SanJoRX7

So, it looks like there's a couple turbo options out there for when mine decide to go south (probably not for a while, but hey, gotta know what I'm gonna do when it happens). The three options I'm aware of are:

1. Replace stock twins with the same. Pros: Standard level of reliability, no worries about overboost, etc. Cons: Standard level of power/hp, difficult to go faster than stock.

2. Upgraded stock twins (i.e. M2 ball bearing twins, etc.). Pros: More hp possible than stock, potentially better reliability. Cons: Costs bux+, not as much potential as single.

3. Single turbo (T78, T88, etc.). Pros: Huge hp gains possible Cons: Costs bux++, need other things to make this work right (IC, piping, etc), plus might not pass smog.

...All this being said, can anyone add to the lists of pros/cons? What about passing smod with upgraded twins or single? I'm under the impression that these will make it much more difficult, but I'm not sure for sure (those who have these please comment!).

Anyway, comments and suggestions are welcome...

Want2race

I have upgrades.. the ONLY reason id trade them for a single is less vac hosses! Besides that Twins kick ***!

PraxRX7

I don't know about pros and cons beyond what you mentioned...

But I do know that the upgraded Twin Turbo setup would kick ***, most 3rd gen owners just go with the single turbo for bigger HP numbers...but the twin turbo upgrade is a REAL challenge.

JoeD

im with want2race.....the only thing i like about single turbo setups is the deletion of vac. lines.

SanJoRX7

Bump. I am really interested in the upgraded twins and their ability to pass smog. I mean, my car will never be a drag car or a super track ride while I own it (which will be until my body is cold and dead), so I'm thinking for driveability and whatnot upgraded twins is the way to go. Any comments on smog in CA w/ these?

maxcooper

I think that upgraded twins would not effect your ability to pass emissions, but most singles require the removal of the air pump, which will have a significant effect. If you have visual inspections, I think the single would be a big problem.

Another con of upgraded twins is that you are likely to face boost creep problems if you have full exhaust (which wouldn't pass emissions, and thus might not be the route you'd take anyway). Keeping a cat, even a high-flow, would probably be enough to avoid any boost creep.

-Max

Jordan

I think getting a new stock turbo would be a good choice. You should also check out the old turbo, and see if there's any distortion on that. if so, that means the old one were not working properly, and so you might be happy with the new stock turbo.

mmaragos

Wouldn't you upgrade the wastegate too?

Anyone out there with upgrade twins that can comment on the wastegate? Or on any potential boost creep issues or experiences?

rxrx7

If you ask me, the decision lies in $$ and how much time you want to keep your car in the shop. Sound like you want the car for a fast street car so I think you should get the stock turbos or if you have the $$ the M2's are suppose to be nice.

Want2race

My turbos came with an enlarged wastegate. they cut the door off of them and welded a larger 1.3" door inplace! Its ported to 1.29" so there is almost no chance of creep with even a midpipe!!!
@ least i hope there will not be.. And im runnign a high flow cat so its not a problem @ all.

djantlive

How would a ported rebuilt stock turbo compare to the BB twins?

Johnny

since you stated driveability is number one..why not stick with stock twins ? The afterall will be those most responsive for everyday driving..Upgraded one are unproven in my opinion and we all know singles are dead below 3K.. you can easliy get 320-340 rwhp on stock twins..that's plenty for everyday use.

Pressurized

I, myself, am going to go with ball bearing twins. The reason I like these over a single is, the twin setup provides more HP at lower(evryday) rpm's.....you don't have the lag of a giant single turbo.

Both can be emissions legal easily, it just depends on what you want the power for and how you drive. If you want highway speed and pull, go for the single. If you want to zip about townreally quick, go with the twins.

The only downside to twins, like mentioned before, is they retain the "nest" of vacuum lines, which makes them a little more complex.

JoeD

M2 Ball Bearing twins spool faster than stock.

Johnny

I'll believe it when I see it..remember the wheels are larger, but the fact that they are ball bearing "should"???? offset that.

Nathan Kwok

According to M2, the ballbearing twins are so friction free, the wheels spin just by blowing on them. AND, a guy on either the list or the forum (can't remember) actually verified that! That doesn't necessarily mean they will spool faster than stock, but I'll bet they do. Regarding singles and smog in CA, I've never heard of anyone passing smog legitimately with a single. RP setup a T78 that passed the Texas sniffer, I heard of someone setting up the HKS kit to pass the Maryland sniffer, but never the CA sniffer. Obviously it won't pass visual either .

widebody2

for the guys who actually have the m2 twins: have you ever ridden in a big single? how much of a difference is there...say on the high way with a drop from 5th to 4th at 70 mph. i am hoping there isn't THAT big of a differnce because right now I am leaning towards the twins. please let me know if I'm wrong.

JoeD

the thing that i also dont like about singles is if not tuned correctly, there are embarrasingly low hp numbers. ive seen single turbo FDs dyno as low as 360 rwhp. that number is attainable through bolt ons with stock turbos.

typically, a T78 powered FD should make around 430 RWHP on pump gas at 15 psi. an FD with a similar setup but high flow twins should make anything between 400-415 RWHP.

you gotta realize, is it worth the extra $700-$1000 and all that lag for just a little more power up top??? i personally dont think so.

suganuma

are none of you considering smaller sized singles in these discussions youre having??

i dont get it.....a lot of these posts are kinda ignorant - not trying to be an ***, but i think lots of this would be cleared up if you went to single turbo section and read around or did some searches.

fact is a smaller single will simplify vacuum lines reducing headaches of sequential diagnostics, make more power at the same pressure, and a million other reasons that i think are worth it.

i DO like upgraded sequentials for the fact that they are UPGRADED meaning theyre better than stock in many ways. you can upgrade YOUR turbos to do what you like......just need to know what you want and how to go about it.

maybe im just rambling cause its late and im tired......but read up y'all.

good example single for all of you wanting stock like boost and spool up with the benefits of a single setup would be the apexi rx6 isamu setup. its very nice.

everyone needs to just figure out what they want as far as use for the car and power range and peak values and where they want those peak values and you can tune in your car for those variables as well as others.

i am planning on going single once i get the money. i think its completely worth it. SO....if you want some remanufactured twins with less than 10k on them next spring or so, shoot me a message.

not tryin to flame - so dont go blow up on me after this post.....

take it easy,

Cheuk in Seoul

My APEXi single spools as fast as and put out more power from 2000 rpms + on the dyno than a BPU FD with stock turbos. The response is the same until the twins starts the transition around 4000 rpms and the single just runs away at that point.

The smooth linear run away freight train feeling of the single is hard to beat.

Also don't forget the solenoid problems with the twins. Two seperate turbo control solenoid failures finally pushed me over to the dark side.

And you never have enough power just not enough tire:p
My 275's makes my single turbo just controllable for the street... I don't know what will happen now that the weather is getting colder.

Cheuk
93 VR R1
443 RWHP uncorrected, 417 RWHP corrected

Donovan

I was at M2 two weks ago and they had a set of the BB twins there. They do spin by just blowing on them, and not too hard. They come with everything on the stock setup so they are close to plug and play.That is if you can ever get ahold of M2. Do not send email, You must call and call and call................

JoeD

here is a good example of what i was talking about. 417 RWHP is attainable in an FD with all the bolt ons, plus a street port and upgraded twins. it seems like similar power is made by upgraded twins or a medium sized single. ill list the pros and cons of single turbos. i wont take power into the comparison becasue it seems to me that they are about the same.

PRO:
no more vaccuum lines and turbo control ****.
cleaner engine bay.

CONS:
turbo lag.
more $$$
need more engine management and tuning.
need new IC pipes or a whole new IC in some cases.
most single turbo FDs ive heard sound like ****, IMO.

JoeD

BTW, what kind of fuel management do you need for upgraded twins?? do you NEED to go standalone?? can a Pettit Unlimited ECU with new injectors/fuel pump handle upgraded twins??

hapa

If you've ever driven, or riden in a single turbo FD, then you know why single is better. True the stock setup passes smog, true the stock setup can make excellent power (almost 400rwhp), true the stocks are good on the street. But if you've ever felt the power delivery and the smooth power increase in a single, you'd never question the mod. There are many many people on this forum and the big list that have gone single, have you ever heard any of them say the wanted to go back? I don't think so. Twins are a better setup for some, thats why Mazda put them there. Before you decide for yourself, take a ride and see what the hype is about.

eric

JoeD

anyone?