3sgze?

[Malcolm]

btw I have no doubt the bottom end is up to the challenge, as Warwick already pointed out the crank and rods are the same as the 3sgte, and the pistons will just be higher compression versions of the 3sgte ones. Infact I intend to eventually build a 3sgte using a gen 2 3sge block, head and intake manifold, but st185 ecu and sensors etc for my girlfriend's TA22. The high compression will make give it excellent low rev torque and drivability, and since it wont see over 8psi or so detonation is unlikely to be a problem, but ONLY because I'm going to run it with the 3sgte ecu

[Mr Revhead]

the ecu factor is a good point

but if using an aftermarker ecu not applicable.

high compression is good, with a good intercooler not a problem.

the 3sgte runs over 10psi in stock form, a sc14 will run 8-10 psi on stock pulleys. so i reckon thats doable on a 3sge, and would make more power than a lower compression engine.

but i have know idea how the 3sge pistons would handle boost. having said that toyota doesnt make crap pistons.....

if it was done right with the right bits, i reckon a 3sge running a sc14 would make more power than a 3sgte running a sc14

[Malcolm]

the 3sge runs over 10psi in stock form, a sc14 will run 8-10 psi on stock pulleys. so i reckon thats doable on a 3sge, and would make more power than a lower compression engine.

I'm not sure what you mean about the 3sge running over 10psi in stock form? Was it a typo and you meant 3sgte? If so that isn't true, on a stock gen 2 you will never see much over 9psi. More power is debatable though, as the higher compression means you have to heavily retard the timing to prevent detonatiob

[Gx71man]

well here's my reasoning for why I think the 3sgte would be a better starting platform:
1 - a 2nd gen 3sge is map sensored. If you want to run positive manifold pressure (aka boost), you will have to fool the ECU somehow, otherwise it will go into limp mode around 1psi.
2- a 3sgte ecu has mapping to retard timing as boost levels increase, helping to prevent detonation. You can get the same result crudely on a 3sge by retarding the base timing. Easy, but it also has the effect of making the car sluggish off boost, aswell as degrading fuel economy
3 - the compression ratio of a 3sgte is better suited to a boosted set up, so in hot weather you are a lot less likely to get detonation
4 - a (gen 1 & 2) 3sgte has the advantage of having a fuel system that will easily supply a 300hp motor
5 - cam profiles and timing are also designed to suit a boosted set up. Wont go anymore into that aspect because I'm not sure on the exact differences, or the theory behind why they're different.
6 - already has an intercooler, if you mount the SC in the AC compressor position it will be very easy to plumb up to the stock top mount

but at the end of the day it's up to you, those are my reasons for why I would do it that way, but I understand many people would prefer to go for what is percieved to be the cheaper option, a 3sge is probably going to set you back atleast $700 less than a 3sgte, and most wont see past that fact when considering the cost of the project

Hmm Well said!
I would take this idear into consideration, as he has made a couple of good points.

[Adamal]

Mr Revhead: Your wording sucks then

Told you AF knows what he's on about!

[Mr Revhead]

haha yeah typo. im good at them

no i dont think you will need to retard the timing that much. maybe to 6 deg. (which is where i run my aw11) certainly not to the point where youd be losing power.

i was under the impression sw20 3sgte's run 10-12 psi *looks at al*

a good intercooler would be esential, and water to air would be the go.

i still think higher compression is the way to go, and with the right tune reliable. maybe water injection would be an idea.

oh and im not saying allfours is wrong, he does have some good points, my debate isnt about the ecu or fuel system though.

[Malcolm]

no i dont think you will need to retard the timing that much. maybe to 6 deg. (which is where i run my aw11) certainly not to the point where youd be losing power.

well as soon as you start retarding timing you start losing power, unless the car is already detonating. Why do you run your aw11 on 6 degrees? I have heard 4age's that have been turboed without ecu modifications usually run in the vicinity of 0 degrees timing!

i was under the impression sw20 3sgte's run 10-12 psi *looks at al*

not stock, with a decent exhaust off the turbo they will get up to atleast 10psi normally, sometimes more. Boost cut is at about 13psi.

i still think higher compression is the way to go, and with the right tune reliable. maybe water injection would be an idea.

Well the simple fact is that boosted engines perform better with lower compression, this is why you don't see factory turbo cars with compression ratios up around 10:1. Infact the 8.8:1 that the st185 runs is considered to be high compared to other turbocharged set ups. Might just have a look at what the 4agze's run.

oh and im not saying allfours is wrong, he does have some good points, my debate isnt about the ecu or fuel system though.

Well in that case perhaps a 3sge block running 3sgte electronics would be an idea too, but still only for lower boost set ups, and who wants to have an engine that at only 6psi is already on the verge of detonating? A bit of safety factor is advisable if you want a reliable engine.

[Mr Revhead]

mine seems to run fine at 6, no sign of detonation, although i dont have a knock sensor... yet. so the ecu is probably pulling it way back.
stock is 10deg base.


seems i was put wrong on the 3sgte boost then!


no, boosted cars dont always go better with low compression, the higher compression you can run the better. the lower the compression, they higher the boost needs to be, therefore creating more heat and reliabilty problems.
so a high compression low boost set up has its place, look at saab.
the st215 runs 9:1, the 4agze runs 8 or 8.9. mines on 9.4.


stock engines can take a lot more than they are given in stock form (well most!) its all in the tuning... and the set up, as i said a good intercooler is essential

dont take this as meaning i think you can slap a sc14 onto a 3sge running a stock efi system... youll need the 3sgte injectors and an aftermarket ecu etc. id be very suprised if it cant be made to work safely while making good power. more power than a 3sgte running the same s/c set up even. cause itll have more compression


where the 3sgte has the advantage, is you can run more boost, but to get the best from it, you probably need somehting other than a sc14

[Al]

not stock, with a decent exhaust off the turbo they will get up to atleast 10psi normally, sometimes more. Boost cut is at about 13psi.

Yes stock. Once the t/vsv is energized you should make 11.8psi of boost. Mine ran at least 10psi. Usually 11psi. Bone stock. In winter I even hit the boost cut which is ~12.5psi.

Its just that there are so many f$%ked mr2s around that people think they only boost 8psi or so.

[Malcolm]

6 degrees timing is retarded from the stock 10 degrees BTDC, which is why you wont be getting any detonation, i bet if you bump it up to 10 degrees it will run a lot better, although yes I did just remember that your's is sc'ed 4age! so maybe not.

I still think that you will get better top end from a low compression setup than from a high compression one, and you will also have more scope for improvements. What's the point of going to all that hassle, even installing an aftermarket ecu for 6psi? But anything I say is simply conjecture as I have not done any comparative testing between high comp + retarded timing vs low comp + more advanced timing, and my knowledge of the physics and chemistry behind cylinder filling, proper burning of air/fuel mix, ignition timing etc is nowhere near indepth enough to being to speculate

[Malcolm]

are you sure your's didn't just have a leak around the actuator or a faulty actuator? because i have never seen any gen 2 3sgte boost that high stock, including one with only 26,000km on it. most are around 6 or 7psi with the vsv disabled and 8 or 9 with it open

[Al]

Well when you disable the t/vsv on the sw20s it goes into low boost mode obviously of 6-7psi. Everything I've read on mr2oc.com about it says 10-11psi stock when the t/vsv is energized.

It did 14.3 @ 98mph dead stock with a slow 2.1 60ft. Running pump gas, factory paper air filter in stock airbox, full cat. converter, stock exhaust.

Maybe mines just a freak

[Malcolm]

mr2oc...well....you know what american's are like at exaggerating things. Hmm I wonder what my MR2 will do with just an exhaust and intake

[SIDE_FX]

ok i know i going to get yelled at called an idiot and burned at the stake for this but nearly any favtory (not shaved or modified internally before forced induction) N\A engine can handle boost 10psi or below IF u run extra fuel to stop it from knocking but not too much as there are cases where this can cause knocking, also running too rich ur car will be slower than without the turb/SC, the next issue is to make sure ur ecu doesnt know its running boost, map clamp, safc i think it called, any thing to briong the mapp reading down, if u can do this your N\A engine will take the punishment not for ever but longer than a month, only things that put rods through blocks is seizing while running and exseive exsesive power jump like from 200bhp to 550
this is my theory anyway andd is proven by many 4ages and many d15amy mates one especially so i think a 3sge will take the S\C[/quote]

[Liloss]

Thanks for the input guys. All_Fours you have some bloody good points man. I would look into the idea of using a SAFC if that would do it, otherwise a 3sgte loom and ECU. 10PSI would be ample, i dont want a fast car, just something thats a bit of fun to drive around in. I would most certainly look into a water to air intercooler set-up. I looked at engine prices...3sgte = $1500 3sge gen 2 = $500. Should be able to have a 3sgze running for $1500 were as a 3sgte would still need wiring in,exhaust made and fuel pump.

as i've said guys, im looking for something different and it dont have to be fast, it is after all my daily driver ATM lol. My Aw11 is going to be my fast car

if my memory serves me right theres a manifold thats made to bolt onto the SC14?

[Liloss]

just had another idea, i remember seeing a twin carbed 3sge gen 2, thing was freakin fast, was a race car though but was crazy, now could i combine that with my SC? so i'd have a twin carb SC 3sge? or is that really stupid?

cheers

[deaf_rattle]

if you really want to build a car to someone elses taste, because you want them to go hey thats really cool, come finish my car and ill tell you how cool it is every day.

build a car/engine because you want to.

find out all the facts and information first, unless you have lots of time and money to find out all you need to yourself.

and remember these words.

DO IT ONCE, DO IT RIGHT

[RomanV]

So, just out of interest, (and wildly off topic!) How is your car coming along anyway?

[Adamal]

DO IT ONCE, DO IT RIGHT

Golden words.

[deaf_rattle]

the supra?
Its sitting at the moment with the rego on hold.
The front bumper is coming off soon for replacement with a facelift/p type item

the engine is coming out and being replaced with a fully rebuild bottom end.

hopefully i wouldve saved enough for the turbo kit im planning on getting for it in time for when the motor goes back in, which consists of a huge fmic, 50mm external, tubular exhaust manifold and t4 turbo.

i am in the middle of sorting out a daily driver, so the supra may get a roll cage and have the rear half of the interior stripped (still debating about this)

So expect to see it up and causing chaos in the next few months.

Aiming to unleash it again in sept.