Which turbo to replace twins?

I'm about to get my Valve Stem Seals done and since this is a turbos-out-job I'm strongly concidering getting my twins replaced with a small single. Couldn't you just see that the twins gave up after paying hundreds of £ for taking everything apart the week before...

So, as I'm satisfied with my current power level (390bhp) and I want to avoid getting injectors, new engine management and so on, what would you suggest?

I have been suggested a GT35 which should be a straight bolt on (+manifold and some oil hoses), is that right?

Do I have other options? On turbobygarret.com I see several different GT35's, which one is applicable?

Where do I get a specific list and a good price on whats needed?

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Check my for sale thread everything is there:d

But seriously - and your thinking very much along the lines of the reason I went on the long road to being single, its nothing to be sniffed at

Turbo side is only a small, perhaps a 3rd if even that of the whole single setup, fueling, management, brakes and making sure everything else is up to the job(vlv stem seals is one of them)

If you dont want something insane, I'd go for a GT30R or a GT35R

Some say a GT30R size tubby aint worth the hassle but setup right it is, the whole power delivery and setup is far superior to those stock twins

But you need the cash though, its expensive - 10K expensive minimum

You'd still need some form of engine management/fuel control even if you're not changing injectors.

Why not consider the PHR street kit ... set up with an MAP ECU and drop in injectors, no need to go the stand alone way

But, considering the fact the intercooler, clutch and fuel pump upgrades also cost money, the option of simlpy replacing the OEM stock twins shouldn't be put away.

No single turbo is a bolt on. You'll need a manifold, intercooler pipes, intake, injectors, engine management, wastegate, downpipes, etc etc. You're looking at £10k for a proper setup.

In any case you can change the valve stem seals without taking your turbos off - or in fact much apart from the cams. See Tony's extremely comprehensive guide in the tech reference bit of the site.

Damn, i was expecting funny replies.

Am I missing something, the valve stem seals do not involve taking the turbos off from the threads I have read???!

https://www.mkivsupra.net/vbb/showthread.php?t=49859

Well, you can do it without taking the top of. It is a bit risky business and demands special tools. I havent been able to find anyone wanting to take that job on. Also when taking the top off everything else in there will be renovated.

I was told, by my quite skilled mechanic (has done A LOT of work on MKIV and 2JZ), that it would be possible to replace the twins with a single (and he mentioed a GT35, i think) without having to change engine management, injectors and so. If I dont want to move beyond the 400ish bhp, why would a FMIC be needed when my SMIC works nice with my current BPU setup?

Also, where can I find info on the possible singles? Looking at fx garrets site it includes a lot of different turbos, and its kind of a jungle when I havent been looking at singles or turbo purchases before... Which fit the soop, whats the difference (whichout having to compare efficiency maps and so)

See kits I can supply here http://mkivsupra.net/vbb/showthread.php?t=159420 and the different turbos available here http://mkivsupra.net/vbb/showthread.php?t=159939

I wouldn't recommend fitting a single kit on though without upgrading the fuelling and ECU. The stock ECU is mapped for the sequential turbos and although it may run with the stock ECU it would be potentially dangerous to do so.

Well, you can do it without taking the top of. It is a bit risky business and demands special tools. I havent been able to find anyone wanting to take that job on. Also when taking the top off everything else in there will be renovated.

 

I was told, by my quite skilled mechanic (has done A LOT of work on MKIV and 2JZ), that it would be possible to replace the twins with a single (and he mentioed a GT35, i think) without having to change engine management, injectors and so. If I dont want to move beyond the 400ish bhp, why would a FMIC be needed when my SMIC works nice with my current BPU setup?

 

Also, where can I find info on the possible singles? Looking at fx garrets site it includes a lot of different turbos, and its kind of a jungle when I havent been looking at singles or turbo purchases before... Which fit the soop, whats the difference (whichout having to compare efficiency maps and so)

All turbos are universal - to an extent

The majority of kits for the mkiv ARE bolt on - in the nicest sense of the word i.e no custom work needing done, but tbh, think you need a lot of reading to do at this stage, your questions mimic a thousand other threads

The majority of kits for the mkiv ARE bolt on - in the nicest sense of the word i.e no custom work needing done

A lot of the US kits are designed to fit LHD US Supra and need modifications to the IC pipe to clear the steering column on a RHD Supra.

I never asked for a custom IC pipe and mine fits my setup perfectly, the steering column is close, but like 2-3inches close!

Joe knew I had a j-spec 6speed, perhaps he incl. a rhd specific pipe but I doubt it

I have seen pipes that flow the route you describe, but his IC pipe goes down and away from the steering column, can't see it fowling even on a different manifold

Regardless, this part aint particularly needed though, the majority of turbos can be clocked to utilise most IC piping for the stock setup

My PHR IC pipe needed cutting in 4 sections and rewelding to clear the column. Also had to shorten the mid pipe by around 4 inches for some reason.

My PHR IC pipe needed cutting in 4 sections and rewelding to clear the column. Also had to shorten the mid pipe by around 4 inches for some reason.

Very strange, I also have a 4inch PHR midpipe here I bought to cut up to put another muffler inline with my system, measure it up against the Full Race and apart from the angle that the DP meets its the same length, whole system mates perfectly to the HKS Ti

How long ago was that?

As said ... do a search on the forum and you will find all the answers you need.

One thing is for sure : nobody will encourage you to go single with standard ECU, injectors, fuel pump and IC.

If you want to drive your Supe for a long time ... go single the proper way or let it be.

IMO, regarding you hp goal, stick with the stock twins.

unless you are not scared of chucking in excess of 10k+ to fully spec your car and have it running perfectly and have money left over to replace older parts that are now going to wear out faster, I would just get a set of new stockers from nic

Ok, thanks a lot guys. Just heard that the stocks are such a B I T C H to work with and replace that I was better off going single.

I'll do all I can to keep the twins then

 

I was told, by my quite skilled mechanic (has done A LOT of work on MKIV and 2JZ), that it would be possible to replace the twins with a single (and he mentioed a GT35, i think) without having to change engine management, injectors and so. If I dont want to move beyond the 400ish bhp, why would a FMIC be needed when my SMIC works nice with my current BPU setup?

 

yes you could run your stock smic at this level and possibly your injectors with the fuel pressure cranked up (550's would be better) but you cannot expect the stock ecu to control a single turbo when its programmed to do 2 sequential turbos, you would get a big dollop of fuel at the 4000 rpm change over point and then not enough at the top end, i dont know of anyone who has done this, however at the level of power you are talking about an Apexi SAFC would be more than enough but you would have to pay to have it set up properly on a dyno

yes you could run your stock smic at this level and possibly your injectors with the fuel pressure cranked up (550's would be better) but you cannot expect the stock ecu to control a single turbo when its programmed to do 2 sequential turbos, you would get a big dollop of fuel at the 4000 rpm change over point and then not enough at the top end, i dont know of anyone who has done this, however at the level of power you are talking about an Apexi SAFC would be more than enough but you would have to pay to have it set up properly on a dyno

Does that work with a J-spec? Running MAP instead of MAF?

Does that work with a J-spec? Running MAP instead of MAF?

yes, well it does with mine