Outer Limits 4x4 Board

Hi guys, just wondering if I could get your opinion on this topic.
I have just put a CT 20 turbo on my 5L hilux, I got it dyno tuned and they said the turbo was boosting too late, around 3000rpm instead of 2000rpm. and I am getting too much psi out of it. I have also noticed oil leaking too, But I have put that down to not running the oil return drain straight into the sump but instead I tee'd into the alternator return line. so the oil is backing up. The question is should I buy a brand new CT20 turbo or do you think the turbo may not be the problem? appreciate any advice, thanks.

I can't explain why it would be boosting late - my ct20 on a 2.8 boosts from 2000 up to 3000 maxing around 11psi.
When I researched before installing mine I found that there are a few different models of ct20 mine is the older non water cooled model with a smaller exhaust inlet that apparently gets on boost at lower revs.
I also found plenty of people that reported oil leaks when taping the return into the alternator as you have alread mentioned (and people that had no issue). I connected mine into the sump.
Is the oil leaking into the exhaust (white smoke) or into the high pressure inlet side (past the compressor)? Mine leaked into the inlet so I rebuilt it (new seals - changed from a carbon to a dynamic seal) and it still leaks a litle but no where near as much as before. Overall based on my experience and reviews I've read about the chinese ct20 copies I'd probably get a chinese ct20 (around $400) rather than spend $200 odd (kit and balance) on a rebuild that is only going to renew seals in a really old Turbo (mine is off an early 80's 2.4).

This is the link to the guy who reviewed the chinese ct20
http://www.toyotadiesel.com/forums/show ... 827&page=8

The oil was leaking out the exhaust and out the intake side I think. Is it easy to drill into the sump? I'm not sure what the problem is with my turbo but I do think I need a new one. Did you get a dyno reading? If so how much power did you get? On the dyno reading it said at my max power output it was up to 16psi and I dont think thats too good for my car lol. Have you had any overheating issues or any other problems with installing the turbo? thanks

What were your EGTs like? 16psi is nice, but EGTs is what kills the motor.


CT20 should have the oil return to the sump or you will have problems.

I haven't had a dyno tune but I do notice much more power especially on the highway overtaking or holding 100 on a slight hill (which were real problems before the turbo).
For reference my EGT's (taken before the Turbo) average between 200 - 350 C with the top reading I've seen a shade over 500 C pulling up a hill.
No issues with overheating but I do use more fuel (currently get around 350ks to a tank) - might back the fuel adjustment I made off a little.
I couldn't find anyone to braze my brass fitting into my sump (stopped looking after there didn't seemed to be much intrest) apparently welding a steel fitting would have been easier but I already had the brass one and was eager to get the Turbo in. I ended up using a method I found on his forum - plateing the sump with a piece of aluminium and threading the fitting into that and the sump with sealant to help out. One thing I found when putting it back was that jacking the car up a bit made it much easier to get the sump to clear the diff without scraping the sealant off.

ae86levin wrote:I haven't had a dyno tune but I do notice much more power especially on the highway overtaking or holding 100 on a slight hill (which were real problems before the turbo).
For reference my EGT's (taken before the Turbo) average between 200 - 350 C with the top reading I've seen a shade over 500 C pulling up a hill.

wow if they are you before turbo EGTs and its definitely in C then I would be winding up the fuel!!! I have mine tuned to 700c pre turbo. By winding up the fuel I got better economy, as long as I am not thrashing it anyway.

I didnt get my EGTs checked, my temp guage doesnt go over half still. But I will c how it all goes when I get another turbo and run it into the sump. Hopefully that fixes everything up.

Definetly pre turbo degees C. I'll give it a bit more fuel in that case.

A leaking wastegate flap will delay boost.

500C post turbo is about as hot as you want to go. Shift the probe to the manifold if you want to know what's really happening.

there is several versions of CT20 including petrol models, so make sure you have the right one.
they are not a great turbo at the best of times.
trouble with putting them on a 5L is the turbo is on the small side. you now have a bigger motor plus pushing nearly double boost pressure. thats a big increase in flow and they are horrible at such high flows. intake air temps skyrocket which hurts your EGT's.
i would drop the boost right down.

the low boost could be wastegate stuck open a little bit or simply under fuelling.

the ct20 gets a lot of hard calls against it but i found it fantastic value for money.

the ct20 should boost up fast on a 5l as the are designed for a smaller engine. some say they are too small for the 5l but i think it depends on what your after.

for a good increase in power at say 11psi max then they will do just fine.

Sounds like your wastgate might be the issue, some have had heat damage and dont move properly or seal anymore.

mine had the diaphram in it go and it wouldnt make boost properly, try holding the diaphram shut manually and seeing if it boosts faster?

If you pull your inlet to turbo line off, do the vanes spin easily? if not they should and this would limit early spool.

how do the exhaust and inlet vanes look? if these are shitty they will delay boost.

thast combined with a dicky wastegate is the only reason i can really think of to do what your describing.

p.s get and egt and good boost gauge. auber ins.com for the egts are cheap btw.

when it comes to oil coming out of the turbo i have had this problem i tead it into the altanator spat oil evry where i drilld into the sump put strait flow prob fixed and with boost issue get a some wasshers ant put them behind the two 12mm bolts that regulates the waset gate and u will be fine i got a kit off ebay and rebuilt my turbo easy azz

Yeah I thought the wastegate may be the issue, Im picking up another surf turbo tomorrow, so I will have a look at it when I pull it out. The vanes on the turbo were fine, spun easy. Whats the easiest way to tap an oil return into the sump? Is it hard to drop the sump on a 5L hilux? does the diff get in the way? Also does anyone else recommend any other places to get EGT guage and boost guage? Are they easy to install?

I think I may have solved the leaking oil problem, I didnt relocate the rocker cover breather, so pressurised air was going into the rocker cover, so I hooked it into the low pressure side of the turbo. Hopefully that fixes the oil issue, Also I think I noticed a leak out of the manifold, so that might be why the turbo wasnt boosting till 3000rpm. Any suggestions on how to find if there is a leak? or do I just have to take the whole thing off and re do all the seals?

EGT pyrometer source - Auberins in the US is where I got mine. Rember you need to buy the thermocouple separate. Was easy to install - I tapped my thermocouple into a blanking plate I made to block the exhaust gas recirculate hole at the end of the manifold.

http://www.auberins.com/index.php?main_ ... c65ff160e1

hulsty wrote:

ae86levin wrote:I haven't had a dyno tune but I do notice much more power especially on the highway overtaking or holding 100 on a slight hill (which were real problems before the turbo).
For reference my EGT's (taken before the Turbo) average between 200 - 350 C with the top reading I've seen a shade over 500 C pulling up a hill.

wow if they are you before turbo EGTs and its definitely in C then I would be winding up the fuel!!! I have mine tuned to 700c pre turbo. By winding up the fuel I got better economy, as long as I am not thrashing it anyway.

I have wound an extra 1/4 turn on my fuel screw and it made a huge difference - revs more freely and comes on boost way quicker. Feels like much more power.