got the gauges wired and the boost gauge plumbed.

Haven't had chance to fit the oil temp and pressure senders yet, but main illumination/backlight wiring is in+the oil gauges wiring is in and the boost gauge is plumbed.

Took it out for a spin, and once nicely warm on the stock coolant gauge,

5-6 PSI in 1st and 2nd.

and then in 3rd and above, peaking at between 8-10PSI, dropping off to a steady 7 1/2PSI (ish) on the gauge (it has a 5psi a 10PSI marking, and a dot inbetween, it holds dead solid on the dot).

In 3rd it hits 8 peak, in 4th and 5th it hit 10, but dropped back quicker.

Does that sound about right for a dead stock 185 with 143k miles on the clock with just a cone filter and a dump valve in the way of engine mods.

Reply to
Sleeker GT Phwoar
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Bugger, must have knocked a wire loose, they light up OK, but they don't dim when the lights are on.

Not a major deal to worry about.

Reply to
Sleeker GT Phwoar

Are these the funky back lit ones from the states?

Reply to
Depresion

Why is it peaking higher than it holds, and why is it making different boost in different gears ? Providing the engine is under max load, then once the preset boost level is reached it should just sit there. There should be

*very* little spiking, if any. Have you got some dodgy ECU boost program, that's limiting pressure in the lower gears ?
Reply to
Nom

Yep, will try to get some photos probably at the weekend.

Reply to
Sleeker GT Phwoar

The Saab used to boost upto 13PSI, and droop back to 11 after so many revs. Quite normal to have a peak level and hold level. I think the variations in the peak is because of the boost holds better with the taller gears. But I've noticed that power really falls off above 5.5krpm becaus of the very restrictive CAT. Vamp will probably tell you the same.

I've noticed that the Saab did pretty much the same thing, it would pull harder from lower revs in 4th and 5th than 3rd, and hardly do anything in 1st and 2nd, and drop boost a little at higher revs. The Saab also had a very restrictive turbo elbow.

Toyota use the T-VSV to set the wastegate low, and then hold it closed using a vac feed operated by the ECU. So they can have low boost in low gears to cut down on wheelspin, and protect the box, and full power (artificially held) later in other gears.

Nope it's factory. but the plan is to disable the T-VSV so I get standard low boost in all gears, then fit either an MBC or EBC, and dial in a set boost limit, probably peaking arround 11PSI for all gears. Should spool earlier and not run out of puff in the higher revs, once the Decat pipe is fitted too. Smoother bends in a slightly bigger bore, and no rstrictions.

Reply to
Sleeker GT Phwoar

taking out the VSV is something a lot or MR2 turbo peeps do. ditch the VSV, fuel cut defencer, boost whacked up to 14PSi using an AVCR or a manaual boost controller, decat and a boost gauage to keep an eye on things should see 280bhp easily.

my MR2 works different i think as i think the MR2 gives full boost in all gears which can be shit scary in first :-P but it's fun like that :)

may looks at messing with it later but for now the standard 220bhp is fast enough for me, plus i lose a bit of torque with a decat i heard and i like the low down grunt it has at the moment. can outrun a lot of things hardly trying anyway :)

Reply to
Vamp

Quite probable mate, especially with yours being an import, it may have been de-restricted before it hit the UK.

You will only lose torque if you take the exhaust bore above 2.5". You only need a 3" exhaust if you are above 300BHP at the flywheel, and are already running a bigger turbo or stage 3 hybrid CT20/26.

Lucky bugger, only have 205BHP. Must free up som power now I have a gauge to make sure it isn't spiking.

Reply to
Sleeker GT Phwoar

205bhp and 4WD so lose some power in that too hehe.

weird though, must be well restrictive only having 205bhp that's 15bhp down from mine! mine has the standard exhaust and i quite like it, probably get a mongoose fitted if and when it brakes with decat pipe as it looks like the original which i like.

going to try and find someone with an MR2 turbo whacked up to 280bhp at a meet one day and see how different it feels, most the MR2's i know are running 300+ although i have been in a 270bhp rev3 MR2 turbo thinking bout it a while back and that was DAMN quick!

stop it carl stop it! i'm trying to save cash without thinking about modding the motor! :)

Reply to
Vamp

Crimp connectors are shit. Solder it.

Fraser

Reply to
Fraser Johnston

It would be great to solder it if I had electricity anywhere near the car, or felt brave enough to attempt to join 4 bits of wire with a propane flame, while they rest near the plastic trim with it's loverly vinyl covering. If it has come loose, I'm going to use a lego/scotch block temporarily.

Reply to
Sleeker GT Phwoar

I soldered my pillar gauges. I got a flameless propane soldering iron for less than 10 quid. I also used heatshrink to make sure they would never arc out on anything. Scotch locks should be banned in my opinion. Evil evil things.

Fraser

Reply to
Fraser Johnston

You need a gas powered soldering iron.

They cost almost nothing, and run on lighter-fuel. You refil them by just ramming the aerosol into the base.

I've got one - works great !

Reply to
Nom

Only if whatever is limiting the boost, is shit :)

Spiking is normally associated with bleed valves and the like. If your ECU is using a solenoid or similar to control boost, then spiking should be minimal if any.

At the levels you're running, it's no problem. But imagine if you'd tweaked things upto 15psi - the extra 2psi spike may well be enough to pop the engine.

You'll only make maximum possible boost when the engine is under full-load - but I found in the TI that you could achieve full load in every gear except

1st (for obvious reasons in a FWD car :)

Yeah, Rover did the same sort of thing, but it applies in all gears. Wastegate is set to around 6psi. ECU controls a solenoid that raises boost to around 10psi. It lowers the boost slightly in the midrange, to prevent the engine ever making more than 240Nm, for gearbox life reasons. Remove the solenoid and replace with a ball-bearing-against-a-spring valve to remove the torque limit, and preset the boost level to 12psi, for a nice torque boost right through the ranges. Your right-foot then becomes the torque limiter - obviously hard acceleration in top gear from 30mph isn't really a good idea etc.

Reply to
Nom

The one in my car boot runs off 12v.

Came in v. handy once, well, a different one did, many years ago, but it's all the same idea. Sommat in the distributor went bang on a deserted stretch of a long motorway in the west country, and the engine died. Took a while to find the sooty, broken wire in the dizzy, but then cut something off some other part of the car, and soldered it in instead, which held up fine, at least for a couple of years until the car went west.

Reply to
Questions

That is the plan, hence why I've replaced the intake hoses with decent silicon ones, replaced as much VAC hoses as I can get to, and fitted a boost gauge.

Either a fixed set manual boost controller, or a decent electronic adjustable solenoid one.

Biggest problem a lot of the GT4 guys have had with boost controllers of any kind is, if they go for a 3" decat and exhaust, they get boost spikes. they find they need to make a restrictor plate at 2.5" and fit that between the Decat and the system, they get most of the benefits of the 3" system without the spiking. If they go for more extreme tuning (different turbos etc) and are looking at over 300BHP they can make a

3" system work without spiking, without needing a restrictor.
Reply to
Sleeker GT Phwoar

damn GT4's aint simple are they!

MR2's don't seem to get the same issues which is weird. but then our exhaust system is half the length of your GT4 :)

Reply to
Vamp

Yep, that's the way to go. They aren't fixed by the way - you're free to adjust the level by twiddling the screw !

Complete waste of time and money. And will lead to spiking. Avoid.

Then their boost controllers are s**te or electronic or both.

The only ones that really work *well* are the ball-bearing-against-a-spring type :

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Don't bother with anything else !

Reply to
Nom

sure there is a guy on imoc that sells these for next to nothing, i'll dig his details out if you like mate as i think he does a few GT4 bits

Reply to
Vamp

Yeah, they cost nowt. Mine for the TI was £20 if I remember correctly, and it was the Mk2 model with a ceramic ball inside, for apparently quicker response...

Reply to
Nom

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