Reliable gen 1 3sgte at 11psi?

[RWDboy]

Mmk now as for the cooling system, well there are reasons *why* Toyota run the pump in bursts every few minutes.

The heat exchanger itself is quite small, and can only effeciently cool a certain amount of water over a given time. I think you'll find that running the pump constantly will merely cause the heat exchanger to have alot of hot water flow straight through it, it may do little at all to improve heat exchange to run it constantly. I can't exactly say whether it will make it better or worse, in most situations I would expect to see some improvement due to there being a more constant difference in temperature (thus promoting the heat flux). Probably the best solution (the route I'm taking) is to back off the flow rate of the pump, have it run constantly and run a larger heat exchanger with better air-flow directed to it.

The air going through the intercooler is quite hot, for sure, but the specific heat of water/coolant is such that it will take some time for something as inefficient as the standard core to heat the volume of water up - if you are driving hard around, say, a circuit then 30 seconds every three minutes isn't going to cut the mustard, but then neither will the standard heat exchanger in most circumstances.

[-=DV=-]

man speaking from experience, the pump running full time does make a difference, a huge difference, thats why i suggested it, the stock system aint that bad for stock boost in favourably cooler conditoins (definately not the hot dry SA outback ), anything over stock boost and its just hopeless, when i was running 15psi i had problems with both radiator coolant and the w2a coolant boiling, problems gone with frontmount though lol

~edit~
ill add that this never happened at 12psi, and only at 15 in the hottest parts of summer. guess with it now being winter theres really no way to see if it still does it after frontmount, but everything seems to run incredibly cooler after the fmic setup went in, engine bay heat is down a rediculous amount, the radiator is alot more efficient and yeah.

rwdboy sorry if u got the impression i was having a go or anything man, it just gets under my skin when *most* ppl say gen1s are poo, the last thing u want is a gen1, blah blah blah most of these ppl have never owned one, and seriously, im not kidding when i sayi have seen and heard of ALOT of gen2s dieing with less punishment and less miles than similarly treated gen1s, i just sorta get really defensive because the gen1 is an incredible motor for its time and age, and with all the revisions and that made in the gen2 they make only the slightest more power and for some reason seem more prone to failure, in my experience with gen1s, and what ive heard of alot of gen2s. although for every dead gen2 out there, theres probably 1000 to prove me wrong, but the same scenario goes for ppl that bag on gen1s aswell.

[JustenGT8]

I'm with DV on this one. Admitedly i'm talking about the 185 and 205 a/w ICs but the principles should be the same...they also do have much better heat exchangers than the 165 but again the same physics is in play.

Regardless of how pisspoor the HE is running water thru it constantly still results in the system sheding more heat than an intermittant flow. Simple conservation of energy, it has to be somewhere so if the pump isn't flowing it's being stored in the coolant. Could be it reachs some state of equilibrium where the mass of non flowing water can't adsorb any more from the intake charge but in the real world the differences are like chalk and cheese.

I have some empirical data somewhere of my before and after and there's some elsewhere on the web but just the touch test was enough to show a HUGE difference between the intermittant and constant.

On the 185 and 205 at least the pump is virtually constant anyway...it turns off after 30 seconds of less than 15% throttle input from memory (don't quote me). The reason Toyota did this is to save on pump life as for most drivers the ultimate performance from their car isn't the be all and end all like it is for us modders.

Another factor to consider is that when off boost the actual IC sheds heats into the intake charge (if the differenetial is there which it usually is) so by keeping the flow going you effectively have 2 HE in action keeping you coolant cool and ready to go for when you need it.

[trd-st162]

From this then, I'm sure a gen 1 3sgte with the pump mod would be save to do 9-10psi.
There is little lag on the exhaust system, the air intake has been done and the intercooler is runnin the pump mod.
If we were talkin reduced turbo life, on the odd occasional spurt driving how long would a good nick ct26 last compared to runnin 9-10psi?

[RWDboy]

I'm with DV on this one. Admitedly i'm talking about the 185 and 205 a/w ICs but the principles should be the same...they also do have much better heat exchangers than the 165 but again the same physics is in play.

Regardless of how pisspoor the HE is running water thru it constantly still results in the system sheding more heat than an intermittant flow. Simple conservation of energy, it has to be somewhere so if the pump isn't flowing it's being stored in the coolant. Could be it reachs some state of equilibrium where the mass of non flowing water can't adsorb any more from the intake charge but in the real world the differences are like chalk and cheese.

I have some empirical data somewhere of my before and after and there's some elsewhere on the web but just the touch test was enough to show a HUGE difference between the intermittant and constant.

...

Another factor to consider is that when off boost the actual IC sheds heats into the intake charge (if the differenetial is there which it usually is) so by keeping the flow going you effectively have 2 HE in action keeping you coolant cool and ready to go for when you need it.

Okay, all I'm trying to say here is that modifying the pump to run constantly on an ST165 will do very little but reduce the life of the water pump. It will make a very very marginal difference to overall cooling efficiency, so marginal that I personally wouldn't bother unless I was going to change the heat exchanger system significantly. The 'physics' that you are referring to is completely ignoring what is the biggest limiting factor in any water-air cooling system - and that is the ability for heat present in the water to reach the surface of the heat exchanger and then get carried away by the air (heat flux). The ST165's heat exchanger is so very very small that pumping more water through than what is done stock will do very little to improve overall efficiency of the system, especially in daily driving conditions (race conditions are VERY different).

Also touch tests aren't exactly the most scientific of methods

[JustenGT8]

Agreed a touch test may not be the most quantifiable of tests but if before it's HOT and after it's COLD then you don't need a thermocouple up your arse to pick that difference ;-)

As i said, i am relating my results with the 185 and 205 a/w IC's. I would have thought the 165 would be pretty similar but happy to bow to your experience with them. Sounds like the priority is to get a bigger HE in there but sounds like the best option is actually FMIC?

[wiso]

The car has always been driven on 95 octane..
I honestly haven't seen one single problem, doesn't ping or anything,
and has been driven with 95 even on 11psi.

I'm quite curious to just set and leave at 11psi, obviously to just leave it as is i would be driving quite sensibly off boost and not always full throttle,

Thank you very much to everyone,
My only query is related to the actualy fuel i'm runnin!

ahh wrong, i only ever ran it on 98 octane fuel, i never put 95 in it, 95 was before the 3sgte swap. i used optimax but thats becuase back when i was running this car, that was the only redily available in canberra, if i had my choice now it would be mobil synergy 8000 or bp ultimate,

dunno why you are soo adversed to running 98 its onyl an extra $3 for a full tank, $3 a wekk extra, is it that hard to afford?

[-=DV=-]

From this then, I'm sure a gen 1 3sgte with the pump mod would be save to do 9-10psi.
There is little lag on the exhaust system, the air intake has been done and the intercooler is runnin the pump mod.
If we were talkin reduced turbo life, on the odd occasional spurt driving how long would a good nick ct26 last compared to runnin 9-10psi?

fuck dude i dont mean to sound rude but stop being a pussy and either do it...or dont and stop asking questions about it..its only a boost increase, its not like ur trying to decide on what turbo to use for ur next project, you have allready been told the engine will handle it, u have allready been told the i/c system can keep it cool enuff to be a performance increase and still safe, you have allready been told it wont make much difference to the turbo (eg my turbo was allready dieing over a year ago when i upped it to 12 psi, its still powering on, still slowly dieing) the only thing u have to worry about is going over 14psi if you happen to have a ceramic wheeled turbo, wich i doubt you do. seriously man not to be rude, but its only a boost increase. if your that scared it might hurt ur car in some way, maybe a turbo'd performance car isnt right up ur alley?

[trd-st162]

hahaha DV,
I've had so far 3 opinions on it hahaha.
Urs was "15psi will be ok still with a FMIC"
RWD Boy mentioned he knew of some significant problems and justin gt8 mentioned it would be ok,
I take good care of the car and wanna make sure i won't stuff up something that i can prevent..
I gave u good rep for ur comments and this is how u repay me? LOL
Thanks anyway!

[-=DV=-]

i also mentioned piggys 165, he lives a few streets from me, he is running 12psi without a problem, and mines only had a frontmount on it for the last few weeks, but been running 12psi for over a year with no problems. and if they arent enuff examples just look at it this way, toyota play it ultra safe and conservative, would they let it boost to 9-10 psi if it was harmful for the engine? no they wouldnt. ur basically asking if running a level of boost lower than what the manufacturer has considered is safe....is safe? seriously man. its once u start playing with fcds and start going PAST what toyota have considered safe that you start asking the questions "what will this damage?" "how long will this last?" which even then are almost impossible to be answered anyway because they arent a common engine, not enuff ppl have owned them and killed them under stock and modified circumstances to make good comparisions on howmuch more wear and tear X action will put on Y motor.

and once again, its ONLY A SMALL BOOST INCREASE...why do u need a million opinions and life stories dude, sorry man but like i said, if its not fuel cutting its safe for the engine, if it is fuel cutting its still safe for the engine, but bloody annoying.without an fcd, or standalone management, you cant give these engines enuff boost to damage them...end of story.

[-=DV=-]

after re reading the thread, i didnt see me mentioning piggys, must have been another thread i mentioned it in, anyway piggy owns an st165, gen1 3sgte, he runs 10-12psi without problems, so far thats me,and,jorrs that have told you from experience these engine/turbo packages are reliable at 11psi to add that, piggys is also problem free at that level. theres no need for the thread to go on like 2 pages, u asked if they will be reliable at that boost, and u got examples of reliability at that boost, ontop of that as mentioned the fuel cut is there to stop u pushing far enuff to damage the engine, if it was unsafe to run 10ish psi the fuel cut would be set before that wouldnt it.

[Jorrs]

watcha doin harley ?? u not on msn

igot pics of my fmic i wanna get

[-=DV=-]

lol u musta posted that just as i got on...was on another msn account lol

[oldcorollas]

just a bit of science for the pump running all the time..

the higher a temperature diferential, the faster heat will be transferred at the interface.... which is why something will cool quickly from 1000C and then slowly from 100C...

if you run the pump all the time, you will maintain the highest temp possible in the heat exchanger, which increases IT's efficiency. you may not drop the temp of the water as much as if you leave it sit there for 3 minutes, but you physically lose more ENERGY from the system, because you are maintining a higher temp diff, and thus higher flux of heat.....

there may be an upper limit of flow rate to allow transfer of heat from the fluid incontact with the walls and the centre of the channels, but i very much doubt it is reached in the stock system.. this would be identified by a HE exit temp being similar to the inlet temp.

and of course the opposite is true for the interwarmer... you want the lowest inlet temp to have the highest temp differential....

meh, anyway

[RWDboy]

just a bit of science for the pump running all the time..

the higher a temperature diferential, the faster heat will be transferred at the interface.... which is why something will cool quickly from 1000C and then slowly from 100C...

if you run the pump all the time, you will maintain the highest temp possible in the heat exchanger, which increases IT's efficiency. you may not drop the temp of the water as much as if you leave it sit there for 3 minutes, but you physically lose more ENERGY from the system, because you are maintining a higher temp diff, and thus higher flux of heat.....

there may be an upper limit of flow rate to allow transfer of heat from the fluid incontact with the walls and the centre of the channels, but i very much doubt it is reached in the stock system.. this would be identified by a HE exit temp being similar to the inlet temp.

and of course the opposite is true for the interwarmer... you want the lowest inlet temp to have the highest temp differential....

meh, anyway

Yerp that's the basic science - I guess while I've got my heat exchanger out of the car I could try and get some more quantifiable tests done on it when I have time... (don't hold your breath).