Jaemus's 5th SW20 - JDM 92 GT hardtop turbo

Re: Jaemus's 5th - JDM 92 GT hardtop turbo (Jaemus)

Thu, 05 Jan 2017 17:01:55 GMT

Peter
Hi Jaemus,
Your manual boost controller valve is an industrial instrumentation type valve, possibly a needle valve, which should give quite precise adjustment.
As you say it's not an automotive valve, but I don't really think that setting would alter easily.

Ahh, that makes sense, I did find it seemed very precise when I was blowing through it and adjusting the valve. Which is a super scientific test! Thanks for the info :)

5SGTE
Is it just me or do the plates look a little larger than normal? Like a 120% sized plate.
Either way 20OOT makes sense to me...

The plate is same as JDM size (you can see how it fits in the smaller JDM rear bumper cutout) but the numbers are much smaller, to match our local ones. Something about wanting to make sure there is nothing to stop the government continuing to strip cash out of us on the roads...

Knightrous
Number plates look like SOOOT to me, thought you might have done a Diesel conversion " />

Time to roll some coal?

Re: Jaemus's 5th - JDM 92 GT hardtop turbo (Knightrous)

Thu, 05 Jan 2017 09:49:34 GMT

Number plates look like SOOOT to me, thought you might have done a Diesel conversion " />

Re: Jaemus's 5th - JDM 92 GT hardtop turbo (5SGTE)

Wed, 04 Jan 2017 20:43:03 GMT

Is it just me or do the plates look a little larger than normal? Like a 120% sized plate.

Either way 20OOT makes sense to me...

Re: Jaemus's 5th - JDM 92 GT hardtop turbo (Peter)

Wed, 04 Jan 2017 20:41:49 GMT

Hi Jaemus,
Your manual boost controller valve is an industrial instrumentation type valve, possibly a needle valve, which should give quite precise adjustment.
As you say it's not an automotive valve, but I don't really think that setting would alter easily.

Re: Jaemus's 5th - JDM 92 GT hardtop turbo (robk)

Wed, 04 Jan 2017 17:34:33 GMT

Winning! Good work mate.

Re: Jaemus's 5th - JDM 92 GT hardtop turbo (Jaemus)

Wed, 04 Jan 2017 17:20:48 GMT

Dudeman
Now that you have owned a few, how would you rate each different engine type? You've had a beams, a 3vz v6 and now a turbo.

What's your favourite so far? And did the beams live up to its reputation?

It's hard not to love the turbo. The BEAMS car was light and agile and fun to scream around in, and the turbo is def a bit heavier, but it's far more smiles per mile as they say. I enjoy having the EHPS steering too. The 3VZ funnily enough sits somewhere in between but with the best soundtrack by far and the least effort to drive. It's good to have choices!

***
First of all, my new plates arrived.

While I like them, I'm not perfectly happy though because everyone seems to think they're meant to say 'toot'. Which wasn't the idea :P I was happy for that to be ALSO something they say, but the point seems to be being missed. Considering changing them. The idea, anyway, was the use the least letters and stick as close as possible to the japanese all-numerals xx-xx format without paying the RMS a fortune for 'full custom' plates. Using the letter O was the easiest way to achieve that and it makes sense with a 2000cc turbo engine. Right? No. Just 'toot' apparently. Too cute for my taste! :P

Fiddled around with the car a bit today in preparation for the MR2 Wakefield Park Challenge this month (in which I'll be competing, yay!).

It's been pinging a lot recently and the rather dodgy looking boost gauge I have has never read over 6psi, so I decided to investigate.

What I found was this;

- Ignition timing set to 25+ degrees of advance! WTF? Set this back to the factory setting of 10 degrees. Pinging gone! Still running 6psi.

- T-VSV looped off (fair enough)

- Vac hose from inlet manifold connected to > BPV (bypass valve or "blow off valve" (larger port). > BPV (smaller port) > connected to - get this - manual boost control valve. Then the output side of the MBC valve > connected to the wastegate control port.

Yeah, thats right, an aftermarket, inappropriate looking, manual boost controller valve with no bleed port (looks like this came from Bunnings?) connected to the BPV. WTF?

This made no sense whatsoever. The BOV was sortof working, but I suspect not correctly, and also this explains the (indicated) 6psi, which i think with a dodgy-boost-gauge-correction-factor of 1psi represented the turbo running at "wastegate pressure" - in other words, no boost control at all.

I also noted the BOV was missing the factory VTV (vacuum transfer valve) and appropriate hoses and tees, including the bracket to hold them. It's held that the BOV doesn't work properly without this arrangement, so I simply deleted the BOV from the control circut by looping the two ports together with one of the hoses. This created some flutter, which I'm personally fine with (remember GT-FOUR's don't have BPV's at all, and are the same engine and turbo).

I then arrange the MBC with one side going to the wastegate control port and the other open to atmosphere. I started tuning it with the valve closed and opened it in 90' increments whilst booting around the backstreets behind the local markets trying not to look like too much of a hoon, and observed a 1psi max boost increase for each 180' i turned the handle. I got to stock max boost of 10psi, no pinging :) Then I kept going to 11psi. I was aiming for 12, but it doesn't seem to go higher, and that's OK, as I was concerned anyway that the handle would turn on its own under vibration and cause overboost (i'll tie it off now). It clearly wasn't designed for an automotive application.

TLDR;

- Pinging, max boost 6psi
- Ignition timing was wrong @ 25+ degrees advance. Set to 10 degrees
- Boost control and BPV plumbing was all back-assward. Fixed
- Set to 11psi, no more pinging

Needless to say, it feels like a whole new car :) Realistically, it's basically still just at the stock level. But it was somewhere well below this before and I think this new arrangement is preferable for the upcoming track day, along with considerably less risk of engine explosion!

Re: Jaemus's 5th - JDM 92 GT hardtop turbo (Dudeman)

Sat, 22 Oct 2016 20:45:34 GMT

Jaemus
Thanks guys! I can't keep away from them for some reason

Have to say I am particularly loving this one. NFI why I didnt get a turbo years ago

Now that you have owned a few, how would you rate each different engine type? You've had a beams, a 3vz v6 and now a turbo.

What's your favourite so far? And did the beams live up to its reputation?

Re: Jaemus's 5th - JDM 92 GT hardtop turbo (Jaemus)

Sat, 22 Oct 2016 18:37:45 GMT

Thanks guys! I can't keep away from them for some reason

Have to say I am particularly loving this one. NFI why I didnt get a turbo years ago

Re: Jaemus's 5th - JDM 92 GT hardtop turbo (stuka)

Sat, 22 Oct 2016 14:46:54 GMT

car looks great, good to see you are still driving an MR2!

Re: Jaemus's 5th - JDM 92 GT hardtop turbo (Dudeman)

Sat, 22 Oct 2016 00:14:33 GMT

Highlander

It is just what you have to do if you want to be the Man in Dandism with the coolest aftermarket clutch.

Wouldn't that be the dandiest after market clutch?

Re: Jaemus's 5th - JDM 92 GT hardtop turbo (Jaemus)

Fri, 21 Oct 2016 18:24:39 GMT

Lol. My bad! I wrote that all in a hurry.

Falcon
You have been a busy lad.
I often wonder how many gearbox, syncro troubles are caused by that spongy worn out old pushrod and the nylon bush the clevis pin passes through in the clutch pedal. Well done. Bitch of a place to work too.
I've taken to making solid replacements.

Thanks! If you have a solid replacement you can sell me, I'll consider buying, as I dont know how long my welded up jobby will last :)

Falcon
Can you elaborate a bit more on the area in question of where exactly the problem was regards flywheel to crankshaft boss. Thanks.

I've drawn a patented high precision carefully dimensioned low tolerance aerospace grade engineering diagram for you:

I had to grind down the plate across about 4 inches of the rolled over edge of the in the middle where it was closest to the flywheel's crank boss mounting surface. I ground it back about 3mm and that did the trick, enough that the plate was still in one piece along that edge, just thinner. Should have got a photo at the time!

Re: Jaemus's 5th - JDM 92 GT hardtop turbo (Highlander)

Fri, 21 Oct 2016 12:37:08 GMT

Nik_Lee
Jaemus
Some more updates;

- Saved the best till last; had what i thought was huge difficulty bleeding the clutch. Spent most of a day pumping an entire bottle of coolant through it with a vacuum bleeder and it still wouldn't disengage. Then eventually found the clutch pedal clevis 'dampener' was worn out and was allowing the clutch master cylinder pushrod to bend upwards at the dampener instead of pushing it into the master cyl. Would never have thought to look at it!

I am sure this probably wouldn't have helped your peddle feel " />

All jokes aside your making some nice progress.

It is just what you have to do if you want to be the Man in Dandism with the coolest aftermarket clutch.

Re: Jaemus's 5th - JDM 92 GT hardtop turbo (robk)

Fri, 21 Oct 2016 09:31:49 GMT

Good work mate. I'm so happy to see the car back on the road!

Re: Jaemus's 5th - JDM 92 GT hardtop turbo (Nik_Lee)

Fri, 21 Oct 2016 08:28:29 GMT

Jaemus
Some more updates;

- Saved the best till last; had what i thought was huge difficulty bleeding the clutch. Spent most of a day pumping an entire bottle of coolant through it with a vacuum bleeder and it still wouldn't disengage. Then eventually found the clutch pedal clevis 'dampener' was worn out and was allowing the clutch master cylinder pushrod to bend upwards at the dampener instead of pushing it into the master cyl. Would never have thought to look at it!

I am sure this probably wouldn't have helped your peddle feel " />

All jokes aside your making some nice progress.

Re: Jaemus's 5th - JDM 92 GT hardtop turbo (Falcon)

Fri, 21 Oct 2016 07:28:59 GMT

You have been a busy lad.
I often wonder how many gearbox, syncro troubles are caused by that spongy worn out old pushrod and the nylon bush the clevis pin passes through in the clutch pedal. Well done. Bitch of a place to work too.
I've taken to making solid replacements.
Can you elaborate a bit more on the area in question of where exactly the problem was regards flywheel to crankshaft boss. Thanks.
PS. Most people don't use coolant in hydraulic systems. Innovative !