. I'm not sure how much is too much. I'd say about 3/64" up-down and left-right on it now. I can check it closer tomorrow.

 

[snowborder714]

Yep, on 93 pump.

I think it might be conservatively set at 16* at the top for right now.

 

[dsmdeliveryboy]

Wow, that is a lot of flow out of a small 16g.

 

[knochgoon24]

Yep, on 93 pump.

I think it might be conservatively set at 16* at the top for right now.

Then my timing is conservative for sure. I'm only at 10* up top.

 

[snowborder714]

Ya it is. I had it pushing 19-20* at the track a few years ago with 116 in it, but have pushed 17-18* on 93 pump.

 

[ziggo0]

Would a 7cm^2 exhaust housing help out s16g?

 

[knochgoon24]

So with 11.4AFR and conservative timing, there shouldn't be any reason so suspect it was the head gasket that let go. It has ARP head studs and a composite head gasket.

 

[snowborder714]

I personally wouldn't suspect it, but obviously would check it out.

 

[toofast82]

Yep, on 93 pump.

I think it might be conservatively set at 16* at the top for right now.

Wow, yeah that is conservative. Good numbers for sure on the 16g
I was running 19-20* on 23-24psi on 93,

 

[knochgoon24]

I'm really hoping I can still drive it out to the Sonic meet Sunday. I have people that are interested in buying both of my sets of rims that I have up for sale.

I guess that since I'm at school and don't have all the tools I usually do, I'll just check the turbo a little closer tomorrow then drive it and see if it happens again. I'll turn the boost back down to at least get me through the weekend. My compression tester, leakdown tester, and air compressor are all at home. I'll keep an eye on the coolant and oil.

 

[snowborder714]

I want to go, but I don't want to drive the car if it's supposed to rain all Sunday.

 

[knochgoon24]

I'm trying to figure out how I'm going to fit 8 wheels with tires mounted on them in my car. I think the passenger seat is going to have to come out.

 

[snowborder714]

I had a tough time trying to fit 4 18"!! You might need to remove all the seats and sit on 2 wheels.

From Eric (after a comment by me about using longer wheel studs): "Double dually."

 

[ZenkaiRacerDsM]

Smoke on decel can also be indicative of bad valve seals.

 

[knochgoon24]

Oh. It was the turbo.

YouTube - small16g shaft play

Another one bites the dust.

 

[JusMX141]

Holset time? I think I'm out of good Small 16G cores!

I'd be interested in seeing what went wrong if you're up for tearing this thing down. The head feed is normally the perfect amount of oil for a TD05H/TD06 up to 25psi or so of boost.....after that you can experience shaft scoring as the shaft loads will exceed the available amount of oil.

 

[knochgoon24]

This one never saw more than 22psi. I just turned the boost up yesterday afternoon. It had a little play before that, but not enough to worry. I drove almost 100 miles yesterday while doing pulls to get it dialed in and by the end of the night, the shaft play looked like that. Maybe a dozen pulls or so at 20psi.

I'll tear it down as soon as I can get something else on there just so I can drive it around. I friend may have a 14b to use, but I'm not sure. It felt good while it lasted though.

I was really hoping to get this to last until summer. Then it was going to be HX35 w/ BEP housing time.

 

[JusMX141]

Rip the CHRA out of the turbine housing and send it to me in a flat rate USPS box; I'll see if I can get it fixed up for you. I'd think it would at least make it until the end of the summer.

 

[knochgoon24]

Maybe I should head out and take it out now. I don't have a need to drive it for almost the next week. I can take the bus or bike to classes and work.