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Turbo an n/a


benkei
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Have many people turbo'd an n/a? What's the general opinion of this? Succesful? More trouble than it's worth? I mean adding a single turbo, not a TT conversion. What is needed? Full engine rebuild, or is it farly straight forward? How much power can the n/a block take safely? etc?

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Have many people turbo'd an n/a? What's the general opinion of this? Succesful? More trouble than it's worth? I mean adding a single turbo, not a TT conversion. What is needed? Full engine rebuild, or is it farly straight forward? How much power can the n/a block take safely? etc?

 

USE THE SEARCH BUTTON MY FRIEND

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Parts in a Typical Basic NA-T kit (note this is not everything you need)

Turbo manifold (there are log and header types, headers flow for more power, but spool slower)

Wastegate (bigger you go, the more control you have and less chances for spikes and creep)

Downpipe (connects to your exhaust)

Intake pipe (connects from your turbo inlet to your filter or AFM)

Oil feed and drain lines (feed and drain oil to/from the turbo)

Turbocharger (large varieties of these, this is what makes boost!)

 

In the basic kit you usually run directly off the wastegate spring. Most kits keep you running on the stock compression levels (10:1 remember?) in the first "stage" or two, until you get serious about power anyways. This results in quicker spoolup and better off-boost response but you cannot run as much boost without risking serious damage to your motor.

 

-10:1 compression limits you to around 7-8psi without fiddling with your ignition timing (stock timing has a big "spike" of advance around 4000-4500rpms that will cause detonation if running more than 8-9psi and the base timing is not retarded 3-4 degrees)

-stock injectors will also limit you powerwise. I've seen several setups make OVER 400whp on the stock fuel setup (upgraded fuel pump) but its still best to upgrade them (and with a way to control them too -- SAFC, emanage, MAP ECU, AEM standalone, etc)... generally I wouldnt go over 350whp with the stock 330s.

-intercooler options, some kits come with some dont, most of the lower-priced ones dont and you are left to fend for yourself in the intercooler arena... you NEED one to run more than 5 or 6psi reliably

 

What you REALLY need for a well balanced kit

-strong turbo manifold, either a strong cast unit or a strong (IE 321 Stainless Steel) tubular header manifold... Dave H's manifold runs via Weld Els and it is VERY strong and beefy. His manifold is more of a hybrid, not really a log and not really a header.

 

-turbocharger to suit your powerband preferences (a later discussion perhaps?). Most people go with a T04E or PTE style turbo that makes around 400whp at 10psi of boost.

 

EDIT: Thanks for suprapunk pointing out something: If you are building your own kit: Ensure that your exhaust turbine lines up with your manifold Like make sure its a T4 hotside and a T4 flange on the manifold, and make sure you have the correct hotside outlet as well to mate to your downpipe (v-band, on-center, etc)

 

-35mm wastegate, Tial or HKS brands are good stuff. Many kits are running 38 and 40mm gates, which is fine, they cost more. Depending on how much power you'll be making with your turbo, you need to decide what to run unless a kit-maker already picks one.

 

-fuel and a method of controlling that fuel to supply enough for your power needs. On more basic setups I recommend the Emanage blue. Affordable and can tune your car very nicely. Most basic kits can make good power with MKIII Supra Turbo injectors. They are also top feed (but low impedance, need resistor box or inline resistors) and denso style but flow 440cc instead of 330. The Lexus V8 AFM modification is affordable and can make the 440s easily tunable with a simple fuel controller.

 

-a FRONT MOUNT INTERCOOLER. Do it once, do it right. The sidemount jobs cannot compare with the Front mounts other than being harder to see. You can pick up good quality units off ebay for under $300 these days.

 

-A 3 inch downpipe and 3" exhaust system! At least 3 inches all the way back if you can. Turbos need FLOW, give them a bigger exhaust and they will spool faster and give you MORE POWER.

 

-GOOD spark plugs and good conditioned ignition system (get a new rotor and cap for your distributor pronto!). NGK 3330s and NGK 6097s are both great plugs, they are pregapped at .031 which is perfect for turbo applications under 19-20psi of boost

 

-Oil feed/drain lines properly sized. Typical setup is -3 or -4 AN feed with a -10 (no smaller) drain line. Garret turbos require much less oil than most people think; and dumping high pressure (60psi+) oil into it and then having a small return line blows the oil seals on the turbo very quickly. You want NO flow resistance on the return line. You can do this by having a BIG return line like a -10 or use a oil-line restrictor (can pick them up at atpturbo.com). IF you buy a premade kit that comes with a oil-line kit then don't fret, its already been tested and setup with the turbo you'll be running from the kit.

 

Keep in MIND!!! That all of this is how to get power reliably out of the MOTOR. The transmission and the rear end are completely different subjects. Your stock clutch WILL NOT withstand more than 300whp and last for very long. Your stock transmission WILL NOT WITHSTAND more than 400-450whp for very long and driven hard (your mileage may vary).

Autos are very different from the stock 5-speeds. Do your research on driveline modifications!

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NA-T

Pros:

-You already have the engine

-If you blow it up you can find a replacement longblock for 300-400 easily and parts everywhere.

-The non-vvti bottom end with a headgasket to lower compression can easily handle 700+ rwhp RELIABLY.

-For around 2 grand possibly less if you take the time to piece everything to you can have a nice NA-T setup and already be single turbo, rather than doing a swap and still having to convert to single turbo later down the road.

-If you already have turbo and car experience you can do this in a weekend.

 

Cons:

-Distributor gets in the way with larger turbos on some manifolds.

-Intake manifold sits on top of the engine

-Stock compression is really high and must be lowered to run higher boost 10:1

-Large spike of timing advance at around 4500rpms.

-Stock fuel is limited by 330cc injectors, however u can find 440's and a LS400 MAF relatively cheap

 

1JZ-GTE swap

Pros:

-Smooth powerband and power delivery with the stock twins

-7500rpm redline

-Speed density (no MAF)

-Coil on plug

-Cheaper, however, with the price drop in NA-T kits this isn't always true especially if you have to pay a lot for shipping.

 

Cons:

-Replacement parts are harder to find

-Uncertainty regarding the condition of an imported engine

-Aftermarket parts can be hard to find, however this is changing.

-Less displacement as a 2jz.

-Lots of wiring. You have to extend the entire harness because its RHD.

-Stock twins limit you to low 300rwhp?

-Becuase its a swap youre going to run into a lot more problems you didn't expect.

 

2JZ-GTE swap

Pros:

-Oil squirters on the pistons. This isn't really that big of a deal though and no NA-T people have ever complained about lack of oil squirters.

-Lower compression stock

-Larger aftermarket. (same as Supra TT)

-Coil on plug

 

Cons:

-Engine is MUCH more expensive and for the extras you get, not necessarily worth it. You can swap fully turbo a GE for the amount you would spend to swap a GTE.

 

Tranny limits

 

Non-turbo automatic (A340E) - 325-350 depending on who you ask with a good cooler.

Non-turbo 5-speed (W58) - 400-425 with a good clutch.

Soarer automatic - high 300's with a good cooler.

TT Automatic - 400?

TT Getrag 6-speed (V160) - 1000hp+

MKIII Supra Turbo tranny (R154) - ~600?

 

Note: The aforementioned automatic transmission's ability to handle the stated hp levels is much more dependant on driving style. Power stalls and brake boosting build up lots of heat and combined with not giving the transmission fluid time cool down between hard runs will cause the clutch packs to break down much more quickly.

 

 

The basic differences between the GE and GTE (not comparing either VVTI editions):

-Most obvious difference to anyone familiar with engines is the TURBOS. The GE has none, thats what the 'T' in GTE means.

 

-Another is the style of intake manifold, the GE has a manifold developed for more torque development in the lower-part of the rpm band vs the GTE's short runner type. The GE doesnt have more torque; its just that it develops more than it would if it had a GTE-style intake manifold. Hope you knew that.

 

-Compression, the GE runs a 10:1 compression ratio and the GTE runs a 8.5:1 compression ratio. The differences are obtained through a thicker headgasket (.2mm for GE vs 1.6mm for GTE) and lower compression pistons on the GTE. The higher compression allows the GE motor to make the most of its power since it lacks turbos to begin with.

 

-Injectors and Airflow sensors, the GE runs 330cc top-feed high impedance Denso-style injectors and uses a Karman Vortex air-metering sensor to read how much air volume is being injested. The GTE runs 540cc side-feed low impedance injectors (though uses a resistor pak to raise the impedance for the ECU's sake)... measured through a hotwire MAF sensor. The GE's airflow restriction is around 450hp from the stock AFM and the GTE is around 650-700hp depending on several factors.

 

-The heads are slightly different. Some say the GE flows better than the GTE, though no concrete numbers have come from a flowbench to prove it. The GTE motor has larger intake ports on the head whereas the GE has larger exhaust ports on the head. You make your own decisions.

 

-The exhaust manifold and intake manifolds port spacing and studs are completely different and will not work with one another unless some machining is involved with the manifolds themselves. There are people who have successfully grafted the upper part of the GTE intake manifold onto the lower part of the GE manifold.

 

-The GE motor runs a distributor-based ignition system with spark plug wires and a single coil. The GTE runs coil-on-plug ignition with individual coils for every plug. The distributor gets in the way somestimes of the turbo intake pipe

 

These are just motor differences, there are many little others such as oil squirters, oil feed/return lines, transmissions, etc.

 

Now onto Similarities:

Both the GE and GTE bottom ends are VERY strong. The only difference being the pistons themselves. Thats right, the rods and crankshaft are the SAME parts!!! The 2jz motor itself was DESIGNED to be turbocharged from the beginning and is built VERY strongly from the factory. No one yet knows the limits of a GE setup, though there are several 1000whp setups on the GTE with the stock bottom-end. Dave H uses a GE motor and ran a 9sec 1/4 mile time with the stock GE block ( a spare 220k mile motor to be specific!)

All in all, it is very doubtful that you will need to build your motor when designing a NA-T setup unless you're gunning for ridiculous amounts of power. The stock cams are roughly the SAME.

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Thats a nice write up Miko, was it lifted from NA-T forums? There are quite a few errors though...

 

-Large spike of timing advance at around 4500rpms..

2JZ-GE

 

Why is this and what effect does it have?

 

I'd have thought this only applies if you're using a piggyback ECU (fudging signals to the stock one).

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Was going to turbo my n/a by getting the whiffbitz turbo kit, but looking at the totel cost to make sure that nothing will happen to the car, i have found that its just not worth it to be honest, i have decided to go for a TT conversion with BPU, not only am i looking at 400bhp, but also in the long run it will be worth it and i wont have any trouble, which i would have had with the turbo kit on the n/a.

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-a FRONT MOUNT INTERCOOLER. Do it once, do it right. The sidemount jobs cannot compare with the Front mounts other than being harder to see. You can pick up good quality units off ebay for under $300 these days.

 

 

I thought the SMIC (upgraded one especially - see CW's one) could actually be better due to the forced air into it, unlike the FMIC which hasn't got great forced flow? The side ducting is much more efficient at getting the air through the SMIC than the gap in the front bumper getting to the FMIC.

 

Just what I've read quite a few times (I'm no expert), and also the FMIC can lead to overheating issues more often?

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Just fitted a FMIC to a customers car and the thing is unbelievably BAD, over a third of the core tubes are masked by the bumper and lower lip, the ducting has to be binned, the air steel pipes bent and unclipped and the thing is solid mounted so you just know the brackets will work harden and fracture off in time. And no, it's not some Ebay thing, it's a kit from a "Well Known" Jap manufacturer. The core itself is horrible, too. No way is it going to work as well as a new SM.

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