Turbo Upgrade...

[Stu]

Anyone played with changing the turbo on a 3.1 Irmsher Bighorn for something decent? The spare truck has a really weird whine so I'm thinking about swapping Dads turbo onto it and then upgrading his to a VF10 or something similar. Anyone got any recomendations?

[MattMU]

Nah havenbt done it Stu but emaila few people about it and they were all keen to have a crack...at my expense. They were confident they should be able to fit something up that would be more modern, is variable vane or something similar!

Love to know if you have a crack, Im still running a 2.8 turbo on an intercooled 3.1!! I seriously have to get off I disagree and get that sorted!

Matt.

[Stu]

Haha, cheers for the reply Matt. The obvious upgrade would be a VF10 or similar that has the same bolt patterns and runs a larger compressor and shaft.... BUT I'm trying to convince Dad to go for something larger yet and more reliable. Unfortunatly its a hard road convicing the old bugger once his mind is made up. I'm in the process of rebuilding a VF10 for him so will post up with how it goes once its on. Just really interested to see what anyone else has done.

[Stu]

Finished rebuilding the turbo, just have to mill the existing turbo housing ever so slightly to allow the bigger rear wheel to fit then bolt the turbo together. Also have to make a new front adapter for the intake pipe to connect to but that shouldn't take long. I'll take some pics if I remember. Should be all going in a couple of weeks.

[Jimmu]

Hey Stu,

How is the upgrade going?

Jimmy.

[Stu]

Actually it got put on the back burner as I'm having trouble sourcing a spare turbo housing I can have a play with without having to pull the truck to bits. I had one that I thought was right but turns out the A/R is smaller so wont do. Everything is ready bar the housing haha

[geeves]

Is fitting a biger turbo a good idea. These turbos already produce max boost all the way to the red line so the only likly differance is a reduction in boost at low revs. A few people have replaced 3.1 turbos with the ones from 2.8s and found much better low down torque and hardly any loss at top end

[Stu]

Yes I believe changing the turbo is a good idea and by getting the right setup there will be no reduction in power lower in the rev range. Our aim isn't to run more boost and stress the turbo for little gain, but rather run the same or lower boost and achieve better CFM. The exhaust wheel will be very similar in size to the existing unit so spool characteristics will be almost identicle and by using a larger shaft the turbo will better handle long periods of heavy loading. We are also interesting in trying a few different combinations out and just seeing what happens. Very little is know regarding changing the turbos appart from the 2.8 swap as you suggested, so without trying things how will we ever know? There may be an easy upgrade around the produces that extra bit of torque that everyone is after

[andy]

Recently i heard that it is quite common for people to run bighorn exhaust housings/turbines with subaru compessor housings/compressors on small turbocharged petrol engines.
If this is a relatively common place upgrade i might try it if my turbo ever lets go. A little extra flow at less or similar boost has to be good for power.

[powertruck]

hey guys im new to this site im from CHRISTCHURCH New Zealand work for a turbo company, i own a 93 isuzu mu with a few mods, I am running the rhb5 turbo with the vf8 comp wheel, im not running the standard exhaust housing running a 20r housing as oposed to the 15r, made no diff to the lag but gave it alot more midrange

[powertruck]

i'll get sum pics posted of my setup, im running the bighorn intercooler just had to modify the outlet pipe to suit, im running a bonnet scoop which seems to be working fine, cant stress how much of a difference the vf8 wheel made, ive lowered my boost from 10psi with the original turbo to 7psi and making more power than it originally did also by altering the exhaust housing it has allowed it to breathe alot better, i personally think that for a 3.1l engine the standard exhaust housings are way to small/restrictive with a 20r housing and a 2.5" exhaust you will notice a massive improvment

[geeves]

Heres an interesting question for the experts. Im running 2.5 from the end of the front pipe to the back but still have 2 inch for this section which Ive managed to bend so its now knocking on the floor and will have to be replaced now. Exhaust shop tells me that to go 2.5 inch all the way to the turbo risks overheating the turbo. I know that 2.4 Surfs benifit greatly from 2.5 inch pipe all the way which is the oposite to what the exhaust shop is telling me. Shouls I go 2.5 inch all the way or keep the front section in 2 inch. Performance is more imortant now than long term reliability but I dont want to deliberatly do anything bad to the car.
First comment from the exhaust shop when giving me a quote was "you are going to waterblast it first arnt you"

[mulover]

That exhaust shop is talking crap because its a prick to do, ive got 3" all the way, threw out the casting (2.8 motor) that comes off the turbo and never looked back, never had any problems, a guy i know had a 3" all the way on his 3.1 and that thing used to hall serious but, good for 160km on 32" tires Check out my 3" for a 2.8 thread for some pics of what ive done.

John.

[powertruck]

Its all good to run a 2.5" system but when the turbocharger is in standard form they rely on sum backpressure for the wastegate to operate properly, by opening up the exhaust system you allow the gases to escape and expand faster allowing the turbine to do more work, this causes the turbo to over speed which can lead to thrust bearing failure which is very common. As for the toyota 2.4 engine the turbos on them are far to small to start with so the big exhaust helps get rid of sum heat they create. I have a 2.5" system on my 3.1mu but im running a different turbo ive had the turbo off and checked it for wear and it was fine. hope this info helps

[geeves]

How much 2 inch pipe do yoy recomend I keep?? If I keep from the flexi joint forwards as 2 inch it costs less than half a complete job.I belive my turbo is original at 16 years and 180000k

[mulover]

As little as possible, I have absolutly no regrets about the 3" the turbo is still in good nick, amasing power and torque down low and sounds good, and so what if the turbo blows, i'll just put a bigger one on, with a better exhaust manifold leading into it!!!! and if that doesn't work then its chev mate hehe!!!!

[geeves]

Ok Ill probably get it cut at the flex joint New flex joint was going to be 140 to buy so this way I save a little . As it is I have 13.5 boost from 2200 through to the rev limiter at 4200

[dani4JB1T]

A friend of mine is selling me a brand new sealed in box turbo Garret T25 in US$230 (yes...230 US dollars, he doesn`t know what he has in his hand).
I don`t know anything about Garrets, but maybe could be a good upgrade to my engine due to its cheap price and new condition. Im going to see it during the week at his home to check the flanges, read the specs at the box, etc...however i believe it is for small petrol engines.

What do you think guys ??

[geeves]

our 2.8 engines running flat out at 4200 are only useing the same air as a 1500 at 8000 or a 2000 at 6000 so if it handles that it should be ok for our engines. The std turbo on our wagons is also std on early legacy and wrx rally cars