• Advertisement

4jg2 most HP

Getting the best performance from your Isuzu, the in's and out's

4jg2 most HP

Postby rustyvr4 » Fri Jan 04, 2019 5:53 am

just a curious question for those who have or had the 4jg2t engine. what is the most horse power you can get out of them?, and maintain good reliability. what are the steps taken to get the horse power you got or are getting?
No officer i wasn,t slideways i think you was seeing things sir
rustyvr4
Isuzu Baby
 
Posts: 30
Joined: Sun Apr 24, 2011 9:41 am
Age: 33
Country: new zealand
City: tauranga
Vehicle: 1996 mu 3.1 turbo MANUAL, running 20psi. fuel maxed out. air adjustable shocks in rear. gas struts on bonnet

Re: 4jg2 most HP

Postby tonkamu » Fri Jan 04, 2019 8:14 pm

You can get a lot out of any engine if you spend big money. Do you mean decent gain in hp while keeping it reliable? Is it an efi or mechanical pump. Just the usual mods is about all you can do, unless you go bigger turbo and more fuel. But I don't think 4jg2 heads last long with a lot of boost? Even what you're running 20psi is more than what's considered "safe" on 4jg2 from what I've read, safe max is 15?.
tonkamu
Isuzu Senior
 
Posts: 156
Joined: Sun Jan 01, 2017 7:23 am
Age: 36
Country: NZ
City: Auckland
Vehicle: 2.8 Mu 1991 All Black. MODS - Rear Lifted 2.5" Lovells Leafs / Rear Auto Locker / LSD in front / 33x12.5x15 MT Achilles / 9500 RUNVA w plug n kills switch inside cab / EGT, Voltage, Turbo timer, Boost gauge / 20 PSI VF10 Turbo with VF10 exhaust housing 2.5" downpipe with merged 2" wastegate pipe to full 2.5" straight pipe / GFB Boost Tap / Maxed fuel with grinded down cable stop / Adjusted Boost Compensator / 3.1 Oil Cooler / Intercooled / 3" Custom intake to sealed K&N airbox & filter to Snorkel / Catch Can / Xtreme Outback HD clutch / 80 amp alt / RockfordFosgate 300rms AMP w 2X Rockford Power 6x9's BT HDeck / all EGR, QWS, AC pump deleted.

Re: 4jg2 most HP

Postby geeves » Sat Jan 05, 2019 6:12 am

Best way to go with 4jg2 is 4jg1 pistons 4jj1 or 4jg1 head and diesel pump 12mm plunger in pump and tune away. You are looking at a full recon to do this and it would only give a little more power than you can get out of a 4jj1 which would be cheaper to get by buying a low mileage holden ute and stripping
Sanding your knuckles before starting work can help. That way you cant skin them
User avatar
geeves
Site Admin
 
Posts: 8391
Joined: Sun May 10, 2009 1:36 pm
Location: wellington
Age: 55
Country: NZ
City: Wellington
Vehicle: 94 bighorn 4jg2
2004 Honda CRV

Re: 4jg2 most HP

Postby rustyvr4 » Sat Jan 05, 2019 7:28 am

model i have is mechanical pump. so far on the pump i.v adjusted the boost comp, rotated the cone shaped thing and backed off tension on spring. adjusted fuel rate screw. and backed of, cold start device adjust screw. been running peak 20psi nearly a year. 100kmh on open road she pulls 8psi. yet to do intercooler and proper exhaust. can i go to big on intercooler? thinking about using this as a top mount https://www.trademe.co.nz/motors/car-pa ... 476944.htm
No officer i wasn,t slideways i think you was seeing things sir
rustyvr4
Isuzu Baby
 
Posts: 30
Joined: Sun Apr 24, 2011 9:41 am
Age: 33
Country: new zealand
City: tauranga
Vehicle: 1996 mu 3.1 turbo MANUAL, running 20psi. fuel maxed out. air adjustable shocks in rear. gas struts on bonnet

Re: 4jg2 most HP

Postby geeves » Sat Jan 05, 2019 2:16 pm

That intercooler is designed as a front mount for a smaller engine. Front mount is always going to work better but there are plumbing challenges. Factory intercooler with an added fan will do as well
Sanding your knuckles before starting work can help. That way you cant skin them
User avatar
geeves
Site Admin
 
Posts: 8391
Joined: Sun May 10, 2009 1:36 pm
Location: wellington
Age: 55
Country: NZ
City: Wellington
Vehicle: 94 bighorn 4jg2
2004 Honda CRV

Re: 4jg2 most HP

Postby handymanny01 » Sat Aug 24, 2019 10:09 pm

Thought I'd share my experience in this area... my 4jg2 had been running 20 psi, VF10 hybrid , and a maxed out std injection pump,, for years,,, with water to air intercooler,, and 3" dump and full 3" system, 3" inlet and pod filter... (and all normal mods like egr delete) dynoed recently at 95kw / 127hp at the wheels,,,, Then fitted a REAL hot rod injection pump,,, Holy shizz!!! Estimated 125kw at wheels (145kw ish at crank) Sadly only lasted 2 weeks,,, serious piston damage,,, (as it flew past 160kph on 33's) So I'd say safe limit on 4jg2 is prob 100 kw at the wheels... and 600 c on the EGT ,,, 650 c for brief periods,,, Next build is 4JG1-T (will post all details , and dyno result) stay tuned!
handymanny01
Isuzu Baby
 
Posts: 9
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Vf10 hybrid, ported wastegate, mild port head, custom pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg2 most HP

Postby AusZuMu » Sun Aug 25, 2019 8:07 pm

Looking forward to the updates Handymanny01, I have a long list of maintenance and servicing tasks I should do before I get into the performance mods for my 4jg2.
Picking lines and stripping splines.
AusZuMu
Isuzu Baby
 
Posts: 8
Joined: Sat May 18, 2019 9:58 pm
Age: 27
Country: Australia
City: Canberra
Vehicle: 1995 ISUZU MU 3 door SWB 4GJ2T

Re: 4jg2 most HP

Postby handymanny01 » Sun Sep 08, 2019 6:17 pm

Gotta say,,, these are TOUGH little engines!! (4jg2) Pulled her to bits over the week,,,, over 300'000 kms,,, and the crank is still within service limits! And the recent blow up, damaged 1 piston and liner,, and that's it! 4jb1 head purchased, and slowly sorting which 4jg1t pistons are the most suitable,,,, then the 4jg1t rebuild will begin!! Liner removal pics to come...
handymanny01
Isuzu Baby
 
Posts: 9
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Vf10 hybrid, ported wastegate, mild port head, custom pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg2 most HP

Postby handymanny01 » Wed Sep 11, 2019 5:23 pm

The damaged piston.... prob the result of squeezing an estimated 140kw (crank) out of it... lol
You do not have the required permissions to view the files attached to this post.
handymanny01
Isuzu Baby
 
Posts: 9
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Vf10 hybrid, ported wastegate, mild port head, custom pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg2 most HP

Postby handymanny01 » Wed Sep 11, 2019 7:54 pm

Pressing the liners out of the block,, needed to make a special tool.., bout 5 ton to press them out... block seems totally fine.... will prob get it decked very lightly though.... just so it's perfectly flat,,,
You do not have the required permissions to view the files attached to this post.
Last edited by handymanny01 on Thu Sep 12, 2019 4:00 pm, edited 1 time in total.
handymanny01
Isuzu Baby
 
Posts: 9
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Vf10 hybrid, ported wastegate, mild port head, custom pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg2 most HP

Postby handymanny01 » Wed Sep 11, 2019 7:58 pm

The new 4jb1t head mocked up on on the 4jg2t block,,,, ohh yes! It will be so!!
You do not have the required permissions to view the files attached to this post.
handymanny01
Isuzu Baby
 
Posts: 9
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Vf10 hybrid, ported wastegate, mild port head, custom pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"


Return to Engines and Exhaust

Who is online

Users browsing this forum: No registered users and 2 guests