Hayes

Can anyone point me out to the major differences in the engine construction of the two?

I know the that Turbo has a lower compression ratio and forged internals, but are there any other differences?

I have thought about piecing together some parts to turbo my 85, so I have more power through the hills, and I am trying to gather as much information as I can.



Also, for the people who have 22RTE's, how does the Turbo affect the offroad capabilities? Do you boost when you are going fairly slowly, or just at the higher speeds?

AxleIke

You boost at high RPM's, so, it doesn't matter what speed you are at.

It doesn't affect it at all. Just more power if you rev it up.

Hayes

but do the rpms get high enough to cause boost when climbing rocks, or only when hill climbing and stuff?

JamesD

The pistons in the turbo engine are cast just like the N/A engines except they are lower compression.

James

abecedarian

cylinder head chambers are different (but heads can be interchanged)
pistons are dished on the 22rte (to lower compression)
oil passages in the block are slightly different, but they are not incompatible and there's a casting in the exhaust side of the block for the turbo oil return.

in general, the 22rte is below the 22re in power when revved less than around 2000 rpms, and provides around 50% more power than the 22re above 3000 rpms through redline.

as is the case with most turbos, the 22rte is, by design and such, not going to offer any more power from idle to low/mid RPM's than the 22re can, and at lower rpms may offer less power due to the lower compression ratio.
on the other hand, the 22rte design is quite capable of accomodating a supercharger which will compensate for the low-rpm doldrums (aka "turbo lag").
so now you have another option to consider.

Hayes

I have always considered a supercharger. I think I can piece together a turbo system for less. I only plan on about 6 pounds of boost, and since the 22re makes more power off the bat (against the 22rte without the turbo on), Lower boost can help me make more power on hills and the like. Basically, I am just thinking out loud.


Also, has anyone seen a centrifugal supercharger used on these engines?

abecedarian

I feel you'll be in the realm of 'diminishing gains' if you try to turbo a 22re without significantly changing things, with regards to a 22rte in comparison.
In particular the fuel management. Rumor has it that the 22re can deal with approximately 3-5 psi boost without mods, however that also will require adjusting the timing (retarding it) to prevent significant detonation (since the 22re ECU is not programmed to deal with boost/timing requirements), which will put you almost on par with a 22rte with regards to 'off-idle' performance, and consequently will not provide the same peak power a 22rte would.

keep in mind the 22rte ECU is programmed with the turbo in mind, and the 22re ECU is not. So given the higher compression ratio in the 22re and having to retard the timing to prevent detonation, you end up in a "net-zero-gain" situation, where either one performs approximately as well as the other in most situations.

just a thought....

Hayes

I was thinking about tuning it with the MegaSquirt, which would allow for timing adjustments. I see what you are saying. A supercharger would be sweet, but with a high price tag.

86RETturbobuggy

The 22RET has several differences from pistons to intake egr, exhaust header, oil drainback in block, oil feed line, larger radiator with water cooler return lines for turbo as well as a water feed line off the back of timing cover for turbo, head is totally different injectors are larger ecu is different dash cluster is different, many differences however re and ret parts are interchangeable. I'm running a stock 88 re bottom end with the ret head exhaust intake etc and running 10psi boost at 3 degrees timing and truck runs excellent pulls very well with 4"lift and 33x 12.5x 15. I havent had a chance to pull fuel pump but I'm assuming it as well will be higher volume then stock 22re pump. As far as when boost kicks in as per the question. It comes on very early in the rpm range and is dependent on engine rpm and nothing to do with speed. 2000rpm and it starts spoiling and hits 10psi almost immediate making great trail power as well as hiway. A 5speed with turbo would be less useful in the rock crawling as fluttering the accelerator will nit allow boost to build as it will with the automatic tranny and constant throttle. Rule of thumb. Custom turbo setups to run reliably takes $ and knowledge of how a turbo works and what's needed to make it work properly and not melt and or crack your pistons due to lean conditions and or uneducated desisions. Hope this helps all the young ones thinking slap on a turbo n way we go. Not quite that simple. Unless u just like looking at it with hood up

Jkelley429

iTrader: (1)

doesn't less compression mean less power? If you were to get some higher compression pistons, and shave the head wouldn't that increase the power? im planning on building a 22rte and im just trying to do some research.

86RETturbobuggy

Ideally you want lower compression for a turbo application as the airs forced in and with high compression you will get detonation, and piston cracking and melt down starting over 10psi boost. For stock high comp pistons you can boost but only moderate levels not exceeding 10psi without a standalone and even then lower comp pistons will allow boosting upto 25psi (400)hp on the stock ret engine with proper fuel management. I'm running a stock 22re high compression block with the ret lower compression turbo head with injectors ecu mass air meter hiflo pump and rising rate fuel regulator at 10psi and about 3-5 degrees timing. Pulls very well reliability has been great. Fuel mileage ahhh about 20$ gets me 120kms with 4"lift and 33" rubber. But she does dance very nicely

Jkelley429

iTrader: (1)

ill definitely remember that. thanks 86RET.

Tiyoda87

Hey 86ret, are you running a stock toyota turbo and setup? If not what do you recommend?

86RETturbobuggy

Hi, yes mines with factory setup, however you can go with any turbo you want really with a t3 base, they all will put out high boost just different intervals of rpm and vary on how fast the turbo spools meaning a t23 turbo will spool faster and will boost at an earlier rpm then a t4 turbo will t4 will The t3-t4 turbo will boost later in the rpm but come in harder and at a cooler temp allowing a bit more psi boost and help from a larger inter cooler. A t3 turbo @ 12 psi should feel like a t4 turbo at 7 psi setup right. Keep in mind the amount of psi boost you want to run us dependent on proper fuel management. 6-10 psi with and aftermarket rising rate fuel regulator and timing aprox 2-3degrees should be safe. A size up on injectors(360cc) and larger fuel pump would also benifet. Thats for stock 22re. The ret bottom ends are apparently solid upto 350-400hp at 25psi. again this kind if boost is not attainable without stand alone computer, big fuel and proper tuning

Jkelley429

iTrader: (1)

if i had to choose between the rte head and the rte block, which do you think would be most important? im not going to be able to get both in time for the build. i also found a garrett t3/t4 .57 trim turbo on CL for $110 dollars. guy says he had it on a 240sx and ran it at 12psi. he also said he sent it to garrett for a rebuild. Is this a good deal?

Tiyoda87

Ok I see thank you for the information. So you are just running the stock ct20 then? A lot of people I have seen and talk to seemed to swap the turbos to the ct26,g3, or g4's because most say the ct20 are junk so I have just been trying to figure out which way to go with mine. I just bought a 86 4runner, motor needs rebuild, but just trying to figure out what to do with the turbo.

86RETturbobuggy

Yes the stock turbo's don't have a long life span. The garret is a good choice just check shaft play. There should be next to 0 play. Also keep in mind ideally you want a turbo with internal waste gate and oil cooled. If you go with water cooling you may want to use the rte timing cover as it has a water feed line off the passenger side that routes behind engine to the turbo and the rte also comes with a larger dual core rad with the turbo water cooling return line in top right corner of the rad. If you had to choose between a rte block or head I would run the block rte timing cover and go with a stock head. Compression on the rte is reduced with the low compression pistons big plus, also you already will have the oil feed line off the block for turbo as well as the factory return oil feed on the block. The rte head also has different chambers for lowered compression as well but you can get away with a stock 22re head just make sure you use a (MLS) head gasket don't cheap out on this part. Keep an eye on egr differences through the head years. If you use a stock 22re block you will need to customize the oil pan and weld in a return spud for the oil drain back as well as T off on the oil sending unit on passenger side of block for the turbo oil feed. Always use good oil and maintain changes. Dirty oil is a turbos worst enemy. Hope this helps.