SR20 Forum banner

1 - 20 of 24 Posts

·
SE-R Bastard
Joined
·
938 Posts
Discussion Starter · #1 ·
Thinking of bolting on a system to my DE.

Question.
I was told max boost on a DE should be about 10 psi. Is this correct?

If I run 10 psi on a t-25 should be good for 220 whp is this correct?

What about a t-28? Max boost and HP?

Would 10 psi on a t-28 be efficient? Doesn't really seem like it would be in the sweet spot.

I'm just trying to figure out if it's woth it to piece to hether a bolt on system or not. I'd like to run low 13's in the 1/4.
 

·
Registered
Joined
·
263 Posts
t-25: 12 PSI
t-28: around 15 psi
Larger turbo: 22psi

Others may tell you to boost higher on the smaller turbos, but there is no doubt that you are sacrificing turbo and engine life for little gain.
 

·
SE-R Bastard
Joined
·
938 Posts
Discussion Starter · #3 ·
I was told it's not safe over 10 psi because of the 9:5:1 compression. Please explain.
 

·
SE-R Bastard
Joined
·
938 Posts
Discussion Starter · #4 ·
ttt
 

·
SE-R Bastard
Joined
·
938 Posts
Discussion Starter · #6 ·
nsracer said:
Repeat after me... C16 is your friend :D
I have no clue what that means. :confused:
 

·
El Chingon
Joined
·
892 Posts
C16 is leaded race fuel. I've seen 20+ psi on a stock bottom end SR20 running this fuel. Frank O. put down some pretty nice numbers running C16 and 22 psi on a stock bottom end! It raises the threshold of detonation considerably! Water injection has a similar effect.
 

·
SE-R Bastard
Joined
·
938 Posts
Discussion Starter · #8 ·
Ok let me rephrase. This will be a pump gas setup. (93 octane) Now what kind of #'s are we talking? It there a FAQ on this?
 

·
El Chingon
Joined
·
892 Posts
On pump gas I run 12 psi daily with no problems. And this is in hot as hell AZ. That's as far as I'll take it without growing some bigger [email protected] :D If you're running water injection, I've heard of ~18 psi on pump gas (you might wanna verify that with either Jay H. or someone that's running water).
 

·
SE-R Bastard
Joined
·
938 Posts
Discussion Starter · #10 ·
Is this with a t-25? Top mount IC? I know a T-25 & T-28 @ 12 psi would have a very different flow. Just wanna know what is safe for each application. This is pump gas only with no water injection and probably a stock Top mount IC.

Any turbo GuRu's?
 

·
El Chingon
Joined
·
892 Posts
T25s suck man. If you're gonna bolt something on to your car, you might as well go with a bigger turbo. Also, I would never run the top mount IC. Just think of it this way.. if you don't have money to do it right right now, save up some money and do it right once! Don't take shortcuts that *can* eventually give you big headaches and end up costing you more in the end. Now, if you're set on running a small turbo (such as the T25 or T28), at least do a FMIC and don't push it extremely hard (T25 likes ~10 psi. but anything above ~14 and effeciency drops like a mother; T28 likes a bit more (~13-14) and can go pretty high (~18) but again, since it's a small turbo, efficiency suffers). I'd run the T28 if you can find one. Now, you are right: 12 psi = 12 psi, but the flow between the turbos (cfm) will be different. Obviously the T28 will be a tad more efficient. If you want a kick-ass turbo that is small and will give good numbers, look for a T-28 from the GTi-R and get the compressor housing from an S14 Sylvia (T-04B housing) and bolt that puppy up! You'll be looking at some decent numbers with the ability to push some good boost and spool up by about 3.5K RPMs. That turbo should be good for 280+ whp and that should definitely get you in the 13s. Dump in some C16 at the track :D, crank up the boost, and low 13s shouldn't really be a problem.
 

·
rollin 4 deep with JoeD
Joined
·
1,410 Posts
nsracer said:
On pump gas I run 12 psi daily with no problems. And this is in hot as hell AZ. That's as far as I'll take it without growing some bigger [email protected] :D
David, are you on the stock bottom end still? I can't remember:confused: , if you can, post the specs of your turbo kit again. I don't ever go pat 10-10.5 psi with 91 octane, even when its nice and chilly out here in So. Cali. I thought with the 9.5:1 compression, and the massive flow of the t3/t04e at 10 psi, that was about max. I once tried 12 psi on pump gas, but I heard some nasty noises from my motor and let off, thinking it was detonation. Maybe it was just misfire though, since my plugs were at their stock gap. IT sounded like it was missing, or just rough combustion.

****, now you've got me wondering. I'm out the door to school, and I think I'll try for 12 psi :D haha, **** it!:cool:

Frank
96 200sx SE-R
F-MAX stage 2
Stock motor!
 

·
SE-R Bastard
Joined
·
938 Posts
Discussion Starter · #13 ·
Thanks for the input. Looks like i'll be doing the GTi-R manifold & Turbo.

-Kris
 

·
Hi Officer, how ya doin'?
Joined
·
438 Posts
I've had my EVC set at 1.3 bar (20psi) once with pump gas. I'll NEVER do it again, but the engine survived (raced and beat a supercharger '96 Mustang Cobra).
I usually run 14psi on the street with 93 octane. No detonation problems what-so-ever. I run .022" gap on my plugs, fuel set at 45psi, 15 degrees timing. I don't recommend this to everyone else, but I've had great success with my combination. I don't want to be the cause of guys blowing their motors. ;)
 

·
rollin 4 deep with JoeD
Joined
·
1,410 Posts
Big Boost said:
I've had my EVC set at 1.3 bar (20psi) once with pump gas. I'll NEVER do it again, but the engine survived (raced and beat a supercharger '96 Mustang Cobra).
I usually run 14psi on the street with 93 octane. No detonation problems what-so-ever. I run .022" gap on my plugs, fuel set at 45psi, 15 degrees timing. I don't recommend this to everyone else, but I've had great success with my combination. I don't want to be the cause of guys blowing their motors. ;)
Is this with the factory stock bottom end? 9.5:1 compression?

Frank
 

·
Hi Officer, how ya doin'?
Joined
·
438 Posts
Yep.........

It's a bone stock motor with no internal work, just external stuff like the intake manifold, MSD 6AL, blaster 3 coil and 255lph intank fuel pump. I installed it last Spring to replace my wannabe DE(T). If I use 108 Octane additive, I've took it up to 1.1 bar (16psi). I'm one crazy Mo'Fo, so (again) don't follow my lead...unless you're brave or crazy like me.
 

·
El Chingon
Joined
·
892 Posts
Yea Frank, I'm still on the stock bottom-end. I turboed the car in July and have been running on 12 psi since then. I have pretty much the same set-up as you do (you're running the 4 bar fuel program, right) except that I'm running on the smaller (.63 a/r) T3/T04E. Now, keep in mind that I drive like an old lady and the only time that the car sees 12 psi is when 1) I run into stupid ****ers on the freeway 2) I'm showing off to the girls ;) 3) I'm falling asleep and wanna wake up by scaring the **** out of myself (I'm running an open wastegate :D). So, I don't really abuse the car that much (except at the track). I've never noticed detonation (never heard it detonating and haven't seen it on the plugs) so thats why I feel safe pushing it the way I do. But, I don't have balls as big as Rob's (I haven't even pushed it to past 17 psi even when I'm on C16!). 20 psi on pump gas takes some big cajones! One day, though :D
 

·
rollin 4 deep with JoeD
Joined
·
1,410 Posts
You guys are nuts! When I first installed my kit I went out for a short blast, floored it, and hit 24 psi of boost! OOPS! I had my Profec B hooked up ass backwards and the wategate never opened. No harm done, just TONS of wheel spin in second.

I was talking to Kojima one night about trying for 12-14 psi on pump gas once, and he said maybe on a cold night I could do a quick blast, but then chill for a little bit because the intercooler would probably get heatsoaked. So next time a Z28 or Cobra wants to race I'll probably try for that insane 14 psi for one quick run :)

BTW, what do you guys do about insane wheel spin at this level? What tires are you all running?

Frank
1996 200sx SE-R
F-MAX Stage 2
 

·
El Chingon
Joined
·
892 Posts
24 psi! Ouch! My car's never seen anything past 17!

Do you have an EGT gauge? I have that and an autometer water temp gauge (stock sucks) and if I'm on it, I just make sure I keep those two temps at an acceptable level. If anything seems higher than normal or even slightly out of wack, I get out of it right away. That, and the fact that my car runs super rich keep me feeling okay about the boost I push. BTW, I don't think you'll need 14 psi for Z28s or Cobras... ;)

As far a tires go, I'm running the Kumhos on 17" wheels. I was rolling around on the stockers wrapped with Kumhos and traction sucked at any boost level! I even got the ****er to do a rolling burnout in 3rd on the freeway with the stocks!! With the 17s it's a bit better, but still sucks with anything above 11 psi (which is what my wastegate spring is at). That's why I don't get on it much on the street (tires can get expensive!).
 

·
Hi Officer, how ya doin'?
Joined
·
438 Posts
I go for the sleeper look. I have my stock wheels but I have 205/55/15 Nitto 555R Drag radials. First gear for me is pointless unless I have slicks on. Second gear gets hairy as the tires break loose on the top of second and the start of third. As far as the amount of boost needed to whoop some ass, 9-10 psi should be enough with the 50lb program. Not sure about 370cc injectors.
 
1 - 20 of 24 Posts
Top