Mike's ST205 GT4 build thread, update: tuned to 200kw Options

[korban]

Man that's looking awesome, i'm so jealous.

That camera makes you pipes look purple but they're still blue right?

What boost is your wastegate spring set to?

Your boost controller should just have to open the wastegate earlier to stop the boost spike. Or your wastegate can't flow enough?

[delusionz]

According to Garret specs the wastegate is set at 12psi.

From what I've seen with a hand pump & gauge, the wastegate opens half way at 10psi and full way at 20psi.

Perhaps this thing would run at 12psi if I had like a 2.25" exhaust restrictor or something which could be one way to do it?

Looking down the inlet hole the wall by the wastegate tappers inwards thus directing the flow away from the wastegate and towards the turbine.

What I had done was the wastegate hole was overbored by 3mm, making the wastegate hole approx 1.5mm smaller diameter than the door itself. A path was also ground out in that inner tapper so that some flow is directed towards the wastegate. In addition to all this, the bracket that connects the actuator arm to the wastegate itself was modified (welded and redrilled) to bring the arm closer to the pivot point, thus allowing the wastegate door to open closer to 90 degrees instead of just a mere 45 degrees at full opening.

Now on wastegate pressure it seems to hold 0.9 bars, and 1.0 with my boost controller dialed into 1 bar - in all gears which is good.

The downside is I've lost ALOT of low end response, I'm hoping this can be remedied with a better EBC than what I have (HKS EVC 1) otherwise I think I've ruined was already a very perfect T28 housing (when paired to a factory size exhaust).

When I am able to tune this thing, and with that standard T28 housing rapid responsiveness boosting to 20psi on the tip of the pedal, I think I will get a fresh T28 housing to start over with again.

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Other minor updates:

Installed a stock black speedo surround as I was getting sick of the one I painted aluminum colour.

Replaced heater valve with item from 3s-fe Celica, as mine was brittle and chipped from running hot (probably should have bought new but this one seemed to be in good condition and still black and solid)

Run Bar's Radiator flush & rust remover then separately blasted out engine, radiator, turbo coolant lines, heater core and refilled with fresh Toyota LL coolant. (This fixed the heater just in time for winter )

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Still to fix:

Started having some weird electrical issues since the turbo setup and battery relocation, like headlights getting brighter when throttle applied, sometimes the starter motor when I turn the key does nothing.
Voltage test shows 12.5v when ign off and 13.4v when running at idle (which is what it should be right?)
I think I already know the culprits, I've had these issues on a previous battery relocation and solved it by running a separate ground from battery to engine in addition to grounding in the boot. - That and I had soldered every joint except the main power wire to the fuse box (the smaller wire) which I had used an audio crimp on, so I will solder this joint too.

Need a better EBC to dial my boost in better, one that controls the wastegate opening threshold too

Lots of bodywork repairs needed

Needs an oval muffler for the rear as it's way too loud.

This post has been edited by delusionz: May 27, 2011 - 7:17 AM

[opie_7afe]

if i can remember correctly alternator voltage should be at 14.4v but 1v lower MIGHT be the issue with your headlights...try this rev engine up untill lights brighten up and test voltage then (of course need another person) if voltage is 14 then it could be your alt. needing service, also check to see if the amps your alt. puts out is what toyota claims the alt. puts out...if every thing matches up to factory specs with the alt. then its your wiring some where.......double/triple check grounding points do the typical check of making sure its clean metal,not corroded ect, but your idea of running ground into engine is what should be done anyways when doing a relocation so id do that first see if it helps.....and if your starter starts doing a single click when you turn key..you just need to replace starter contacts/clean up plunger in starter....
good luck!

[johnyboy1976]

Great stuff

[delusionz]

Fixed voltage, turned out to be a bad solder joint on a major ground. Got 14.6 volts at idle now

[delusionz]

This post has been edited by delusionz: Apr 21, 2012 - 3:00 AM

[NZss1fun]

Looking good!!! glad to see u got all ur lil problems sorted NICE CAR! ooo waterspray huh GETTING SERIOUS NOW

[delusionz]

The update for today is ...

OZ Crono 16x8 ET38

[TRDGT4]

nice score

[Rusty]

hasn't won them yet...
looks nice, bit of curbing on 1

[delusionz]

Yea they're on the car right now, Just don't have a camera Lol.

A mate bought them for me to swap for my GT4 6 spokes, He loves his stock wheels lol

These OZ's are just a tad heavier, but still quite light

[delusionz]

They sit pretty damn flush too, OZ wheels 16x8 ET38 compared to stock wheels 16x7.5 ET45...

I've still got 15mm spacers in the rear, hopefully if these wheels dont rub my springs i can ditch the spacers, as i noticed during fitment that the wheels dont locate as perfectly on the spacers as they do on the hubs

Even though they are hub centric, theres still a couple mm of play you have to hold it steady once you have it straight and get a lug fastened asap

P.S. 205 tyres on a GT4 are f**king stupid, the idea of of a 4wd is to have massive grip, not to go sideways or spin the wheels every time you hit boost (on the up side, roundabouts are alot more fun now hahaha) So it looks like I'll have to get another set of 225 Toyo's

This post has been edited by delusionz: Jun 19, 2011 - 5:29 AM

[S8S8]

Nice choice of rim Mike.

Let's see some pics of them on the car.

[delusionz]

[Neon90424]

I have the same Fuel cut problem at the same revs man.

I will agree on the 225's and for some reason with the antilag I tried a launch yesterday on 225/45/17 and I got no skid at all and a damn great launch too.

Are you making the waterspray yourself?

This post has been edited by Neon90424: Jun 23, 2011 - 6:34 AM

[delusionz]

I fixed overboost by having the wastegate ported, its an internal gate on my turbo though.

Yeah same here, I've had now 205's, 215's and 225's on my car I'd have to say 215's were the best balance ...

225 = too much grip (it's too good, leads to alot of clutch slippage and no sliding around corners)

205 = pointless 4wd ... spins through 1st and 2nd in the wet, too much slide resulting in alot of lost cornering speed.

unfortunately they don't seem to make compatible 215's in a 16" size anymore

As for the water I'll get some more pics up soon, I'm using pressure spay nozzles, started with a window washer pump but didn't get enough pressure, Now have a fuel pump to try out ...

[Rusty]

dyno booked?

maybe look into the evc5, brother had it on his old S14 did a pretty good job

[Neon90424]

a 700$ boost controller? I bought an ebay one and it does just about everything that one does lol

[delusionz]

got the water spray nozzles are hooked up in the crash support bar, with 6 metres of 6mm blue silicone tube from the boot to the water spray nozzles, all wiring is tucked in and tidy with a relay and a button under the steering wheel.

using fuel pump with 2" silicone joiner to a custom aluminum tank being made up for me,

already tested by dropping the fuel pump in a bucket of water it works really well, dont even bother with a window washer pump a fuel pump is the bizz

[Neon90424]

I thought you were doing Water injection not water spray? why didnt you go CO2 spray?