isuzu 4BD1T swap?!

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

A few questions on the aw450... I know the starter is rear facing on it, but is the block/bellhousing bolt pattern the same as the 4bd1/2T's??? I gather a bolt or two might not be in the right place due to the starter, but the rest? Giving up a bolt or two is not too much of a concern to me, if the other 8 or so work out.

I found a actual picture diagram of the aw450 internals. I dont have either a a440 or an aw450, but maybe someone can compare to the output on an a440...

website:http://www.ganzeboom.net/images1/ganzeboom/parts/Aisin Warner/AW450-43LE.pdf

does anyone know the gear ratios of the aw450? mostly concerned with OD ratio. Anyone with the Isuzu FSM have these availible?

The AW450 that came with the 4HE1 and 4HK1 engines will not bolt up to the 4BD1/2. I did try to mate up the AW450 bell housing to the back of a 4BD1 unsuccessfully as the back end of the blocks are different.

If you want more details on the AW450, you can download the FSM from here: Master Portal - forums.bauchan.org/Isuzu Manuals The AW450 is covered in the chassis manual, 1999 and later. Unfortunately, I couldn't find the gear ratios in the manual.
 
guys i need a favor, i dont have access to an isuzu 5 speed right now (go figure) can someone get me right-on measurements for the input shaft length (from the bellhousing mount surface) and the diameter of the shaft at the pilot bearing.

this is for a 4BD1T engine.

thanks in advance
 
guys i need a favor, i dont have access to an isuzu 5 speed right now (go figure) can someone get me right-on measurements for the input shaft length (from the bellhousing mount surface) and the diameter of the shaft at the pilot bearing.

this is for a 4BD1T engine.

thanks in advance

Shaft diameter 17mm.
Shaft protrusion 81mm +/-1mm.
 
81mm,,,,, just to be clear i'm looking for the overall shaft length from the face of the transmission case. that number is the stickout as you lay a straightedge on the bellhousing?

thanks dougal i figured you would be on top of it, if you can get an overall length i'd be i your debt as i dont have a tranny or bellhousing for my own measure.

i'm working with a machinist to mill a new bellhousing that will mate an H55F tranny to the engine, if it works out we'll then have a go at the easy part, re drilling the isuzu flywheel for a cruiser pressure plate.
 
I'm using a smaller turbo than stock, mine is a wastegated T25 with a 0.49 A/R exhaust housing. The stock turbo is a TB25 which has exactly the same compressor but a bigger exhaust housing and no wastegate.

I have been running those temps for the last 8000km and see no damage. I've had the occasional excursion past too. Most people put excessive safety factors on their EGT levels.



Hey that's new, I have never seen that turbo before. The 4BD2's I've seen had no wastegate. Yes it's the same flange and core.
You'll be able to push close to 20psi with the stock turbo, but only at higher rpm. Probably suffering smoke and high EGT's below that or poor response if you have the boost compensator set to deal with the smoke and EGT's. This is why I went smaller, I have 20psi boost from ludicrously low revs.

Yes an intercooler is a good idea, I haven't yet fitted one. Partly due to space, mostly due to sloth.

curious what this 4bd2t turbo core is and how it compares to the t25? sounds like dougal you have a t25 but with a smaller hot side housing?

i am interested in more turbo boost, and the garretts would be much easier to configure into the current engine setup.
 
curious what this 4bd2t turbo core is and how it compares to the t25? sounds like dougal you have a t25 but with a smaller hot side housing?

i am interested in more turbo boost, and the garretts would be much easier to configure into the current engine setup.

The non-wastegated turbo core is a TB25. Exactly the same bearing core and compressor as the T25 I'm running, but it has a larger exhaust wheel and bigger A/R exxhaust housing. It also has a T3 inlet flange.
I have one, but I haven't run it and it's unlikely I ever will.
The TB25 I have would need rebuilt and me to change all the pipes (exhaust, air intake, turbo outlet, oil in, oil drain), so it's not really worth the hassle.
 
more turbo options

still trying to wrangle up a turbo that works well on the 4bd1t. in looking at more, I end up with a ton more questions. any help is appreciated to understand the nomenclature of what seems to be the most important, and most complicated component of performance!

T3 - does this only refer to the exhaust mount?
T25 - this refers to the core size?
TB2522 - this turbo specifically as an example, how does this compare to the stock 4bd2t, or the nissan bluebird t25?

A/R numbers - this area to radius ratio, is it just comparitive, or does it relate to Mass air flow, or MAP?

from ebay...
This is a genuine Garrett T25 turbo. It is brand new. It's Garrett P/N 465749-5001. The Turbine A/R is .49. Compressor A/R is .48 This was the OE turbo used on Pontiacs in the late '80's. It has the same specs as the stock CA18DET turbo other than it uses different oil and water connections. It is good for about 225 HP.
garrett.t25.turbo.webp
 
still trying to wrangle up a turbo that works well on the 4bd1t. in looking at more, I end up with a ton more questions. any help is appreciated to understand the nomenclature of what seems to be the most important, and most complicated component of performance!

T3 - does this only refer to the exhaust mount?
T25 - this refers to the core size?
TB2522 - this turbo specifically as an example, how does this compare to the stock 4bd2t, or the nissan bluebird t25?

A/R numbers - this area to radius ratio, is it just comparitive, or does it relate to Mass air flow, or MAP?

from ebay...
This is a genuine Garrett T25 turbo. It is brand new. It's Garrett P/N 465749-5001. The Turbine A/R is .49. Compressor A/R is .48 This was the OE turbo used on Pontiacs in the late '80's. It has the same specs as the stock CA18DET turbo other than it uses different oil and water connections. It is good for about 225 HP.

So many questions.:)

T3 is a family of turbos, but T3 also describes a mounting flange. The TB25 that is stock on these has the T3 mounting flange. The T3 mounting flange is also used by a whole slew of other turbos from Holset, Schwitzer/KKK and a lot of custom ricer turbos.

T25 is again a family which is part of the larger T2 family. Yes it basically describes the core size but many parts interchange with other turbos from the T2 family including the larger T28's.

According to Turbomaster, the stock 4BD2T turbo is a TB2568
TurboMaster - Turbos - Despieces Modelo TB2568 - 466409-0002
The closest listing they have to my nissan T25 is this TB2525
TurboMaster - Turbos - Despieces Modelo TB2525 - 465795-0003
My part number is actually 455767-0003

Did I mention that I have designs for adapters to fit T25/T28 turbos to the T3 manifold you have? PM me your email and I can send you a copy.

That ebay turbo is functionally identical to mine. There are small differences (like different wastegate actuator), but they relate to the turbo packaging rather than function.
TurboMaster - Search catalogs and applications for parts and model numbers
 
turbo for isuzu

thanks dougal, owe you a beer!:beer: that will have to do until my next trip to NZ.

good information. i have found a lot of various garretts out there, so it is now really just making sure i know what i am getting.

mount - t3 mount is the isuzu manifold, and the stock turbo tb25 has a T3. but the t25 does not have a t3 mount? I have found some other t25 that is a T3 mount, so this should bolt on? i have your drawing, it is awesome, and will use if I need it, but kind of confused. what mount does your t25 have (if it has a different standard)?


turbo - have found some t25 off of 300zx, and some others. a/r of .49, and .60 as I recall for turbine, and compressor. part numbers are a nissan part number 14411 something.... getting more beta.

seems like this is slightly better than the wastegated 4bd2t, as the A/R of .49 is smaller, faster, than the 4bd2 A/R .67.
 
thanks dougal, owe you a beer!:beer: that will have to do until my next trip to NZ.

good information. i have found a lot of various garretts out there, so it is now really just making sure i know what i am getting.

mount - t3 mount is the isuzu manifold, and the stock turbo tb25 has a T3. but the t25 does not have a t3 mount? I have found some other t25 that is a T3 mount, so this should bolt on? i have your drawing, it is awesome, and will use if I need it, but kind of confused. what mount does your t25 have (if it has a different standard)?


turbo - have found some t25 off of 300zx, and some others. a/r of .49, and .60 as I recall for turbine, and compressor. part numbers are a nissan part number 14411 something.... getting more beta.

seems like this is slightly better than the wastegated 4bd2t, as the A/R of .49 is smaller, faster, than the 4bd2 A/R .67.

You're getting there.
My T25 uses the T2 flange. The T25 and T28 flanges use the T2 bolt pattern but sometimes the port size changes a bit.

The other turbos.
The 300ZX (twin turbo) used two T2/T25 hybrid turbos. They're smaller still than the T25 I have as each one is only feeing 1500cc of engine.
Nissan also have a T25G which is a supersized T25. It has "Nissan" instead of Garrett cast into the compressor cover but isn't suitable for high boost.

The nissan Skyline (don't think you'll find many of these in Canada or the US) has a small T28 with a 0.64 A/R exhaust and a 0.42 A/R compressor. I have one of these but haven't fitted it and probably won't. This is the next step above the T25.
The nissan Pulsars with the SR20DET engine have a T28 with a 0.84 A/R exhaust and 0.8 A/R compressor. This is getting near the disco potato turbo and is very large for our engines. I know a guy in Aussie who is currently half way through installing one so we'll see how it goes.
I also have one of these turbos (I'm a collector:D) which may be the big turbo in the compound setup I'm working on.
 
hey 88TLC, why not just run the HY35W9 that a bunch of the 4BT guys are raving about? You can pick them up cheap off craigslist or the classifieds section of TDR. Another option, only because I can speak of personal experience, might be an H1C. These turbos came stock on early Dodge Cummins 6BT and the Cummins 4BT. I drove a 4BT powered 80 series with H1C and aftermarket smaller housing (12CM is most common, usually no wastegate); it had great boost from just off idle, peaking at 22PSI.

the reason I am suggesting these, is they can be had cheap, parts are cheap, and they are plentiful.
 
hey 88TLC, why not just run the HY35W9 that a bunch of the 4BT guys are raving about? You can pick them up cheap off craigslist or the classifieds section of TDR. Another option, only because I can speak of personal experience, might be an H1C. These turbos came stock on early Dodge Cummins 6BT and the Cummins 4BT. I drove a 4BT powered 80 series with H1C and aftermarket smaller housing (12CM is most common, usually no wastegate); it had great boost from just off idle, peaking at 22PSI.

the reason I am suggesting these, is they can be had cheap, parts are cheap, and they are plentiful.

Those Holsets are huge. A good option if you've got the space but I haven't. There's a guy on 4BTswaps running one on a 4BD1T, but it's a recent build and he hasn't got the guages in yet.
 
isuzu 4bd1t with holset turbo?

hey 88TLC, why not just run the HY35W9 that a bunch of the 4BT guys are raving about? You can pick them up cheap off craigslist or the classifieds section of TDR. Another option, only because I can speak of personal experience, might be an H1C. These turbos came stock on early Dodge Cummins 6BT and the Cummins 4BT. I drove a 4BT powered 80 series with H1C and aftermarket smaller housing (12CM is most common, usually no wastegate); it had great boost from just off idle, peaking at 22PSI.

the reason I am suggesting these, is they can be had cheap, parts are cheap, and they are plentiful.

I looked at the one i found on 4btswaps.com, carcrafter 22. while it sounds like it works well, there were some significant adjustments made to make it work.

vac pump removed from alternator.

exhaust moves to aft.

intake moves to forward

exhaust port, is it a T3 ? it may be , but I am not certain.

these turbos are larger.
 
best garrett turbo for the isuzu 4bd1t

talking to this guy in montreal, at blaastperformance.com.
he is recommending the t3 50 trim

turbine .48a/r, 68 trim.
compressor .42 a/r, 42.5/60.1 50 trim


internal wastegated.



stage 1 1/2 turbine is also proposed, to get early spool up.

thoughts of this style? this guy can build up a unit with smaller turbine housing if needed.
 
talking to this guy in montreal, at blaastperformance.com.
he is recommending the t3 50 trim

turbine .48a/r, 68 trim.
compressor .42 a/r, 42.5/60.1 50 trim


internal wastegated.



stage 1 1/2 turbine is also proposed, to get early spool up.

thoughts of this style? this guy can build up a unit with smaller turbine housing if needed.

That will work well, it's quite close (slightly larger) than the older stock wastegated turbos and with the smaller exhaust will spool sooner than what you currently have.
Does he have a ball bearing option?
 
I am in the process of deciding what diesel engine to place into an '87 FJ-60. I have narrowed it down to a Toyota 12H-T or a 4BD1T. After two days of reading this insanely detailed and informative thread I am not much closer to a decision.
The 12H-T is hard to come by and expensive, but it seems like an easy install.
I really like the idea of the readily available 4bd1T to IDS - 4L60 - AA 700r4 - TLC splitcase transfer case - H55, but it sounds like it can be quite a project... 88TLC could you please tell me how much (ballpark) I may wind up spending on a 4BD1T install, you can PM me if you like.

I must say Dougal you are one thorough guy :beer:...

Thanks for the help:cheers:.
 
Dougal...

have you dyno'd a "tweaked" 4BD1T? I thought I saw somewhere (either here or 4BTSwaps.com) that you thought a 4BD1T was capable of 1HDT type power.

~Brian
 
Dougal...

have you dyno'd a "tweaked" 4BD1T? I thought I saw somewhere (either here or 4BTSwaps.com) that you thought a 4BD1T was capable of 1HDT type power.

~Brian

Unfortunately there are no dynos in the town I currently live in, the nearest is around 250km away.
The other reason is I haven't finished playing around with turbos etc.

I do have a viaduct not far away which I know the slope exactly (civil engineers come in handy) so I can use that to get a single point of power at the wheels.
From that I know I've got 74kw at the wheels at 2000rpm, which accounting for 35% lost in the drivetrain is 520Nm at the crank (400ft-lbs).
That is far beyond a stock 1HD-T, it is more torque than a stock 1HD-FTE but the FTE has a bigger rev range so develops more peak power.

The only mods, a smaller turbo, more boost and more fuel.
 
4bd1t turbo - aftermarket

76 kw, is just shy of 100 HP at the wheels, so like 130 hp engine? what is your equation to determine this, by just driving up a hill?

will be trying a couple turbos, it seems inevitable to test, compare, and find the performance out of this 4bd1t with the best turbo.

one is from blaastperformance.com . it is a T3 with a 50 trim, .50a/r turbine, with a stage 1 1/2 turbine wheel that supposedly spins up faster. attached is the compressor map. this will likely max out at 190 hp. i will be very happy if I can get that!

the other is a gt2860r. this sounds like it has a larger .60 a/r compressor. can someone describe what is a disco pancake? this turbo is perhaps on of them....
Fig3.gif
 
76 kw, is just shy of 100 HP at the wheels, so like 130 hp engine? what is your equation to determine this, by just driving up a hill?

will be trying a couple turbos, it seems inevitable to test, compare, and find the performance out of this 4bd1t with the best turbo.

one is from blaastperformance.com . it is a T3 with a 50 trim, .50a/r turbine, with a stage 1 1/2 turbine wheel that supposedly spins up faster. attached is the compressor map. this will likely max out at 190 hp. i will be very happy if I can get that!

the other is a gt2860r. this sounds like it has a larger .60 a/r compressor. can someone describe what is a disco pancake? this turbo is perhaps on of them....

The formula I use is quite complicated, it includes wind resistance (which cubes with speed) and the force needed to resist the slope. The good thing about this particular hill is that it's steep enough to make the wind resistance a very small part of the required power. So even if I got the area or Cd value badly wrong the differences would be small.
The biggest factors are the vehicle weight, slope and engine power.

My engine was rated around 135hp stock (100kw) at 3000rpm, the 2000rpm it pulls up that hill is nowhere near peak power. I estimate I've currently got around 170-180hp, mainly restricted by the exhaust.
The torque that I currently have at 2000rpm, if the engine produced that same torque at 2800rpm then it would produce 200hp.
My rev limit is 3600rpm (stock) but I rarely ever use that.
 

Users who are viewing this thread

Back
Top Bottom