I was reading through the archive and came across a TT question and read many of the responses. I thought they were interesting and some kinda contraversial.

Here is the link:
http://www.2gnt.com/dcforum/DCForumID16/193.html

First thing on my mindwas where was I. Anyway a couple q's got my attention. One was that a twin turbo setup would increase Heat and underhood temperatures. I'd like to say that this is TOTALLY incorrect. There are 2 primary reasons(that I can think of) that twin turbos are used. The 1st is the Speed/Power that a TT will give you. You can have twice the power at the same boost as a single along with 2 tiny turbos that both spool usually twice as fast as 1 big one. Some say there is pressure loss. So far I think that's debateble The other is that the exhaust heat is slightly distributed between the 2 turbos and better absorbed by its various metal instead of (and less likely into) the surrounding underhood air actually keeping things cool.

Back to my 1st point about a TT advantage is the power. What if you wanted 600HP on tap, instead of after lag, when a Diablo(or some other rediculously priced COMPLETELY impracticle utterly worthless daily driver unless you plan on pick n' up a girl - car) pulls up and you feel the need to smoke him(or whatever - I would just like to have the power). A Big T6 making 600HP is probably only going to see the boost in 2nd or 3rd(which is fine) but that means the power isn't immediately on tap and would require some sick lag with all that pressure on such a big turbo at like 5000rpms. Anyway the only way to fix that would be to have 2 turbos one right after the other like on the Supra. 2 turbos spooling at the same time(on the supra turbo 2 turns on at 3500rpms).

Anyway I'm just curious as to whatcha guys think of a TT on such a small 2L?

Skrilla
'97 Base Talon NA
"Technology: The Only Replacement for Displacement"
"Peace and Turbo Grease"

http://members.dencity.com/xtdsm



this has been done to a 4g63 car ( I can't recall who did it, but it has been done )

why it's not that widely done.

1- if you go with sequential setup (one turbo spools b4 the other one) it's gonna cost you way too much money to have it done right mostly doing the R&D.
2- a lot of people with Supras do a single turbo conversion (for the fact that one big turbo will give you more power than 2 small ones) RX7s too.
3- when it's done to a 2.0l DSM or even other in-line 4, most of the time you will have clearance and space problems (2 turbos, 2 IC piping, 2 turbo inlet pipes, 2 down pipes (or one Y shaped)


If you go with parlor set up (one turbo per 2 exhaust runners)
1- headers easily crack since you will have one turbo hanging on two runners of the exhaust manifold (you can always build a bracket that will support the manifold, but again we are talking about very small engine bay.

2- since you will be pushing each turbo from 2 cylinders only, no matter how small the turbo is, you will always have more lag than you would hooking the same turbo to all 4 cylinders.

the bottom line, it can be done, but it will cost a lot to do and to maintain ( oil lines, coolant lines are going to be doubled with a twin turbo set up )

so what's the why to get as much power or even more with less lag?

Big ass turbo+NOS (have the NOS activated in lower RPM ranges to help you get of the line and help the turbo spool up.
Or small turbo to get you of the line fast and then run big shots of NOS to get you to the end of the track.

Skrilla, I have not read the article you gave an URL for, so if you see anything repeated, just ignore it.

Adel <----- loves to talk turbo stuff :)

...I was confronted before about what would spool the turbos. I was thinking that the hot side of each turbo would getting all 4 runners. They hit T1 then leave the Hot side of it and hit hot side of T2. No lag and true sequential. The supras remember are not true twin sequentials, they are simultaneous after 3500 rpms and not before. It is also easier for them to run 1 big turbo because of their displacment, their 3L is an entire 1L larger(that's 1/2 our engine!). 3L for a T6 isn't bad at all really. Even for the 13B RX-7. It "displaces" 1.3L but has(and performs like a 2 stroke motorcycle engine) 2 powerstrokes for evey one of ours, thus performing like a 2.6L.

Skrilla
'97 Base Talon NA
"Technology: The Only Replacement for Displacement"
"Peace and Turbo Grease"

hey. do the turbo's you all were talking about have other names such as the big 18g or 20g? i was searching for them using the names you posted up and couldn't find anything. any help? thanks


Matt

Guys,

What about having a smaller T1 (say T25) and then a larger T2 (say T4) for a sequential setup. The smaller one will boost at 2k -4.5k rpms for dialy driving and then the bigger one will kick in at 5k rpms. The smaller could be used to "boost" the larger turbo for a no-lag feel.

Would that work or just be too crazy? Boost controlling, electronics, etc???



"RACECAR backwards is RACECAR!"

Kory
korynguyen@yahoo.com
Happy Honda Hunting!

What about a supercharger and a turbo setup would it work and would the engine hold? I think anything could be done it just the $$$ factor.

...to use a T-25(from bustrblue1) and HRC's 16G BB. Maybe on 2 different WasteGates(just for the MAX adjustability even though it's not necessary) and control everything I want with the AVC-R. It will let you select rpm boost and different boost dependant on the gear. So if I want low end grunt (around town driving) I can have it and just change it up if I want high rpm power, or both since I will have two turbos on two differnt WG. As for the underhood room. I don't understand why everyone thinks there isn't enough room. There's plenty, and even more if you wanted some cutting. I also have my batt. relocated so a filter could go there for the "cold" side of 1 of the turbos.

Skrilla
'97 Base Talon NA
"Technology: The Only Replacement for Displacement"
"Peace and Turbo Grease"

I don't see how you could possibly need anything more than what a 16g BB would put out at bottom end? If you want to go even more crazy for faster spool, look into an IHI turbo by apex-i or the ones they use in the 16G killer kits. But seriously, i have the crappier version t3/t4 from one of the first star kits made that had the shittiest cast manifold made. and honestly, it spools up slow, but i have no problem ripping first gear loose, or second for that matter. any faster spoolup and traction would never be found. and if you need more spool up, just downshift. but god, doesn't a twin turbo on a 2.0 liter, or even if you stroke it out seem a little like over kill? Supra's, RX-7's, etc, all switch over to a single turbo. If you watch an options video, you won't see a twin turbo. And these are street cars. Any drag car you are looking at won't either. It just seems like a hell of a lot of money that could be spent elsewhere on shit like engine management, and internals, or even a 50 shot to get it spooling.


jason
95 GS Turbo

LAST EDITED ON 19-Mar-01 AT 10:49 PM (PST)

I have to agree with Jason... Heck my turbo starts to make
"positive pressure" at 2300rpm. I have a S16G. And it was only
regulated to 10psi... therefore it hits max boost at about 3500rpm..

Is there a reason beyond the "coolness" factor that anyone
would want a twin turbo? the only reason I see myself putting on
two turbos is to shove much more boost into my engine...And
that's not gonna happen (40+ psi)...Especially since its only at 10psi right now...

Also don't forget that in a "sequential" setup, the second turbo
is a big restriction for the first turbo, so regardless of the
setup the small turbo will spool slower than if it was all alone.

Sadly among the "general crowd" out there, there are lots that
think twin-turbo is faster just 'coz of the "twin". I always get
the reply.. "Oh but its not twin turbo". Heck one guy told me
that his car was very fast because of its "quadruple exit, dual
exhaust" Basically its an old-ass Grand-Am with two mufflers....
HA!

My favourite was when my friend and I pulled into a movie theater
once. My friend was driving his 2G GSX (12.8sec) and a guy came
up and asked him how come his car was so fast (we had just
whooped on them on the way there).. My friend just said, "its
turbo"... What was the guys reply? "You mean you don't have VTEC
in there?"

Guy
RS_Guy



13.9sec @ 105mph passes
w/ Blown piston rings,
on Stock Internals
at 10psi Boost....

I totally agree with RS_Guy.. A twin turbo setup on a 4-banger sounds pretty wack anyways. Just thinking about it seems like a waste of resources. This is why we have t3/t4 hybrid turbos, so you have the spool characteristics of the smaller T3 turbo, with the top end power of a T4.
My question is "How fast do you really want to go?"
if you are planning on making a 600hp+ racecar I would advise you not to even bring it to the street.

later!

i king of think it's a good idea. if i could afford it or knew anything about it, i would also consider doing the same thing. i mean you wouldn't have much problem with turbo lag and when it both spooled up, boom!! that would feel great to just be gone like that! i don't think he would have any probs with it as long as it's installed right. you can't really have too much power. i'd love to have a lot more, and i plan to. over the summer though. later

Matt

What's wrong with having full interior(even though I'm not but I have subs) and having the most power Even carve up the competition w/o breakign a sweat. I always here this: There is someone who is always faster. Sure that may be impossibe but I want to be that "someone". 600HP on one turbo will most likely spool in the top of 3rd. I don't want sportscar power('Vetts, Porsches, Stock Supra) I want supercar stomping power(Modenas, Diablos). Then you guys will probably ask me. Why? Why all that power. Why Not? The Ferraris and Diablos have it, why can't I? My strongest argument is the fact I want 600HP daily, all turbo. Why not bring it to the street? There are several others. I HATE the thought of NOS. Why juice it and throw away money for refils for low end torque - rediculous. I appreciate the input but seriously for 600 ponies(sh!t maybe more) you need two turbos with a puny 2L. To answer some other questions: An IHI turbo is $$. This twin turbo setup is only costing me $3000(not including electronics that anyone would buy anyway). Expensive, NO way. They aren't all brand new(turbos BOV and couple others) but more cost effective and bang for the buck. Being the Supra afficionado I am, I will say this about single turbos - 3L. Its big enough to push very large turbos with minimal Lag. As compared to us we have 2 cylinders less and 1L less - BIG difference (but this is old news I'm not the 1st to tell). No there isn't pressure loss with twin turbos either, only in the way its plumbed together. 2 turbos inline with each other don't lose pressure and will only require a foot(if that) of extra turbo piping - No pressure drop. They also run cooler. Twin intercoolers will cause more pressure drop in this setup. Remember RX7's and Supras are not true sequential turbosystems, thus the pressure drop. Supra owners can do a free mod to convert to True Twin Sequentials that adds more power and lose less boost. The turbosystem efficiency is less than 2 psi drop. Thats better than most single turbos. Do this - check out the Suprastore(.com) and search their TT Kits to replace the factory ones. BTW an aftermarket Single turbo Conversion is CHEAPER not necessarily better, and tend to be "peaky" in power and torque. Here's an excellent ex. of a TT HKS Supra Dyno:
http://store5.yimg.com/I/supra_1629_1462577

that's a beautiful sight:) and vertually flat between 5K-7.5K on torque(perfect for 6trh speed hwy cruzin' and strength)

Realistically a T3/T4 is good with decent spool but it still takes a while, and is a compromise(the key word) I want something closer to perfection, more complex that can handle the power and be fully flexible. Even though we are FWD the Quaif will do much to help on some 225 series tires. My aim is not to brag about 2 turbos but to have a lot of power that can only be used on a small engine(so that means no big turbos) and spool quick enough(or soon enough) to put to the ground. 600HP in 5th gear would be damn nice instead of waiting for boost because you rpms can't sputter out enough exhaust gas to spool mr. T51 or even T4. They are fast but at 30 psi the turbo isn't fast enough and you need to many revs to create the power. 2 turbos at 15psi could easily handle that job(Perfect!), wouldn't you say? Sh!t that could spool by 4Krpms MAX to redline. Bust out the ol' AVC-R for good boost control and boost gear selection then cruz and call it a day. Nice torque in 3rd creepin' along in the city.

Please don't tell me to get some POS American V8. Have you checked the Lemon law on Crustangs and 'Vettes lately?

Skrilla
'97 Base Talon NA
"Technology: The Only Replacement for Displacement"
"Peace and Turbo Grease"

hmmm..more power to you if you want to go this route..i am gonna stick with a haltech, internals when i find the downtime, a built cylinder head, high revs, a ported turbo, and some big ass injectors..and well..it should make for some fun

jason
95 GS Turbo

LAST EDITED ON 21-Mar-01 AT 05:23 AM (PST)

Twin turbos can work in one of two ways.

a- sequential - ala 300ZX and 3000GT - both turbos spool similarily, take 1/2 the cylinders, and are sized equally.

b- non-sequential - ala RX-7 and Supra - one small turbo is used for spoolup and one large turbo is used for top end.

Looking at your post, you want to go sequential? What turbos would you intend to use to make 600hp?? Think about your choices for a minute. What would produce enough CFM's. I think you would have to use something like 2 BIG 16G to get in that range. So lets think of the lag of one BIG 16G. It spools 15psi around 3500-4000rpm depending on the setup, and this is with 4 cylinders of exhaust pressure. OK. Now with two, divide the pressure between the two, hrmmm. I think you will still have the same lag problems. I do not think you solved the lag problem with the power level you are talking about. With the 2.4l stroker converions, you have probably cured some of the problem right there, but I do not see it havinb better spoolup than sya a single TO4E BB slapped on there with less complexity. Oh, don't forget about the space issue. If you look under the hood with just one turbo, you would see what I mean.

MuRiX
97 Eclipse GS HRC Stage II
And a whole lot of other mods...
89 Accord LSi - yes it's mine :(
http://murix.home.icq.com/index.html