3sgte Gen 2 or 3! Help Me Decide!

[8Bit]

Hi, I have a 91 sw20 with a gen 2 with 150000 miles on it and i think the turbo bearing went cuz when i get on it and boost gets to half and then starts to screech and snd stops building boost. my question is should i rebuild the turbo and do some mods or should i swap for a gen 3. my goal is to have a nice street machine that retains lots of stock but is not necessarily a daily driver. I want to make numbers in the horsepower range of 300-325. What would I have to do to my gen 2 price and parts wise? Same with getting a 3rd gen that i found for $2,500.

[MR-3sgte]

after 300 hp the 2nd gen 3sgte and the 3rd gen 3sgte are the same motors with a few different parts. I have almost 200k on my 2nd gen and im planning on rebuilding it with aftermarket pistons and rods theres 700 dollers im also getting the block blue printed and possibly bored over theres another 700 now you have yourself a built bottom end now you can go with a different turbo set up and not only boost more but dont have to worry about blowing your internals. Im not gonna tell you what you should decide on but you have my opinion. Why buy another motor for 2gs when you can rebuild your own and make it more solid. Turbo rebuild kits are also avalable and if you do it yourself its quite cheap.

[CJMR2T]

Thats kinda a tough question to answer...
First off, your HP goals, are they wheel number of flywheel number? Both engines are capable of that in stock form. If you engine is "good" (by this I mean, good compression / very low leak down, and good oil pressure without having to run overly thick oil) then I would say stay with the stock engine as it would be cheaper. A better turbo and some tuning will get you that power.

If you engine is on its way out, then you have a choice either rebuild it or go Gen3 but rebuild will probably be a bit cheaper though if you have the ability to do it yourself. If you dont trust yourself building the engine, then a Gen3 swap will probably be cheaper....

With a correctly sized turbo and a proper tune, there is no reason why a stock engine will not handle 350hp (hell, I've personally seen 3 stock engines push close to 400 reliable cause they were very well turned.) Toyota's OEM turbo engines are very robust from the factory. 200hp per liter is not a problem for them if tunned correctly..

[8Bit]

That HP # would be at the crank but thats not to say I wouldn’t want more power than that I just felt like that was a good starting point, sorry I was not more specific , but I guess my real question would be if I you were to have about 3000 (not saying I want to spend that much) to put to either a swap or a rebuild what would you do. My motor runs great with good compression and all and I feel like if it aint broke why get rid of it for a gen3, but after reading through the forums it seems like the 3s have an edge in the minds of people who have had experience with both gens. If the motor I have now would be capable without rebuilding or replacing any major internals what parts would I need and what turbo should I go with (I like strong midrange), should I have my CT26 rebuilt with a new housing and a trim or go and get something new. so to sum up if u were in my shoes and your turbo has **** the bed and something needs to be done with it and while you were at it you wanted to increase the power how would you go about it. Thanks for the advice so far

P.S. what would you say the limits of a stock gen2 motor

[CJMR2T]

Me in your shoes??? That depend, do you know what I know and have the ability to do what I can?? By that I mean about 15 years experiance in fabrication and welding and more the 15 in engine building. Also about 15 years in dealing with forced induction...

If it were me, I would stay with what I have just because of my abilities and know-how thus making it a lot cheaper or can go further with the same money.

This does go against my car per-say cause my 91T has a gen 3 but thats only because I got it that way. I cant take credit for the swap / setup (thankfully though cause its not a very good setup to say the least)...

I do agree that in many aspects the Gen 3's do have an edge, but for what your wanting, I dont know if you would really need to go to a gen 3. Remember, every part, every engine, every setup and so on has its advantages and disadvantages and everything is a trade-off or compromise with something else.. A build / setup for strong top end power will have to trade off with a weaker low and mid range where as a setup that gives a good strong low and mid range will have to trade off for a weaker top end... This is all why Vtec, VVT-i, VVTL-i, ect.... is the big think with modern engines. Having variable valve timing has the benifit of give the best of both worlds...

When it comes to turbo selection, I personally would go with a totally different turbo the stock and upgraded stock CT's do work well but there are better units out there. The same goes for the manifold. The stock manifold does work quite well, but thats not to say that there couldn't be a better unit.

A ball bearing unit with a divided entry turbine and a properly grouped manifold would be the best setup but to do this, you'll probably have to build a custom exhaust manifold...

By doing this, you can tend to run a bit larger turbine trim and housing A/R without the lag that would otherwise happen for size increase thus raising the VE (volumetric Effiecency) of the engine in the top end. This therefor allows for more power for the same boost pressure while still retaining a decent midrange where as your typical large turbo setup will tend to be very laggy thus reducing midrage... A perfect example of this is my car. The person who built it must not have had any real knowledge of a proper turbo setup. Its a Gen 3 engine with a crappy OBX stainless manifold with a turbonetics 62-1 turbo. It is a ball bearing unit but the turbine is too big and the house is too. This setup runs like an N/A engine until about 4000 rpm when it can finally produce about 4psi. Even then, it still cant even hit 10psi until close to 6000 rpm. It takes off like a scolded dog or a rapped ape at around 5500rpm and holds all the way to 7000 but it still sucks to use as a daily driver. From 5500 to 7000 it is far stronger then a friends stock setup gen 2 running 12psi in that same range... This is because the ratio between intake manifold pressure and exhaust manifold pressure is closer to a 1:1 ratio at 10psi intake pressure, my exhaust pressure is only at about 11.25psi where as on mikes care, at 12psi intake, he is at a hair over 18psi in the exhaust manifold... This is hurting VE in the top end and explains why at a lower boost my car is far stronger. Again, the my car still sucks for mid range. I swapped out the huge .96 A/R housing for a much smaller .58 A/R house and spool is noticable better, but with it, the compressor starts to surge cause it is way to big too so I cant wind out the engine or ever hit even 10psi lower then 5000rpm....

The new turbo setup is still to be chosen cause Im unsure of the route I want to go...

With all that being side, If you entend to stay below 400hp flywheel, with a good setup, you should be fine with the stock engine. Like I said before 200hp per liter shouldn't be an issue for a stock engine as long as you have a proper tune done and a proper setup. The only downfall is you stated that you like a strong mid range. By that, my guess is you want the engine to be strong in the 3000 to 5000 range correct? This might be a limiting factor with overall peak horsepower...

[CJMR2T]

Sorry for the last post being soooo long, I tend to ramble....

In short, you can go with things that have been tried and tested, but thats not to say that there isn't better out there. I really boils down to what you want and how much your willing to work at getting it. Always remember though that most things are a trade-off for something else...

Think about the typical usage of the car, choose wisely, and do not set outragous goals. By that I mean, if the car spends most of its time as a DD where its not under boost ofter, dont shot for high HP cause it'll tend to sacrafice midrange but at that same token if the car will be spend more time on a track, dont shot for a strong mid range as it will tend to hurt you in the top end..

I've seen it way to many times that people dont size a turbo correctly to the typical and entended use of the car / engine....

[MR-3sgte]

dude dont go half ass go all out. Once you go fast you only wanna go faster trust me i owned a 500 rwhp N/A z28 and i always dreamed of it being supercharged

[Bak@EMSPowered]

Gen3

[brianbooth]

I tend to agree with Baktasht. If your Gen2 has that many miles on it and your goal is in the 300hp range, the Gen3 is going to be the easier solution. Much more power than that you're going to be looking a bigger turbo so if you want more power than what you say, it really doesn't matter which engine you have because you'll have to replace this expensive core component anyway.

[Texas_Ace]

I will just toss this out there:



http://www.pballandmore.com/images/T...-dedicated.jpg

That is on a BONE stock 3rd gen with S252 turbo. Only other mod is an ebay SMIC.

That same setup/motor will be getting a stand alone and some meth as soon as i sell my 300zx and i plan to go for more without touching the motor.

[8Bit]

Thanks for all the advice so far. i have decided to go the gen 3 path. in about 3 or 4 months i am going to start and ill be posting pics of the whole thing.

[SW20jiro]

Wheres the pics?!

Its been a year!