Outer Limits 4x4 Board

Hi guys,i have a patrol TD42 with a CT26 turbo and its supposedly running 10psi,as thats what the previous owner told me.I have a boost gauge but havent fitted it yet. I did a search and most of my questions were answered.i would like to run a little more boost.Do most fit boost controllers to do this or can it be done at the turbo.Were do you run a boost controller from if thats what you do?Im hoping to run about 15-16psi with a cooler,from what ive searched 14psi is possible but thats about it.Has anyone hi flowed or rebuilt there turbo to handle the higher boost?I have heard that you can rebuild the CT26 with garret internals and converting it to a BB turbo.How true this is im not to sure,maybe someone on here knows more.Im not really interested in changing the turbo with a garret as it means manifold change and so forth and would rather keep it simple.All your opinions will be much appreciated.Cheers Loz.

I think you can adjust the preload on the wastgate actuator spring.

i fitted a boost controller by extending the boost line from the turbo to a boost controler then back to the waste gate actuator.

its generally accepted that CT26 will handle 15psi safely, beyond that I guess you take your chances, I have run mine up to 22psi with no problem.

You can hi flow the CT26 and fit garrett cores and convert them to ball bearing centres, get some prices for this, hella expensive !!! the only advantage would be it will bolt up to an existing setup with out custom manifold and exhaust dump pipes etc.

For the cost, you would be better off getting a suitable BB garrett IMO

I have a boost controller on mine, and it is running 17 at the motor...(has larger front wheel) i would put a washer under each bolt that holds the gate and see what happens...probably 2 psi...14-15 should be your ceiling being std...but...what kind of ct26 is it twin entry to turbine housing has ceramic wheel and 14 max....all single entry have steel wheel and te sky is the limit....to check, twin entry has 5 bolt dump, single entry has 4 bolt dump.....

Hi guys, thanx for your info. Havnt got prices yet but i will start chasing some up. I would prefer to keep it a simple rebuild but i suppose it depends on how good the turbo will be after the rebuild. If im better of goin the garret path it will have to wait a little longer. Yeh sorry i should of mentioned it is a single entry turbo. Thanx again for your info. Cheers Loz.

Hi,

I run a CT26 in my 12HT. Not sure why you would want to muck around with adjusting the waste gate springs, when a needle valve boost controller does the trick. A little fiddly to get right, but it's an effective way of adjusting boost. I run mine at 12.5psi.

Tim

there is about 11ty billion variants of the ct26, about half having ceramic front wheels which like to blow into 500 piece above 15psi, the others having a steel front wheel, being from 7m motors various group a 3sgte's and 1hz's and having single entries, so as has been said your in luck.

Imo i wouldn't bother rebuilding any toyota turbo just to save on a manifold/dump pipe when they will be replaced for a superior item to gain low down boost/flow, adaptor plates can be made/bought to bolt more efficient/larger units to the manifold, new dump pipes and water/oil lines would need to be fitted, a bb (ball bearing) unit matched to the motor would come on at a earlier/similar time to the ct26 with the extra of being able to hold the boost longer in the rpm. Ball bearing turbo's spool easier due to the reduced restriction from the bearings, enabling them to spool bigger wheels earlier, which is when the bigger wheels are able to produce the boost as the rpms rise needing more air flow.(does'nt make alot of sense if your unfamiliar with the workings of turbos)

Installing any ball and spring type boost controller will aid in low down power/torque, as it holds the gate 100% shut until the desired boost is reached, normal gates open a little due to the boost rise until the boost is reached then they slam shut, electronic boost controllers work even better but are big coin for the small gains youll see from diesels, offering a scramble function etc, which overboosts the turbo to a set psi for a set amount of seconds to get it off the line etc and pulls it back to the set psi.

Tim HJ61 wrote:Hi,

I run a CT26 in my 12HT. Not sure why you would want to muck around with adjusting the waste gate springs, when a needle valve boost controller does the trick. A little fiddly to get right, but it's an effective way of adjusting boost. I run mine at 12.5psi.

Tim

the reason why is if you turn up boost significantly with a controller, the waistegate creeps open above the std boost setting, which is set by the spring tension in the actuator...ie with mine, std boost was 12.5, and i run 17...above 12.5, boost to actuator is being bled off, creep in spring is not happening from boost applied to diaphram, but the extra exhaust pressure is overpowering the std 12.5 spring pressure via the butterfly in the turbine housing you still boost to your 17 adjustment, but it comes in later than if you pack the spring...packing the spring allows less creep down low...and earlier full boost. I hear you thou...thats why i did the controller to mine...too fidly getting into do the packing...only to have to do it again because you didnt do enough
Andrew

I fitted a boost controller to mine and it tops out at 13psi.I have read that the ct26 is not efficient and makes too much heat above 14psi.Should I be changing compressor wheels if I want to go higher?

Would it be possible/feasible to do this..........

put a 12 volt solenoid valve between the actuator and turbo. run an adjustable boost/pressure switch between turbo and inlet manifold. Set the pressure switch up to the desired boost you want, so that when you reach it, it activates and sends 12volts to the solenoid in the actuator line, opening it and letting the boost pressure close the wastegate.

Anyone tried this?

flyology wrote:Would it be possible/feasible to do this..........

put a 12 volt solenoid valve between the actuator and turbo. run an adjustable boost/pressure switch between turbo and inlet manifold. Set the pressure switch up to the desired boost you want, so that when you reach it, it activates and sends 12volts to the solenoid in the actuator line, opening it and letting the boost pressure close the wastegate.

Anyone tried this?

No I haven't and wonder why you would when a boost controller costs $30,takes about 10 minutes to fit and is easily adjustable.

I was under the impression that even with needle valve style boost controllers there was still the issue of actuator creep. No boost at the actuator, no creep, faster spool up?

flyology wrote:Would it be possible/feasible to do this..........

put a 12 volt solenoid valve between the actuator and turbo. run an adjustable boost/pressure switch between turbo and inlet manifold. Set the pressure switch up to the desired boost you want, so that when you reach it, it activates and sends 12volts to the solenoid in the actuator line, opening it and letting the boost pressure close the wastegate.

Anyone tried this?

this is how some controllers work..dual stage for instance has 2 adjustments and one is closed with a solenoid when switched for high boost.......they also do other things like pulse on and off faster as the pressure comes closer to setpoint even close when changing gears so the turbine keeps speed and the dump is open...