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BLOZ UP


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I'm curious if that fluttering when you get off it is just your BOV, or if you are stalling the turbo. It sounds like you might be surging, but I'm not sure.

 

It's surge. It also, in all of those videos, was surging at "full" throttle. Upon further investigation I had adjusted the cable incorrectly and was only getting 75% throttle.

 

So instead of the 17.5 psi that I thought was full boost, on a 14psi wastegate spring, I now have 20.5 psi. So, I have no traction, I don't think I have surge now at WOT... but it came on quite strong and I wasn't really paying attention to the sounds of surge, if any.

 

It also surges really easily during shifts. The BOV appears to be a little tight. It takes quite a pressure difference to open it. I think I might try and remove a coil or two and see what happens.

 

So, it's down at the moment while I take apart the wastegate and see if it needs a rebuild, and for a 8psi spring regardless. I'm also adding a flex pipe to the secondaries after finally finding a properly sized high-pressure flex joint. And some heat shielding and other things while I am there. It might be a little louder when I'm done.

Edited by BLOZ UP
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  • 5 weeks later...

Wastegate: new spring

Boost controller: fixed (I think)

Flex pipe: added

Lost sync issues: came and went (fixed--so far)

Wideband: died and replaced

Problem where engine would cut out: looked at gas gauge and filled up.

Cruise tuning: almost done

 

Here's the most recent footage:

 

http://www.youtube.com/watch?v=8wH3GeLrxu4

 

 

f836e62.jpg

 

 

 

806c761.jpg

 

Next up:

Seafoam and an oil change to try and quite a lifter.

Turbo support brace

Catch can

Dyno run

 

Not necessarily in that order.

Edited by BLOZ UP
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I forgot to ask, and didn't see it while glancing back over your previous posts, but are you using a 71C (n/a) trans, or the turbo borg-warner t5? I've got a 71C lined up under the car now, positioned about the same as you have shown, but looks like the mounts aren't quite spot on compatible as what your pics show. Nothing that can't be fabbed; I was just curious as to which trans you were using.

 

Cheers,

 

JK

 

I'm using the 71C. I used the 300ZX rubber isolator over the 280Z crossmember.

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  • 2 weeks later...

Engine compression test, im guessing that somewhere around 150-170 psi would be ideal for that motor, check the a/f ratios and ignition timing. Make sure the injectors are clean and balanced?

Edited by Meph
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Last compression test was 120psi on all except one at 90 and one at 110. I had just put the injectors back in after cleaning the day before (more info on my website), and had tuned it very very roughly on the way to the dyno. I had a decent map from before but I richened it all out. The last two runs (12 and 18psi) bottomed out my LC-1. Timing is also conservative.

 

Basically, the motor needs a rebuild. I knew this ahead of time, but I didn't think it was THIS bad.

 

 

e67d0ae.jpg

 

 

c722552.jpg

 

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The engine compression being so low is going to cause some loss is power, my 8.5:1 engine with a rebuild has aroud 180 psi, say you could contribute a 15% loss due to a worn engine (I really have no idea what the % would be but I think 15 is conservative) and an A/F ratio thats so rich is looks like a diesel truck + safe timing you are probably looking at another 20% loss of potential power. I've been working on my maps for a few years now just tweaking the boost injector timings on the street and slowly but surely Im getting there, its an excuse to drive the car every day :) Im just aiming for 11:1-12:1 a/f in boost, when you have something like 8:1 or 9:1 A/F you loosing a lot of potential efficiency. So 240 x 1.35 = 325WHP = about 375HP crank. seems like a nice number to me

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Well we can speculate all we want. What matters to me and my iEgo are the actual numbers it puts down. And right now I'm getting 5mpg and don't have any power to justify that with.

 

But it looks like I might pick up a 9:1 low miles maxima motor soon. Need to get one of those leakdown testers to be sure. Remind me to do a test on both new and old engine--then we could even get a realistic % assuming the current tune works well on the new motor.

Edited by BLOZ UP
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I built a leakdown tester with a regulator from lowes, some fittings, and a hose from a compression tester. It works beautifully, basically you make an orifice between the regulator and the cylinder, set the pressure before the cylinder and measure the pressure in the cylinder. It will be less because of the restriction of the orifice. Say you set the regulator to 100psi and you measure 90psi in the cylinder, that's 10% leakdown.

 

After using one, I wouldn't be without it, I had similar compression numbers, but between 30 and 70% leakdown on my old engine, the new one is 8%.

 

This is pretty close to what I have, it's WAAAYYY better than the HF one I tried. http://forums.evolutionm.net/evo-how-tos-installations/481133-how-make-your-own-faa-spec-leakdown-tester.html

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Meh, I got the Harbor Freight one. I picked up the maxima motor. I'm in the process of getting it on the engine stand and I'll attempt the leakdown from there. I tried to do it at VGs To Go, but it kept turning over on me. Also have a bunch of new seals.

 

I might have it in by this weekend. For sure by the end of spring break.

 

I break in my engines by racing.

Edited by BLOZ UP
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I wanna go for a ride in your car. I have seen it like 10 times now and still haven't even sat in it. Hurry up and swap!

 

I had to order a new starter for my 73 240zt but at least I got the computer to recognize everything where I can actually tune on it. After I drop the new starter in next week im gonna go get in trouble :)

Edited by MrCleburn
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My engine had to be dead on TDC in order to not turn over. Good luck with the swap, my school starts back up monday. :( Break in for me lasted about 20 minutes, then I started beating on it, I didn't turn the boost up for a few hundred miles though.

 

 

Your car looks GREAT by the way!

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I wanna go for a ride in your car. I have seen it like 10 times now and still haven't even sat in it. Hurry up and swap!

 

I had to order a new starter for my 73 240zt but at least I got the computer to recognize everything where I can actually tune on it. After I drop the new starter in next week im gonna go get in trouble :)

 

So what was with the computer? Wrong INI/config file?

 

Meh, the interior needs some work. Seats are all torn and bad. I have the interior pieces and a new carpet. Just been too lazy and focused on powah.

Edited by BLOZ UP
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  • 2 weeks later...

Hey are you going to that drive in thing saturday? I wanted to see if I could go and meet some of the cowtown z club.

 

That's a very good question. I am working on swapping a maxima motor in. I have all the supplies, and I'll have some time friday and early saturday. It shouldn't take that long... but I have my doubts. I might go in the daily if I can't finish.

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That's a very good question. I am working on swapping a maxima motor in. I have all the supplies, and I'll have some time friday and early saturday. It shouldn't take that long... but I have my doubts. I might go in the daily if I can't finish.

 

lol I don't want to just show up and not at least know anyone from the forums. Get that engine in and lets go.

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