18G question
 

So after some thought and research I'm thinking of going with a Blouch 18G because I want a good overall turbo for my car's current functions. (my DD, fun on twisty back roads, and most likely some sparse track use) But im not gonna do pistons now and from what Ive been seeing a 20G may be pushing the limits a bit considering its my DD.

As many of you may know I had a Dominator 3 but recently sold it because I dont think I want to run that much power quite yet. Ive decided I want to be in the mid 300whp range (trying for at least 350, but if its a bit over or under its w/e) Mostly I want a good responsive turbo that will hold boost far better than the VF39 and that will hit my power goals, im talking usable power here.

My car has basically maxed out the stock turbo and injectors already. its running a bit over 300whp (EL headers, uppipe, TB exhaust, Intake, turbo inlet, Perrin TMIC, Cobb AP with my custom precision tuning map on it) So setup wise I need a turbo and fuel mods. Walbro 255 is obvious, idk what size injectors now (was gonna run 850s with the Dom 3, but this may not need that much, suggestions plz :) ). Im staying with my top mount, but i am gonna go external wastegate.



So I said all that to say this (sorry about loving to hear myself talk): Theres all this talk of the TD05 and TD06 housings and the 7cm vs 8cm hotside etc and what is good and what isnt. Basically, yes I wanna know which configuration is the best idea for what I want, but I also would like someone to explain the differences in dynamic characteristics between them plz (just for knowledge sake)

So far what Ive gotten from looking around is that I really need the 8cm housing, but ive seen some say the TD05 is good and some say to get the TD06. now with blouch, the TD05 18G has a TD05 turbine wheel but has a TD06 Compressor housing. Whereas the TD06 18G has both in TD06 form. what would be the difference between those 2 turbos?

thanks

Call Blouche, or FP. Get it straight from the horse's mouth, and I gaurentee either one will talk your face off. Then come back and report what you heard and what they advised you to do. The only thing I want to contribute is that you can still run 850s if you want. Since you're not going to be using 100% IDC, you could purchase the bigger injectors now and just scale them down with your tune and an AFPR, and then when, and if, you go to something like the Dom 3, you already have the parts you need. FWIW, I've DD'd my DSM with an FP GREEN 20G on a 17 y/o 140K+ engine, and if I remember correctly, TROLL has a similar set-up to mine on his Sube, plus two doors and minus the mileage and good looks :). The only things pushing any limits are your tune and your right foot.

Measure twice, cut once.

Thats deff on my to do list. I wont be buying for a little while, but im trying to put a solid agenda together, so im starting now.

But I would like the input from knowledgeable people on here. cuz it serves as a sort of record I can refer to or w/e

ur advice on the injectors is quite solid, and I'll probly wind up doing that. But what would be the size that would fit that setup (like be at a good % of its duty at the level i would run here) ? i just wanna now my options.

I don't know enough about Sube tuning to comment on that, but ultimately it's all in your tune. You keep adding some fuel and some timing and lean it out til you knock, then reevaluate and repeat. If you're not doing your own tuning, I'd consult your tuner, too.

Ya Im deff taking it to get tuned and installed. I do some of my own work, but after the intercooler and the turbo inlet (which we did the hard way in 11 hours), Ive decided to have big things professionally installed from here on. lol

my main question here is about the turbo specs and the differences they cause in vehicle dynamics.

Why not look into 20g?

I haven't ruled it out yet. It just seems that the 18g may be best for what I want from the car. (See above for what that is)

if I'm wrong plz explain tho

Whats ther year and model of the car?

An 18g on a 2.5l is absolutely worthless. You want 350whp? Get the 20g. You will not be happy with the 18g on your motor. To give you an idea we recently tuned an Sti with just a TBE injectors and inlet. Fully catted downpipe (2 cats) and a 20g and made 340whp. Plenty of power and uber fast spool.


I seriously think 99% of people who own turbo cars have no idea whatsoever what lag is.

Ok, so why would the 18g be bad on my car exactly?

I know the 20g can make more power and all. but Ive also been hearing that at the range im looking to be at, the turbo wont be at its efficient range. Whereas the 18g would. What can the 20g really accomplish that a TD06 18g cant for my purposes?

I mean this is gonna be my last power mod while its my dd. if I do anything else to it I will build the motor and run a rotated kit, but that will be years from now and idk if im gonna keep it or move onto something else when im outta school. so for now, im not building the motor and i want something that will stay reliable. Ive heard the 20Gs push the limits of my motor and I have more mods now than ur previous customer did so "in theory" my car should make much more power with the proper tuning etc. (its not that i wouldnt like 390whp, its that i know thats gonna push the limits of my motor)

Dude, you should totally go 16G.

thanks.........


serious responses plz, i asked some legit questions and id like some legit answers.

If u think/know im wrong then plz enlighten me here thats why i made this thread to begin with, so that those who know more than me can share the knowledge.

The 18G is going to be like your VF39 but with 20-30 more hp. The top end is gonna drop off like a rock. Its to small of a turbo for the 2.5L

The 20G is going to be 40-50 more hp and is going to pull to redline. Its the perfect blend of fast spool and top end on the 2.5L.

If your afraid of blowing it up with the 20g tell your tuner to keep it on the safe side, and turn that **** up when your ready.

^what he said. You probably won't be all that satisfied with the gains of the 18g. Go 20g and just keep it conservative.

Even with the 8cm housing it'll drop off that bad?

Turbos confuse me.

there TD05 and TD06 18gs each with 7cm and 8cm hot sides.

And theres also TD05 and TD06 18gs each with 7cm and 8cm hot sides.

What is the difference other than the 20g flows more air obviously, but shouldnt a TD06 18g with the 8cm hot side hold boost just as well (or nearly) as the TD06 20g with the 8cm?

Somebody please explain this stuff...... please.

TD06-18g-8cm will make 340-350whp on a 2.5l with 360wtq or so...it won't drop off at redline nearly as badly as a VF-39. My buddy runs one.

what supporting mods is that with?

cuz im gonna run this. full exhaust with EL headers (1 cat after the DP and a very high flow muffler), intake, samco turbo inlet, ur old perrin Tmic, and i'd be adding the 18g, ewg setup, walbro 255, injectors, and an ebcs, and plugs if needed.

just curious as to how his setup compares with mine. thanks

Here ya go:

http://blog.somecar.net/

he was the only STi I knew of with a turbo upgrade on stock internals and now he's had to go to forged too. on an 18g.

ahh...he upgraded to a 2.5r.

he ran the 18g for about 10k then or so before upgrading..interesting...guess i better call him and find out what happened haha.

TD06 8cm 20g and be done with it. You have the 2.5L block to spool it quick and its gonna pull till the very end making full power from 3k rpm till 7k rpm.

All the other turbos you mentioned in this thread are you masturbating till you get the big 20g.

ndubz - you notice you are jumping at people in the thread who support your initial conclusion rather than listen to the people who understand your goals and have built a ton of cars for customers to meet those goals. Then later, they have seen how those customers react long term to the power mods and the capacity of the turbo.

Listen to Ryan. Pretty prz.