Outer Limits 4x4 Board

When I first got my hands on my lux is was pretty shoddy, even with the line to the wastagate actuator totlally blocked I was lucky to get 6 pound of boost and 105Kph on flat ground.
Since then I have replaced and re-routed some of the old perished vacum lines and hooked the boost compensator up properly, replaced the injetcors and fixed the exhaust, had the radiator professionly cleaned (tanks removed and core rodded out to remove any blockages) with some small shims behind the wastegate actuator I was seeing around 11 pounds of boost, after tweaking the boost compensator's fuel delivery ramp I was over boosting to much and getting to hot (No I dont have a pyro, yes I am getting one ASAP) I was getting 12 + pound of boost.

Since then have taken all the shim's (washers) out from behind the wastegate actuator, this saw me peaking at around 9 Lbs of boost and able to maintain good road speed (happy to sit on 110 with enough acelleration to overtake reasonably safely) and not get to hot when under full load.

With this warm/hot weather we have been having I am starting to have overheating and overboosting problems again even on flat roads I am reduced to a safe road speed of around 100 to keep a lid on the temps when it's over 30 outside and the boost guage is sitting at around 10 psi and creaping up to 12 on full load..

The only things I can think of is that my wastegate actuator is playing up, the extra boost certainly not making any more power, if anything it feels a bit more sluggish.

I am new to the world of Turbo diesal's and need a shop that can help me got this sorted in north east Vic (wangaratta/albury area) .. or a backyard mech that can help .. I am happy to pay for your time and effort.

have you thought of fitting an intercooler (you could pick a small one up from an import wreckers, like a late model surf one, pretty cheap and get an exhaust place to do the pipe work)

Chris

yep definately want to do an intercooler , I notice how much quicker and torquier it is when the ambient temp is lower in the early mornings than in the arvo when it's in the high 30's.


Would adding an oil cooler assist at all with engine temps ?

yes oil cooler would help in lower temps slightly and intercooler would lower temps quite a bit, as a rule 1 deg lower in intake temp equals 5 deg lower in exhaust. if you want to lower your boost pressure try getting another lighter spring for the diaphram acuator. but I would recomend you get your pyro first and get a dyno tune as excessive exhaust temps are a direct result of over fueling. be it by too much fuel or by a restriction of oxygen. and since you have 12 pounds i doubt its the oxygen. If the engine is getting hot i would be checking other things aswell, such as viscus hub fan, thermostat, radiator air flow restriction.
my 75 crusier had over heating problems with the fitting of my turbo system, I removed and remote mounted my a/c condensor and it has been sweet ever since, thats with 18 pounds boost and a exhaust temp of 550 deg at full load.

love_mud wrote: With this warm/hot weather we have been having I am starting to have overheating and overboosting problems again even on flat roads I am reduced to a safe road speed of around 100 to keep a lid on the temps when it's over 30 outside and the boost guage is sitting at around 10 psi and creaping up to 12 on full load..

10psi on a flat road at cruise ???? it sounds like the motor is under large amount of load.

what exhaust sytem does it have?

the other thing the standard 2lt turbo is fairly poor at high boost, it tends to beat the hell out of the air making it hot. a lot of the boost increase could well just be caused by heat. a fair few surf owners have reported lower temps and better performance by 'hiflowing' the turbo.

could one of the cheapie ebay boost controllers not put a band aid over the problem for the meantime untill you can intercool and do an exhaust?

sierrajim wrote:could one of the cheapie ebay boost controllers not put a band aid over the problem for the meantime untill you can intercool and do an exhaust?

I need/want to get the turbo overhauled (uses a bit of oil through the seals about 500/700 mils per 1500 kms) I will do the exhaust at the same time, it's 2.25 inch from under the footwell all the way back .. The two exhaust places in wangaratta are useless (one will not tough turbo stuff at all, even though I told him I was happy to pay fro whatever time it took) or almost useless had a mix & match approach and had mix of 2, 2.25 and 2.5 inch tube in the exhaust.

I will take a look at the boost controllers on ebay as a start.

I have already pulled off the driving lights (Rallye 1000's) has not made a lick of difference to cooling/overheating. The radiator and A/C condenssor are free of mud/muck. I will check out the clutch on the fan as well (I would not have though that it would make alot of difference at 100 kph) and the temp drops rapidly as soon as I am off load (downhill run).

dump pipe and 2.5" or 3" exhaust. always do the exaust before upping the boost or fuel as the motor will simply choke on its own boost.

boost controller won't do anything if its overbosting. i assume you checked the waste gate wasn't stuck, otherwise you can be simply flowing to much exhaust for the wastegate to handle. if i remember correctly the cast dump pipe restricts the flow around the wastegate, need to research that again.

Waste gate moves (checked that this morning while motor was still cool) The state of the diaghphragm in the actuator is another matter .. will have to pull the compressor out from under the tarp and give it a gentle blow to see what happens

What I dont understand is that it was not overboosting then just appeared too without any noticeable/intentional changes to the motor or fuel system

pull the vac/boost hose off the wastegate actuator and blow into the actuator with your mouth, if you can blow air in then there is a leak there somewhere so the boost is leaking out and the wastegate not opening til late (if at all) i have 2 ct20 actuators both leak (one completely) i think the spot welds ont he bracket breack the can and theres the problem, sometimes the throttle cable rubs through them too as the sit on the side of the actuator.

that would also explain the sudden boost change.

bigcam wrote:pull the vac/boost hose off the wastegate actuator and blow into the actuator with your mouth, if you can blow air in then there is a leak there somewhere so the boost is leaking out and the wastegate not opening til late (if at all) i have 2 ct20 actuators both leak (one completely) i think the spot welds ont he bracket breack the can and theres the problem, sometimes the throttle cable rubs through them too as the sit on the side of the actuator.

that would also explain the sudden boost change.

Legend .. the actuator is stuffed ... (can blow through it no probs) .. where in Melbourne can I get a spare ... I would like to replace it before I melt a piston.

you should be able to pick one up from toyota if this is a common problem.. but expext a reaming. i think i have an old rx7 one here you could retofit, and i have a stuffed ct 20 one you could try and fix but welding it out cuz you will toech the diafram (spelling)

ebay maybe..

ill get the rx7 one out tonight and have a look if it can be fitted (have a spare turbo sitting there to see if it can fit, ill let ya know.
cam

mods delete this sh!T^^^^^

anyway the rx7 one is miles off but if you feel like fabbing something to make it fir then you can have it, give me a pm, obviously much easier to case an OE one down. the rx7 one is about 6-7 psi i think

cam

Thanks for sending me the wastegate actuator, I installed it last night..

Now that's working again I better get into installing a pyro..

I have heard heaps about where to install a pyro .. but I am stil unclear.. It seems the ideal place is pre the exhaust turbine (I guess that where most of the backpressure would be building up so that would give the most accurate reflection of the tempratures in the bores)

I will be removing the turbo/manifold so while I am at it I could stuff some clean rags in there and drill and tap the hole for the thermocouple (temp snesor) of the pyro ...

I have seen the VDO pyro's .. I would like a digital readout and if possible use a DIY aproach to making a pyrometer.. or am I better off just keeping it simple ...