18g or 20g Turbo

[Talon64]

Ok well right now my 18g 6SL2 has bad shaft play and will be sending back to force performance to get fixed. (Hoping it will be free on 3k miles on it!) Right now I just got a SBR Bastard 20g TD05H to put in the car now. Both turbos ported. My question is which turbo would be better for me. I just purchased dsmlink and I want to be around 20 psi or more if my motor will hold it. My profile is up to date. Stock 7 bolt with 40-50k (JDM motor). Anyone with information will help a lot. I want to push this 7 bolt to the max. If it goes it goes! Gives me more reason to build my 6 bolt I have sitting in the garage.

 

[nightracer91]

I'd say go big!! Rock that 20G Bro!

 

[Boost92awd]

I want to push this 7 bolt to the max. If it goes it goes! Gives me more reason to build my 6 bolt I have sitting in the garage.

You answered your own question, use the 20G.

 

[DSMsOwnYourV8]

I've heard that that 18g will perform about the same as a 20g, but I would go with that Stealthy 20G and do some hustlin.

 

[spitefire1]

like they sad go big, and there's only one way to do it with a dsm! "go big or go home"

 

[deflator]

I hope you have upgraded headstuds otherwise you'll probably start pushing coolant long before the engine starts to go

 

[toofast82]

the 18g/6sl2 will probably outperform the 20g at 20psi due to larger turbine and the 18g compressor is just as efficient at this boost level. The 20g compressor wont outperform the 18g until a few more psi where the tdo5h turbine than cannot flow enough to keep up with the 20g, therefore making it a restriction. If you plan on running 25psi+, you may want to consider getting the turbine clipped on the 20g if thats the turbo you choose. They should be very close in power either way though.

 

[JusMX141]

I've heard that that 18g will perform about the same as a 20g, but I would go with that Stealthy 20G and do some hustlin.

Both turbos appear the same from the outside.

It's a tossup either way- the Bastard 20G most likely has a TD05H turbine, so the 20G has a bigger compressor but smaller turbine. The 18G has a larger TD06SL2 turbine capable of flowing at the 18G compressor's limit, but a slightly smaller compressor wheel than the Bastard 20G.

I'm more interested in what FP has to say about the shaft play. Definitely post back with their verdict.

 

[my1997gsx]

20g will make more power than a 18g. Lol
If your looking to push your motor you might even need a bigger turbo as long as you have the upgraded mods.

 

[toofast82]

20g will make more power than a 18g. Lol
If your looking to push your motor you might even need a bigger turbo as long as you have the upgraded mods.

Not necessarily, it really depends on how much boost he is planning on running and how efficient the compressor is. Plus the tdo5h turbine cannot flow enough for the 20g compressor at high boost levels(24psi+). Its not just a bigger, is better thing

 

[smokem]

Yeah please let us know what FP has to say when you hear from them as i just put on my 18g from them (350 mile now) and you kind of got me worried here. Hope it works out for you.

 

[JusMX141]

20g will make more power than a 18g.

I beg to differ.

Turbo requirement has to do with the potential of the entire package more than anything else. There are plenty of guys who bolt up big turbos and go slower.

If you eat a 5000-calorie daily diet, does that mean you'll have more energy than you would if you ate a 2000-calorie diet? No....it just means that you'll have the potential for more energy if your work day requires lots of physical activity. If you slam 5000 calories but only have the need for 2000, the rest is just waste and will eventually slow you down even more.

 

[->PrOjEcTGS<-]

I'd like to see FP come up with a "Bastard" 20g/6sl2. Now that's a turbo to be excited about!! Stock appearing + high flow potential.

 

[toofast82]

I'd like to see FP come up with a "Bastard" 20g/6sl2. Now that's a turbo to be excited about!! Stock appearing + high flow potential.

The tdo6sl2 turbine is actually smaller than a tdo6/6h turbine. Its just a little bigger than a tdo5h. So its not going to have the highest flow potential of turbines. They sell the turbo, but you'd have to get a tdo5h compressor cover machined to make it stock appearing.
Forced Performance Turbochargers: DSM 20G-6SL2 Street/Strip Turbocharger

 

[->PrOjEcTGS<-]

The tdo6sl2 turbine is actually smaller than a tdo6/6h turbine. Its just a little bigger than a tdo5h. So its not going to have the highest flow potential of turbines. They sell the turbo, but you'd have to get a tdo5h compressor cover machined to make it stock appearing.
Forced Performance Turbochargers: DSM 20G-6SL2 Street/Strip Turbocharger

Right... I just think the lag would be minimalized with the sl2 wheel as opposed to the 06/06h wheels. Also, I think the TDO5H 20g's would have a lot more potential with a larger turbine. Maybe that's something I should contact FP about.

I'm due for an upgrade from my S16G. It's getting boring. But, I want to keep the mitsu 16g style compressor cover.

 

[toofast82]

It will definitely spool a little quicker than the larger turbines. Im on the fence whether the 6sl2 turbine can flow enough for a 20g at very high boost levels like 27-30psi. I really don't think its large enough. It should be good up to about 25-26 if i had to guess. I lost my sheet with the exact specs but, I remember it being just a hair bigger than tdo5h turbine.

 

[->PrOjEcTGS<-]

I can say it's a great match on the 18g though. I've helped my buddy with his Talon net a 400hp dyno pull at 25psi on his 18g with a completely stock head and bottom end. We're currently building his engine with the hopes of drawing some more power out of it. The full 9 minus a port/polish.

 

[joyfil2001]

I have the same turbo so I am also interested about what FP says. It has slight shaft play now which I'm not to worried about.

Anyway, I think it is a toss up between the turbos. My buddy has a TD0520g and we are about dead even in power. My 18g definitely spools faster than his, but his pulls a little harder up top. If you are looking for more power then I would say to go with a TD06/20g. But I am very happy with my 18g - lots of power, no lag.

 

[delta448]

joyfil, do you both run the same cams, and is your buddy AWD?

 

[JusMX141]

I lost my sheet with the exact specs but, I remember it being just a hair bigger than tdo5h turbine.

It's actually just a hair smaller than a standard TD06 turbine, but the blade shape is completely different. The blades on the 6SL2 are straighter and don't cup as much as a standard TD06, so backpressure is reduced, flow is increased, and additional lag is barely noticeable.

The 6SL2 turbine is Mitsubishi's answer to Garrett's popular T31 turbine....they're almost identical in size and shape.

 

[joyfil2001]

joyfil, do you both run the same cams, and is your buddy AWD?

We are both running stock cams. He has an AWD 1g.

 

[delta448]

^Thanks.
These two are both around the size I'm looking at for my next turbo, although with a 20G compressor I'd not really favor the small turbine. I'd much rather go with the 18G or possibly a HX35. Price and availability determines a lot for me though.

 

[joyfil2001]

I would suggest the FP18g. Spools fast, has lots of power, and is cheaper.

 

[my1997gsx]

Not necessarily, it really depends on how much boost he is planning on running and how efficient the compressor is. Plus the tdo5h turbine cannot flow enough for the 20g compressor at high boost levels(24psi+). Its not just a bigger, is better thing

 

[91spoolin]

I actually went from a 16g to an 18g and have no complaints. Similiar spool up and better topend.