Pete Gossett (Forum Supporter) said:In reply to engiekev :
I'm thinking I'll just raise the idle :)
Now that is a GRM solution.
Pete Gossett (Forum Supporter) said:In reply to engiekev :
I'm thinking I'll just raise the idle :)
Now that is a GRM solution.
I finally got back out to the garage tonight to try & pinpoint the boost leak around the throttle body I identified last weekend. I was leaking a bit around the idle set screw, which wasn't too surprising considering how freely it turned, and more significantly leaking through 1 of the 4 TB bolt holes that I forgot to install & was waiting to pull the TB elbow so I could install it...
That definitely got rid of most of my leaks, and hopefully is at least partly to blame for why I never saw more than 10psi of boost. However, I have one more smaller leak I'll need to work on next, at the BOV.
Of course there's a good chance I'll discover more leaks once this one is fixed.
I think I finally fixed the power steering, and I'm an idiot for not thinking to check this earlier - the end of the PS pressure hose had a burr where it seats on the bottom o-ring. Once I cleaned that up, it seems to be holding ok.
I took the car for it's longest drive today, about 10-miles including a couple ramps. It ran surprisingly well, with no problems. I did notice it seems to run out of breath just over 5k, so I really need to check the base timing.
I've been working on dialing in the front alignment & it seems willing to turn without being too darty. I need to increase the rebound on the rear Konis a bit, but I'm not looking forward to pulling them off the car.
The shifter feels quite a bit better too. It's definitely on the stiff & notchy side, but the gates are much easier to find...except reverse. I'm going to try adjusting the cable a bit & see if that helps.
There's another autox next Sunday, so I'm planning on taking it over for some more seat time & tuning.
I had to work most of today, but got a couple small but annoying things checked off the list tonight.
The passenger's window wouldn't go down, nor would it go up quite all the way - there was about 1/4" gap. I pulled the door panel off, which was fortunately only held on with 3-screws & 2-clips lol, and hit the window tracks with some WD40. That's all it needed, the window works now!
Since the WD40 smeared all over the window I got the glass cleaner out, and since I'd forgotten to clean the windshield before the last autox I cleaned it too. It was pretty gross...
Lastly, I attempted to adjust the shift cables, since it still wants to grind when finding reverse. It was too late to start the car & try it out - I don't like starting it after 8pm since it's so loud - but I also tightened the pivot point on the trans slightly. If I get time tomorrow I'll take it to pay the water bill & see how it does.
Say hello to my little friend...
Under enginekev's guidance it was time to turn up the boost a bit. He said to set it around 15psi(vs. the 10-max I've seen so far), which would be safe for the current tune. Of course having no clue how far to turn it, I went about 1/4-way from completely open...and on the first pull hit 20psi so quick I didn't have time to lift. Damn, this thing makes a difference - not just in total boost/power, but in how much more quickly the turbo spools. I wasn't expecting that benefit!
I backed it off about a turn & after some more driving confirmed boost is peaking right around 15-16psi per the cheap boost gauge on the dash. I'm looking forward to being able to set it at 20psi eventually though!
In reply to Stampie (FS) :
20psi definitely puts it in the realm of one of the quickest cars I've ever driven, and I'm sure the quickest I've ever owned.
I uploaded the latest tune from engiekev & went for my longest drive yet. I should have set my trip odo, but it was probably 18-20 miles total.
The car ran well & the oil pressure was good most of the trip. I was mostly just driving it, though I did one 5th gear pull merging onto the interstate & backed off about 90ish. However, after I pulled off the interstate about a mile later I noticed my wideband controller continually reading "LEAN". The car seemed to be running ok otherwise, so I just babied it the rest of the way home.
Though the last 5-min or so at every stoplight the oil pressure would drop to 0. I'm not sure I trust this gauge, so I may buy an electric one to run in parallel for troubleshooting it.
Once home though I found the problem with the lean condition pretty quickly.
I apparently didn't secure the line between the MBC and wastegate well enough, and it ended up against the power steering pulley, which wore through it. All fixed now & I confirmed the wideband controller is happy.
A burn through on a waste gate line can get interesting in a hurry. Glad you noticed the wideband before hitting it and seeing moonboost.
In reply to 1SlowVW :
Fortunately, now that I know what 20psi feels like I think I would have noticed pretty quickly. ;-)
¯\_(ツ)_/¯ said:Is 20psi going to be your "hero pass" setting for the drags? More? Less?
Based on this compressor map, which should be close enough T04E-50, 20psi chokes at about 46 lb/min. It may not run all the way out to the edge of the map, so 400whp is a conservative estimate on power at 20psi. The turbo is rated for 450HP per turbonetics. The airflow values from the logs will tell us exactly where it's at on the map, but don't have any high rpm 20psi logs as we're working our way up slowly to make sure fuel deliver is dialed in and knock is minimal before going full send. If it looks good there's no reason it can't run 18-20psi safely on this setup. The "hero" boost may well be 23-25psi, which may be a bit much to handle on the autocross event, so 1/4 mile only!
This is a pretty old school turbo, but from DSM anecdotal times set to 25psi it can net 125mph 1/4 mile trap speed which should be enough to dip into the mid 11s with a decent 60ft.
We also have to dial in launch control (not too much to blow the drivetrain apart at drag strip conditions), that will make for a fun ride!
I've not posted any updates because I've been fighting an ignition problem since my last post.
The car had been running great, I drove it to the parts store & back on the 9th and everything was fine. About 30-minutes later I took my daughter & her BF each for a ride, and the car had an intermittent miss that I felt starting around 5000-5500rpm. I got some logs a day or 2 later & enginekev discovered the miss actually started as early as 4400rpm, but fortunately the AFR was good, so it's not a fuel starvation problem.
So I swapped in brand new plugs & wires, and was in the process of swapping coils when I discovered this:
That's the hot side of the coil, that also connects to the ignition module, ECU, and ignition switch. Fixing the bare wire, along with swapping parts, didn't really change anything - though it felt like the miss moved up in RPM a little bit - but we took it to the autox last Sunday anyway.
Despite running out of power too early & encountering the miss a couple places on course the car seemed to do ok, and my driving was much smoother. The power steering leak returned with a vengeance though, so we parked the car for our afternoon runs(again).
Since last weekend I've tracked down all the chassis grounds & confirmed I'm only reading 0.4-0.5 ohms on each on, and also on all-3 ECU grounds. I sent an email to ECMLink too, asking if they think the coil wire grounding out might have damaged the ECU. Let's hope not...
Lastly, I pulled the PS hose & banjo fitting from the pump tonight. I'm going to take them to a local hydraulic shop next week & see if they can give me any tips why it continues to link.
Which plugs and wires? These engines are very finicky about plugs and wires under higher boost levels. Regular cheap copper NGK plugs, BPR7ES if I remember correctly (one range colder than stock.) Never had any luck with fancy expensive plugs with this engine. For plug wires the stock NGK are good. I’ve never had luck with aftermarket wires, all short life or bad right out of the box. Magnacores used to be popular for these cars, despite the fact that many were crap right out of the box. Funny story, I had a fresh set of aftermarket performance wires on my old Talon. I remember noticing a miss the morning that the car was totaled by an 18 wheeler. That’s not the funny part. I scraped the car and saved anything that wasn’t destroyed in the crash. I put The still new looking plug wires back it the box and stuck them with my Galant VR4 project car parts. Finally got around to finishing the VR4 years later, and used the wires. Had the same miss that you described, didn’t think to check the wires because they were “new.” Somehow remembered years earlier that the Talon had developed the miss before it died, swapped the wires for stock NGK’s and all was well.
The turbo that you are using, it sounds sized pretty closely to a 20G? I’ve been running 20psi in my VR4 for years, with a 20G and stock long block. I think it’s a pretty safe setting if the tune is decent. Actually ran it like for a long time with no real tune at all- just an Evo MAS and 780cc injectors that pretty much cancelled each other out, and and old school Super AFC. Nothing near as advanced as what you have. I’d consider 20psi the baseline, and go up from there, it’s no where near hero pass level.
In reply to Boost_Crazy :
Thanks!
The car came with NGK wires that looked nearly new, but I grabbed the only set (of cheap parts store) wires in town to troubleshoot with. I tried a new set of BPR7ES plugs too.
I have the rear shocks pulled off now so I can crank up the damping a bit & try to find a way to lower the springs another inch. I also may have a solution to my power steering leak.
I took the pressure line & banjo fitting to the local hydraulic shop today. He checked the 2 o-rings & said they're a softer durometer than he typically sees in uses like this, so he gave me a pair that are 90-durometer.
Once I get this stuff done I'll go back to trying to get it running well again.
My friend Rod stopped by today, but I didn't answer when he knocked...
So at this point I'm going to push the car into the back corner of the garage again & wait until the weather cools off to pull the engine. I'm going to take it to the machine shop who did the head & let them figure out how to remedy this so I won't have any problems for quite a while. That likely means I won't be bringing the car to the Challenge, which sucks, but I was already looking forward to post-Challenge plans for it anyway.
Despite it being 800-degrees hotter than berkeleying hell today, my step-son was off work so he came over to help me shuffle cars around in the garage again. No pics, because the garage looks just like it did back on page 2 or 3...
However, I started the Miata up for the first time since February. I was a little surprised it started, even though I'd left the battery disconnected, but there was no drama at all. I left it idling while we got the DSM back into "service position", cleaned all the spider webs out from under in inside the Miata, and took it for a spin around the block. It's funny though, because obviously with 1/3 the HP it's laughably slower than the DSM, yet it doesn't really feel slow? It's such a more solid & better built car too. Someday I may have to decide which one of them to let go, but thankfully not today.
This is how all dsm adventures go I think.
1. buys dsm. 2. has to fix junk from PO. Also turns up boost. 3. is pretty sure its the fastest car he's ever owned. 4. Knock knock. Who's there? 5. Big turbo build, that's who.
Oh yeah, when I drove it last weekend the PS was still leaking & it still had the high RPM miss, so I have that to look forward to once the bottom end is fixed.
Power wise I think 400hp is about the right number for autox. Any more than that and I need to spend $$ on the trans & axles. And if I get to the point of lighting fistfuls of cash on fire & throwing them at the car I'll be looking at a CF hood too - I swear the stock one must weigh 80 pounds.
With the oppressive August heat I've only been working about 15-30 minutes at a time, and not every day, but I am getting nearer to dropping the pan. I need to lower the exhaust, pull the transfer case, and then I should be able to pull all the pan bolts.
Oh, and there was no cotter key holding the driver's side axle nut in place, so thankfully it didn't decide to spin off. I'll be checking the other 3 though.
The weather finally cooled down to slightly below "insufferable" so I finally pulled all-4 rod caps to investigate the knock I discovered a couple weeks ago. These are in order 1-4 top to bottom. Obviously 1 & 4 are trashed - of course I only pulled #2 when I replace the head gasket... Does this damage look like it could have occurred in 50-miles/2 autocrosses, or was it likely from the HG putting coolant in the oil?
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