2JZ-GTE Twin Turbos on a 2LT?

[raohamid]

Initially all of the exhaust is routed to the first turbine for reduced lag. This resulted in boost and enhanced torque as early as 1800 rpm. Approaching 3500 rpm, some of the exhaust is routed to the second turbine for a "pre-boost" mode, although none of the compressor output is used by the engine at this point. Approaching 4000 rpm, the second turbo's output is used to augment the first turbo's output. As opposed to the parallel mode, the sequential turbos provides quicker low RPM response and increased high RPM boost."

Thanks,
SK

I have read this paragraph at least 4 times. Its such a beautiful paragraph, the picture one gets in one's mind is bliss.

RKR

[SuhaibKiani]

I have read this paragraph at least 4 times. Its such a beautiful paragraph, the picture one gets in one's mind is bliss.

RKR

Maharaj kee JaiHo!

I do believe you can find the turbos around and rather cheap too.... But its gonna be quite a job to do a clean install. Nevertheless, does not seem all that impossible as long as you can make space in the engine bay. Some pics I found:

[GlobeTrotter]

Its difficult to set it up.. real hard work.. but once done.. if done right that is.. it pays its dividends..

Good luck with this project!

[pindi]

Instaling a turbo on a nonturbo engine is very deficult, because you have to increase your celender bore, other wise it will blow your head off ( not yours ).

[datpak]

why not a compound turbo setup?a smaller one boosting the engine and spooling a bigger one for top end.but i doubt a 2l has that much rev to use the potential.why not simply slap on a 1kz ct12b boost it above 1 bar and call it a day.

[MITSU_MAN]

@SK

You probably are really unhappy with that 2LT;)....to me it looks like you are bent on relieving the old horse of its miseries:P.....
Now going laymanish-techno......I guess a 2nd boost past 4000 (while the motor redlines at 4500) would be hard to handle by the infamous 2LT keeping in mind its past track record of busted heads.....rather would be hard for most diesels to sustain that kind of high rev range/abuse as a regular feature....don't you think so???? I'd go for a 1 KZ swap if I was a perfo buff and save up by trading in that 2LT while it still runs:D!

[Ghuncha]

as far as i know the twin turbo setup is a very complex, on both the exhaust and intake side, by complex i mean there are valves which route the exhaust and air where needed and when needed, all this is controlled by the ecu which in your case wont be there hence it will be near to impossible to get any or significant benifit

[imtishal]

If me memory serves me right.I saw a similar setup in a BMW 7 series diesel in a top gear episode.they used a small turbo to spool the bigger turbo.small turbo kicked in as low as 1500 RPM and main turbo kicked in @ around 3000 or 3500 RPM.Result is turbo boost as soon as u hit 1500 RPM and no turbo lag.But how BMW achieved it is another story.
Found the link
http://autospeed.com.au/cms/title_BMWs-Twin-Turbo-Diesel/A_2544/article.html

[syncview]

If me memory serves me right.I saw a similar setup in a BMW 7 series diesel in a top gear episode.they used a small turbo to spool the bigger turbo.small turbo kicked in as low as 1500 RPM and main turbo kicked in @ around 3000 or 3500 RPM.Result is turbo boost as soon as u hit 1500 RPM and no turbo lag.But how BMW achieved it is another story.
Found the link
Browser Warning

budget for the engineers at BMW for R&D: 1,000,000.00 USD

I'm afraid SK's would be short by a few hundred dollars.

[syncview]

I have read this paragraph at least 4 times. Its such a beautiful paragraph, the picture one gets in one's mind is bliss.

RKR

I'm sure you were feeling the turbos spool in your mind, one at 1800RPM and when you approached 4000 RPM you tightened yourself in place

[SuhaibKiani]

Alright...thats good going

Firstly to clarify, this is loud thinking on perhaps the only conceivable twin turbo panga with an engine that should not cause a major disaster (either emotionally, operationally or financially) if things go wrong. Alternatively, the same panga can be done on the 1KZT which will perhaps be better suited given its larger displacement albeit still 4 cyls vs 6 and much limited flexibility given electronic controls....

@MitsuMan: I actually really really like my 2LT for a number of reasons and never went for a 1KZT upgrade primarily because in this particular case, I never could foresee a significant enough performance jump to justify the cost. With a mechanical pump its also easy to vary between race and economy settings, which are both quite enjoyable with a little extra boost on the CT20 turbo. I do agree that the 4000rpm second boost is too high and perhaps getting the whole boost pattern shifted down by at least 500rpms would be the most interesting challenge here....

@Ghuncha: Are you sure that the valves are ecu controlled? From the photos I would have thought that they were mechanical with minimal electronics....

@imitshal: Yes, I believe the BMW sequential twin-turbos are actually where I originally picked up the basic bug from. The TLC200 (and some LWB 70s) have the twin turbo VD engines and I was surprised to see that the 2JZ has a sequential set-up as reportedly these were sprawled all over our kabaar markets just about a few months back. Thanks for the link!

@syncview: Actually, I am short by just those few hundred dollars that would be needed for the R&D here As a few friends of mine in college used to jokingly say about a friend from Ratta Amraal (Rawalpindi): "Talent ubhar raha thaa, ghurbat ne ooper se paaon rakh diyaa"

Some questions, I struggle with at this stage:

1. How can the JDM and the US market 2JZ-GTE's both have the same RPM ranges using two completely different sets of turbos?

2. What are the possible ways of lowering the overall RPM band on the 2JZ turbo set-up?

3. Can the same 2LT boost controller be made to work with the sequential set-up?

[saidhi]

"Talent ubhar raha thaa, ghurbat ne ooper se paaon rakh diyaa"

hahhaha, excellent quote, loved it

[Ghuncha]

@Ghuncha: Are you sure that the valves are ecu controlled? From the photos I would have thought that they were mechanical with minimal electronics....

yes i am pretty sure about the 2jz setup, you dont see any electronics but you see a lot of actuators whcih are electronically controlled, i have attached a picture of vacume diagram found under the bonnet of a supra twin turbo, have a look there are a lot of actuators and all of them are electronically controlled, have the workshop manual of MKIV supra too, in there the operation is explained, its more complex than one could imagine it, there are many modes of the operation of the twins, and its all electronically controlled. because of this complexity the later models of 1jz switched to single turbo setup(i assume)

[Ghuncha]

[Ghuncha]

in this ecu pin out you can see at least 4 vsv (vacume control valves, that controls the mechanical actuators) for the twin setup.

[hash4u]

i couldnt believe my friend when he said that with 2LT his cj7 starts to stall going uphill untill i saw it myself
they the engine was thrown out and replaced with a 5L engine which i think was a wise choice. power and economy and speed is fine as well.

this turbo panga is not worth it i think

[sherwan_88]

A CT8 blowing into a CT20 will give you a broader boost range and will start to boost as low as 1000 rpm. External Wastegates with manual adjustments and a blow off valve are needed.

[MITSU_MAN]

@SK

Well amigo, you'd be adding another dish on the menu list in not so distant future....''ROASTED PISTON" and at phajja's it would be served as......''PISHTUN FRY''!!!!

[sherwan_88]

@SK

Well amigo, you'd be adding another dish on the menu list in not so distant future....''ROASTED PISTON" and at phajja's it would be served as......''PISHTUN FRY''!!!!

Mitsu,
it would be "Mashed Pistotoes served with Glazed oil and Pisto raisins". haha :D:D

[SuhaibKiani]

Just a bit of what little I have gathered with my pangas:

• The 2LT does not sit too comfortably with the stock Pakistani CJ7 axles/diffs which are invariably the Dana/AMC 4.1 (10:41) originally for the high torque AMC 4.2L engine.

• Toyota apps of the 2LT have been with much lower gearing of upto 4.88s on the TLCIIs, Surfs and Hiluxs and even higher (5.32ish) with workhorse Hiluxs and Surfs.

• At the low end in Toyota apps, the 2LT relies on the lower gearing of the axles/diffs to haul its puny **** until the biggish CT20 turbo kicks in at around 1800-2000rpm and delivers boost up until close to the 4000rpm red line.

• With the high speed 4.1 ratios of the CJ7 the 2LT is quite the loser at the low rpms and hence struggles in real offfroad situations where at the end of the day it can never match up to the B series and KZ engines anyways.

• On the road, a good 2LT (new/II) conversion on a lightweight CJ7 can actually quite exciting. With a little extra fuel from teh pump and added boost from the turbo, you can actually give the big boys a good run for the money..... as long as you don't boil the water and cook things into a pistun curry with its rings

• On cracked heads, my view is that extensive use and abuse of a few things on have contributed to its nasty reputation: bad cooling, high speed diffs, bigger tyres. I don't think that there is an inherent flaw in the engine design otherwise Toyota would not have stuck to the basic design and it would not be one of the most common engines in Afghanistan and Baluchistan.

• A second turbo setup in sequence, without too much boost to add some grunt to the low end would perhaps be the best upgrade for an engine that is reportedly going to be available very very cheaply in the near future if not already.

......I take this stuff too seriously, I shoudl just buy a Pajero and give up dreaming of German cars