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I'm such a moron.

Posted: April 15th, 2005, 11:00 pm
by Flashpoint2
There are so many turbos, i have no idea what I'm looking at. I must spent 2 or 3 hours a day reading through these forums, trying to get a grasp of all the terminology for turbos. WHat's the difference between a T3/T4 and a T4? A vj-11 and a vj-14?? Why would someone choose one over the other?



[Watch the lanugage]

Posted: April 16th, 2005, 9:20 am
by babyblueMX3
there's a lot of things you have to look when buying a turbo..
difference between a t3/t4 and t4 is simple. The t3/t4 uses a t3 turbine with a t4 compressor for faster spool ups. a t4 as both t4 turbine and housing. t25<t3<t4<t66 (this is just an exemple) the bigger the turbo the biger gain you'll have but greater lag is present. I don't know much about the vj turbos.you might want to ask a 4cyl guy..I think they came with bpt's and engines like that.
Another thing to look out for are the A/R (area/radius) a bigger area/radius gives you bigger top end power but you trade that for more lag. and vice versa.
You can also look for the trim size. different trim as different maps for compressor effeciency..
Anyways this is just an over view..There's a lot to know.
First start by determine your goals (what whp you looking for, top end?or low-end?, etc.) and then learn how to read compressor maps. and you'll be good to choose a correct size turbo

Posted: April 16th, 2005, 11:44 am
by What
If you search the internet you'll find tons of sites with turbo information. Although still try to get an idea of something specific to the vehicle.
Decide what engine you are going to turbo (1.8, 1.6, 2.5 whatever), a horsepower goal, if top end is more important than bottom end, and then ask for some suggestions from guys who play with a lot of turbos. Decide if you're going used or new, and so on so forth.

VJ11 is bigger than VJ14 if what someone told me is correct.... I haven't played much with the little Mazda turbos though.

As one budget option - turbos like the 14B from a turbo DSM would provide good spool and good potential on a 1.6dohc.

Posted: April 16th, 2005, 1:08 pm
by TEAMpK
I have a VJ-11 for sale if you are interested.

Posted: April 16th, 2005, 2:46 pm
by Flashpoint2
Well, i decided against the BPT swap, as the engine i have only has 108k on it, and it runs very strong. As a HP goal, i want to get to ~ 160whp, which really shouldn't be that much of a stretch on stock internals for the DOHC. I was thinking of using a turbo from an '88 626, i've heard good things about them.

What's the difference between say a 60 trim wheel and an 80 trim? just CFM? This car is still going to be my daily driver, so from what i've read getting a smaller turbo would be better, as there's not as much lag. I don't want too small a turbo, though because i don't want it to have to work at max capacity all the time.. i still need my reliability.

Posted: April 16th, 2005, 3:01 pm
by 93SOHC
purchase the book "maximum boost" by corky bell, available at amazon.com

Posted: April 17th, 2005, 1:00 am
by facko
i just got done turboing my dohc and i used the vj-11 (thes ones from a 626 or probe). im still getting little odds and ends for it but ive got it running and i love it. it didnt hurt my gas milage much (getting like 20ish mpg in city). i THINK the vj-11 is good upto 17-18 psi? maybe closer to twenty iono...i read the smaller vj-14 has been run by some guys on here around 14-15 w/o problems so those are just my estimate numbers 8) but pretty much what im saying is ur not gonna be over working it. if u wanna know nething as far as what im using or what not feel free to pm ( P.S. if i really screwed up on my numbers dont scold me too hard i am just a junior member :( )

Posted: April 17th, 2005, 1:49 am
by Flashpoint2
I'm planning on keeping the stock internals, so i probably won't go past 10psi. Maybe next year i'll put forged pistons/rods in, but for now i don't have the time, money, or energy to spend on rebuilding the engine. I don't want the fastest MX3 on the planet, by any means.. i just need it to be quicker than 105 bhp will allow :D

Posted: April 17th, 2005, 1:13 pm
by freyguy_412
Someone on here told me in a past post that a RS motor runnin a turbo at stock boost (6-8psi) will hit 160hp even if the turbo is the only mod. You kinda figure that turbocharging the stock motor is just like having the B6T motor, but with a better head. I also seen a guy who is running 13 psi on the stock internals, and is putting down over 230hp. As long as you tune the puppy up it will be an awesome daily driver. Nobody can just slap on the turbo, mash on the throttle and really expect the best results.

Posted: April 17th, 2005, 1:17 pm
by facko
reading that makes me wanna find a dyno and take my car there now :(

Posted: April 17th, 2005, 4:09 pm
by Flashpoint2
Hmm.. well I'm originally from Nova Scotia, and i do know a guy there who has a portable (if you can call it that, you need a 1ton truck) Chassis dyno, so once i've complete this, i'll just take a week off and drive home :D assuming I can't find anyone with a dyno around Niagara. I'm definitely not going to do this halfassed, but I do want it done as inexpensively as possible.