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MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

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MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby gomulletgo » Fri Jan 14, 2011 2:01 pm

Hi guys,

In this section I want to hear from people about the best ways to get the maximum power and torque from a 4JB1-T engine, don't worry this is not for my daily driver truck and I have heaps of spares :D

I've seen some very inspiring videos lately on youtube, plenty of american V8 diesels over a thousand horsepower. A mercedes station wagon drift car with a 3litre turbo that seems to have power to burn and apparently the engine has not even been opened! All external mods :D

Here is some inspiration:

http://www.youtube.com/watch?v=CpjPIj1YF0M
http://www.youtube.com/watch?v=EK3yblKCz0c
http://www.youtube.com/watch?v=LHPyjSG9p2M
http://www.youtube.com/watch?v=ZrsJ3upIr8Y

So what have you done that has worked? What do you know of mates doing that has worked? What is a good website for learning about modifying diesel turbos for heaps of power/torque?

What is the maximum power/torque you can put through a stock 4JB1-T before you develop problems? What problems arise first? How are these problems overcome?

Also can anyone tell me the stock weight of a 4JB1-T engine?

Thanks in advance :D oh and post any videos of powerful isuzu diesel turbos if you find them please :twisted:
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby turnturn » Fri Jan 14, 2011 5:52 pm

I think a 4jb1-t weighs about 250kg.
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby geeves » Fri Jan 14, 2011 6:24 pm

The most modified 4jb1 I know of was this one from the old forum
http://clubisuzu.proboards.com/index.cg ... 020&page=1
Aint much left to do to that one. He was drag racing it
Sanding your knuckles before starting work can help. That way you cant skin them
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby Captcol » Fri Jan 14, 2011 8:21 pm

thats insane, only read the first few pages but jebus ...
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby gomulletgo » Sat Jan 15, 2011 6:41 am

Thanks geeves, Just read the whole thing. It's a pity alot of the pictures aren't working. Does anyone know how it turned out? Dyno figures? Videos?
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby geeves » Sat Jan 15, 2011 5:19 pm

He never came to the new forum so cant help
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby bazza2541 » Sun Jan 16, 2011 1:18 pm

I found him on youtube. I sent him a mesage looking for more info. If he replies maybe I'll invite him on here?
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby geeves » Sun Jan 16, 2011 5:34 pm

link please?
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby gomulletgo » Fri Jan 21, 2011 3:54 pm

linked: ;) http://www.youtube.com/user/superturbocompound

Not much on the isuzu engine unfortunately.

On the subject of max power and torque from a 4JB1-T what is the max boost pressure people have run? A guy on here says he is running 20psi. Some people think running high boost doesn't actually give much benefit and can damage the engine easily, how does it damage the engine? Why does running high boost not give much benefit?

I have a friend with a 92 ish toyota hilux surf with the 2.4 turbo (2LT) it is on 35inch tyres, beam axle front, he is a diesel mechanic, he is running 25psi in his truck, it has a second hand head on it, which has been repaired "tubed" I think is the term he put on the manner of the repair. The wastegate does not open, so it's free boosting, I think he may have said it was welded up to even stop leakage. The thing goes like a cut cat!!! it blows my mind, it is way way faster than my stock standard truck on the road. It frankly scares me (tall truck going and cornering that fast)

I would be wrapped with that kind of performance out of my truck even on little tyres.

Is my diesel mechanic mate crazy? He hasn't blown the head, he's been running that boost for a long time and no way is he light on the throttle, he hammers it everywhere from what I've seen. Yes he has boost and EGT guages. He does not seem in the slightest concerned at the possibility of blowing his engine.
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby geeves » Fri Jan 21, 2011 5:14 pm

He does not seem in the slightest concerned at the possibility of blowing his engine.

Thats the real answer. He knows he can fix it or get another engine cheap. The 2lt does produce good power for its size but even a stock one driven gently will pop a head before 150000km and need a full recon by 200k. We have several documented isuzu engines untouched past 400k. Also he will have other mods to improve the chances of it staying alive. There is no way he could get 25lb boost with stock exhaust. It wouldnt flow well enough to prevent back pressure. I bet hes running a bigger than standard radiator.
If you want to build a war machine with no cost spared there is plenty you can do and 17 is achievable with the standard turbo and a 2.5 inch exhaust. Then you adjust fuel and fuel timing to suit and you will have about 100kw. Another CHCH member ran this setup in a swb Bighorn for 120000km plus whatever that engine had already done trouble free. He put the same mods on his LWB. A different turbo and blocking the overboost valve could see you up past 20lb and a few mods to the fuel pump should see another 20 or 30kw but you will find that low end torque has gone out the window not that there was a lot to start with. If you want to go this way do consult experts and spend lot of money. Unless you do something silly like pop a heater hose you forgot to replace your motor will still be more reliable than your friends.
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby bazza2541 » Sat Jan 22, 2011 3:10 am

My 4JB1 is going in to get the fuel pump optimised now shortly. The company doing the work (N.I. Turbos) claim I'll see 160bhp when it's done. That's back into 4JX1 territory. ;)
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby mudslinger » Sat Jan 22, 2011 4:26 pm

i was running 15psi up until i had to put a 2nd hand injector pump, now not only does she go so much better and start on all 4 she boosts at 18psi.
the turbo has been rebuilt, 2.5 inch exhaust, custom dump pipe with waste gate seperate, and a top mount intercooler.

i've never had a diesel be that quick she just gets up and goes, well she does until clutch starts to slip
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby bazza2541 » Wed Jan 26, 2011 4:11 am

I got a message back from SuperTurboCompound.

"superturbocompound
Re: 4jb1 well one of the first thing is the turbo down pipe needs to be larger,intercooler also,mainly the fueling needs to be tweeked.i'd give you a brief summry on the project but i am abit busy...by the way the engine has started and the response is like a petrol engine,really fast!
Sent to: bazza2541 "
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby superturbocompound » Thu Feb 03, 2011 7:34 pm

hello,every one,its been along time,lots has changed but finally i see the finishing line
http://www.youtube.com/watch?v=1C2kHAbXJ10
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby geeves » Sat Feb 19, 2011 6:40 am

Thats massive
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby superturbocompound » Mon Feb 21, 2011 12:59 pm

that's a lot of power....based on my research, you can't go wrong on a holset turbo,i looked up alot of vids on youtube and alot of the finns are using these turbo.
http://www.youtube.com/watch?v=uDK3K2TlAWs
just listen when the turbo kicks in....
http://www.youtube.com/watch?v=SRmyJ3Wr ... re=related
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby gomulletgo » Thu Apr 23, 2015 8:32 pm

UPDATE: I've done some reading on getting max power out of direct injection (DI) diesels and indirect injection (IDI) diesels. Here it is in a nutshell, feel free to correct any of the below.

4JB1-T = DI
4JG2-T = IDI

In general:

Indirect injection (IDI) diesels have weaker heads due to the pre-combustion chamber in the head, they also run higher compression to make cold starting easier as heat is lost to the head at the start of combustion. As IDI diesels run higher compression they perform better with smaller increases in boost, though the weaker head limits the amount of overall boost that can be applied.

Direct injection (DI) diesels have stronger heads due to there being no pre-combustion chamber in the head, they also run lower compression as there is no heat lost to the head at the start of combustion. As DI diesels run lower compression they don't perform as well with small increases in boost, the stronger head means higher overall boost can be applied.

Examples of Max Performance:
IDI: Euro Mercedes, BMW, Volvos e.g. BlackSmokeRacing. OM606 (4V per Cyl) engines etc. Performance achieved with less boost? Good turbo matching? The fact than many Euro diesels are 4V per Cyl?

DI: USA Fullsize 4x4 such as Cummins 4BT, 6BT etc. (2V per Cyl) Performance achieved with more boost. Compound turbos. Water/Meth/Nitrous injection.

Given the 4JG2-T engines poor reputation it may be better to make a performance build out of the 4JB1-T ? 4JB1-T with compound turbos?
Last edited by gomulletgo on Sun Sep 10, 2017 1:26 pm, edited 1 time in total.
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby geeves » Fri Apr 24, 2015 3:15 pm

there has been talk in another thread of a direct version of the 4jg2 ie the 4jg1 engine which is direct injection but never turbod from factory. It was more an industrial engine. More likely to find it in a fork lift than a truck but it might be a good base. Full rebuild to convert though
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby gomulletgo » Mon Apr 27, 2015 9:00 pm

Hi Geeves, I've been keeping an eye on that other thread. Although my interest lays more in a "stock" engine with the right "bolt ons" rather than an engine build/convert.

I'm thinking of using a 4JB1-T or 4JG2-T with upgrade "bolt ons" if the engine was to blow up it would simply mean bolting the goodies on to a replacement engine rather than an engine rebuild. Given this type of plan what does everyone think would be more suitable the 4JB1-T or 4JG2-T?
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Re: MAXIMUM POWER AND TORQUE FROM A 4JB1-T 2.8 LITRE ENGINE

Postby geeves » Tue Apr 28, 2015 3:31 pm

To be honest despite now owning 2 4jg2s I tried very hard for 19 years to blow up the 4jb1 and couldnt. It only had 220k on it though plus or minus any importers adjustment but it lived on the rev limiter.
The 4jg2s are good though but not for all out power. Try aiming a 4jb1 at a hill with the revs at 1000 and flooring it. 4jb1 complains bitterly 4jg2 just does it but at the same time its pretty much out of breath by 4k.
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