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Old 11-10-2008, 01:24 AM   #121
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I really like your purple vacuum tubing
Road/Race Engineering gave us a box of used hoses they'd pulled off various cars they've worked on over the years. The purple hoses came from that box. Based on the color, I'm gonna have to guess they came from a 3rd-gen Eclipse...

The red elbow and red coupler came from my Silvia. The red was supposed to be color matched to the red-top SR20 valve cover. Didn't really work.

-D
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Old 11-10-2008, 11:27 AM   #122
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I dunno, it looks pretty close to me.



I'm still not sure i understand the reasoning for running the downpipe... down. there's gotta be something awesome about running a downpipe over the top of a convertible. right?
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Old 11-10-2008, 03:36 PM   #123
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We considered all downpipe options, including not having one, and settled on the layout you see here for a few reasons:
1. sound limits. If your car is too loud, the organizers black flag you and you end up making and installing a more sound-friendly exhaust in the pits while everyone else continues racing.
2. exhaust in the cabin. We didnt want any. At least, none from our own car.
3. I had a complete 3" miata exhaust half-buried in my backyard. Now I don't.
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Old 11-10-2008, 03:49 PM   #124
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Wow this thing is really coming together... Is there anywhere on the net i can watch a live stream of the race?
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Old 11-12-2008, 12:22 AM   #125
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Well, we figured some issues out (FMU hose routing; ground cables) and slapped on the ghettocharger setup. This car can't be driven on the street so all driving up to this point happens on the dyno rollers....

We've got 4 psi boost from 2000-5500 rpm, ramping gradually to nearly 5 psi at 6000 rpm. Perfect (for us) so far. Then it rises quickly, escalating to just over 7 psi boost at 7000 rpm. This last bit sends the fuel pressure off the charts... it pegs the fuel pressure gauge (100 psi is the top increment, and the peg is way past that). This is with 1.8 tan top injectors on our 1.6.

Our fuel hose has a max working pressure of 125 psi, so this is too much boost up top. I've since hogged out the wastegate hole a bit; we'll see if it helped.

Timing is base 12, bipes pulls 1 deg per psi boost. No pings heard yet. AFR hovers around 13.3-13.5 over the whole rev range (yeesh). I'd be more comfortable in the mid 11s but our options are limited since we're using band-aids.

This is my first exposure to an FMU car. Based on this, I'd guess the guys that run ~10+ psi boost using band aids have scary high EGTs and/or plenty of detonation... but if not, how?

Last edited by JKav; 11-12-2008 at 12:36 AM.
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Old 11-12-2008, 12:25 AM   #126
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Oh, and the fuel pressure still stays locked at 45 psi during all part-throttle (vacuum) conditions.. regulator overrun?
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Old 11-12-2008, 12:48 AM   #127
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Great to see it coming along! Are you guys basing the "over the top" turbo off of the "crx of death" from an old josh jacquot editorial? CRX of Death page
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Old 11-12-2008, 01:52 AM   #128
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Slightly more detailed update:

Quote:
Originally Posted by eyesoreracing View Post
1: pinhole leak in the brazing where we attached a -4 AN fitting to the stock Mexican Dodge oil line.
TIG welded. All good now...

Quote:
Originally Posted by eyesoreracing View Post
In naturally-aspirated form, the fuel pressure was running a near constant 47 psi. it should go down with manifold vacuum, but it didn't. It waggled around a little on transients, but didn't really behave correctly. A/F on the dyno was still a happy 13:1.
We hoped this was due to the bass akward Vortech, but no luck. This hasn't really changed much. We now have idle at 45 psi, WOT (with 0 boost) at 50 psi. Methinks WOT should be 43 and idle somewhere around 33. We tried swapping to a different stock fuel pressure regulator (from a 1.8) but no change.

Leading theory is that the big fuel pump is overwhelming the stock regulator, but we're open to others...

Quote:
Originally Posted by eyesoreracing View Post
We noticed the periodic idle stumble a couple of times, but not while we had the fuel pressure gauge hooked up. We're starting to think there's a relationship...
This is gone, though its not really clear what was causing it, I'm going to blame electrons.

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At one point (still before the fuel pressure gauge) the car died, and there was this strange thump-thump-thump-thump sound coming from under the car. Just before I turned the key off, Sarah spotted the fuel line pulsating in time with the noise.
Pretty sure that was the the backwards Vortech.


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Periodically there's a strange low buzzing noise that sounds like its coming from under the dash (only audible from the driver's seat) that corresponds with weak fuel pressure and a familiar idle stumble. I can best describe the sound as similar to bubbles rushing through a small, orifice. Yea, I know, no hydraulics or fuel lines under the dash, I'm just sayin that's what it sounds like...
Yea, so after fixing the fuel lines and thinking this problem was solved, I climbed in the driver's seat, bumped the brake pedal, and immediately heard the buzzing noise and saw the fuel pressure drop to 20 psi.

Rummaged around under the dash and found a relay making the buzzing noise. If you hit the brakes, the relay would buzz, the fuel pump would stop (or at least slow way the hell down), and the oil pressure gauge would peg (this was hard to spot, as it is almost always pegged anyway until you get a couple of dyno pulls worth of heat into the oil.) The turn signal would get a similar response, but less severe.

Turns out we had only grounded the engine and not the car, so the brake light electrons were finding their way home through the oil pressure sender, the fuel pump relay and who knows what else. One more ground wire and all was good.

Quote:
Originally Posted by eyesoreracing View Post
And, with the turbo in place, (and a bipes box installed and possibly wired correctly), fuel pressure drops to nearly nothing (10-20 psi) and the car dies as soon as it sees any load (like trying to pull off the lift and drive over to the dyno)
Ground wire fixed this too...

Oh, and we learned one more thing about freebuilt engines. They leak like a ****! Used gaskets...

-Dave
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Old 11-12-2008, 01:57 AM   #129
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Great to see it coming along! Are you guys basing the "over the top" turbo off of the "crx of death" from an old josh jacquot editorial? CRX of Death page
This old thing?



I have no idea why he put his turbo up there. Ours is up there because the manifold is free.

Plus, that hood, that bumper and those fenders are just slowing him down...

-D
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Old 11-17-2008, 02:45 AM   #130
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Finished the cross bracing on the turbo support bracket today;

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The supports on the exhaust side supports the weight of the turbo. The bracing from the intake side should limit side-to-side vibration. The mount is solid enough we could probably lift the engine with it. Only 24 hours will tell if its enough to keep the stock manifold from cracking...

-D
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Old 11-17-2008, 02:50 AM   #131
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We also made a new blockoff plate for the front coolant neck. The M16x1.5 nut is for the thermo fan switch. The 3.8 pipe is for an Autometer temperature gauge (salvaged from our CRX).

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We found another homeless guy to weld this one too.
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Old 11-17-2008, 03:01 AM   #132
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We also made this block-off plate to eliminate the cold idle bypass thingamajig. The valve was making injector swapping difficult, and the coolant hoses weren't getting along with the new addition to the turbo support bracket, so we just bypassed the valve and ran the coolant straight from the front coolant neck to the throttle body.


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Since we eliminated the idle air supply hose that normally pulls air from just forward of the throttle body, I don't think this bypass was getting any air anyway.

To make up for the lack of idle control air, we just cranked open the base idle bypass adjuster. It barely idles at cold start, but if you keep it running with the gas pedal for a minute or two, it's all ok once it warms up. Idle is abnormally high, of course, but we aren't planning to idle much anyway...
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Old 11-17-2008, 03:07 AM   #133
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And we kept burning ourselves on the hot downpipe, since its at such a convenient hand-resting position and the galvanized steel never seems to look hot. We finally figured out how to make it look hot...

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And in the background you can see another proud new addition. Blue silicone goo on the valve cover gasket. Hope to make the puddles smaller with that mod...
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Old 11-17-2008, 03:33 AM   #134
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Default Reducing dangerous horsepower

What's that? STFU? Less pictures of bad welding and more dyno charts?

Well, OK...

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Low 140s on 4 psi of boost. That's a 10% gain for every pound of boost. Not too shabby...

As you can see, air/fuel is damn near the same as it was before the turbo. This was scary at first, but after installing an EGT gauge and abusing the engine, exhaust temps peaked in the mid 800s (Celsius) which should be fine. All those rules of thumb about turbocharged AFRs are based on real boost, not this chickenshit 4 psi...

Backing up about a week, our first turbocharged pulls were a little scarier. Boost stabilized around 3.5-4 psi for a while, but around 5500 rpm, the wastegate would get overwhelmed and the boost would start creeping. Depending on when you finally let off the gas, boost could creep up to nearly 8 psi. Fuel pressure pegged our gauge (somewhere north of 110 psi) and AFRs stayed at about 13:1. All-around, not an endurance setup...

After that, JayKav busted out the die grinder and opened up the wastegate. He enlarged the port slightly and opened up the shortside radius on the inlet to the wastegate port, and smoothed out some nasty steps in the outlet flow as it headed out the downpipe flange. As you can see by this boost trace, we're now comfortably lame on boost.

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We're running 13 degrees base timing and the Bipes is set to pull 0.5 psi per pound of boost. In other words, we probably didn't really need the Bipes, but if we get greedy and turn up the boost some day, it will come in handy.
So far, we haven't heard a single ping.

Just to be damn sure the EGT we were seeing on single dyno pulls would translate to the track, we did a 4th gear track-simulation by running it to redline, dragging the engine down to 5000 or so with the brake, running it again, dragging it down again, and so on... We "datalogged" everything with the camera. Watch closely and you'll see a peak of 866C.



This was when we were running 1 degree per psi. Changing to 0.5 degrees dropped EGTs by about 20 degrees.

At this point, we're calling engine development done and trying to get the rest of the car ready for a track test.

Last edited by eyesoreracing; 11-17-2008 at 08:50 PM.
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Old 11-18-2008, 04:33 PM   #135
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Old 11-18-2008, 04:46 PM   #136
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You made it on Jalopnik!
Nice!
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Old 11-19-2008, 03:53 PM   #137
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Wow this thing is really coming together... Is there anywhere on the net i can watch a live stream of the race?
There are a handful of teams that *might* have live in-car streams...otherwise, Jalopnik will be running very frequent updates throughout the weekend. Keep an eye on our crappy website for live-stream updates.

And a shameless plug: Those of you who want to freeze your **** with us can pay at the gate to spectate--it's $20/day or $30/weekend.
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Old 11-19-2008, 04:06 PM   #138
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Dreamy.
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Old 11-19-2008, 05:47 PM   #139
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Do you get anything if you win? I'd cranked that boost up to 7ish for the last hour or so.

Absolutely awesome build. Good luck!
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Old 11-19-2008, 05:58 PM   #140
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Do you get anything if you win? I'd cranked that boost up to 7ish for the last hour or so.

Absolutely awesome build. Good luck!
A lot of nickles lol.
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