max boost from a 14b

[Smokin GST]

my car will be done this weekend... crankwalk recovery. here will be my setup (this is in a 97 GS-T):

2G MAS (duh)
MKIV supra intercooler
1G BOV (slightly crushed, no compressor surge!)
2G throttle body elbow
1G throttle body
1G intake manifold
1G head
6-bolt bottom end
2G exhaust manifold
14b turbo
2G O2 housing
stock 2G FWD Turbo exhaust (will be doing 2.5" cutout soon)

i am using the RRE j-pipe for the 14b install. none of the parts are ported. i ran 16psi on the T-25 just fine, no fuel cut problems or knock problems. but now i'm going to have a 14b (yay for JDM motors). i'm curious what the highest efficient boost level is on a 14b, and what is the highest SAFEST level to run. now realize that i don't constantly beat on my car... i drive like an old woman 90% of the time, but when i ring it out, i stand on the gas pedal for a while. i was thinking 18psi, but i don't know if that will be too hot (16psi was probably too much from the T-25). i plan to start at 15psi and work my way up, checking for knock along the way, and finding a boost level where i don't hit fuel cut. i'm just curious if anybody has a similar setup, and what kind of boost levels you are running. my fuel system is completely stock. need to get off my butt and rewire the fuel pump.

 

[Spidey]

I think you'll be pushing the 14b out of efficiency range at around 25psi, max you should be able to run without fuel upgrades will be around 17-18psi.

HTH,
Spidey

 

[RipperXX]

I would think on the stock fuel system he would start to run lean around 16psi... also I personaly think it would be runing out of steam sooner.. more like 18-20psi...

but then I have yet to start pumping up my new 14b so i duno but I will say this.. always better to ovre guess than under...

becouse on one side you just dont make as much power...on the other you get to watch your engine melt...

 

[Smokin GST]

Originally posted by RipperXX
becouse on one side you just dont make as much power...on the other you get to watch your engine melt...

, i like the way you put that.. yea, i don't want to see my new 6-bolt turn into a smoldering block of glowing red goo...

hopefully, i'll be making enough money this summer to recover from the motor swap bill and then get my hands on a 255lph fuel pump, FPR (since it'd be a high pressure pump), 550ccs, and a S-AFC. i'm wondering if i might get random misfire with the new motor, in which case i'll need a S-AFC anyway.

 

[blinded]

Originally posted by Smokin GST


i'm wondering if i might get random misfire with the new motor, in which case i'll need a S-AFC anyway.

You'd need dsmlink; afc won't help with that.

 

[Spidey]

You also won't need more than a 190 pump with the 14b, why waste the extra money on a 255 and an FPR? Rewire your stock pump, and you should see 17-18psi without a problem, keyword being "should," as it is done all the time.

 

[Vinnie]

If you have an upgraded fuel pump, you can run up to 22psi on the 14b with stock injectors, more than that and you will get fuel cut.

But I think the 14b starts creating to much heat over 19-20 psi, I could be wrong.

 

[Slow99x]

Why waste the money on a 190lph fuel pump when you could just get the 255 and not have to upgrade again later. Anyway, I could hold up to 22psi when I had a 14b but I did have a much larger intercooler than the one you mentioned and I did run 110 octane gas when I was at that boost level. You will hit fuel cut at anything over 15-16psi so save yourself the trouble and get the injectors and fuel pump right away. An EGT gauge other than Autometer will help too. At this point an AFC is a must.

 

[Smokin GST]

to get around random misfire, i'll use the potentiometer on the barometric pressure sensor signal... then an AFC to richen the mixture back up...

i want the 255 lph because eventually, i'll be getting a 16G. using the 14b just because it's better than a T-25, and came with my motor anyway. we'll find out how it all works out in a few days...

 

[paperboy]

i just put on my ported 14b a few days back. it is night and day diff. although fuel cut comes at about 18lbs in 2nd. if your running a 3in turbo back exhaust get ready for some port work to kill the creep. otherwise a pump and injectors are a must, next on my list too.

 

[Laser0385]

Mods:

rewired 190 Walbro
2g 02 housing
port work
intake
MBC
no exhaust
118 octane

I ran 25 psi on those mods, toasted my stock clutch in the process of running a 14.629 but I think the turbo kind of gave up after 20 psi, it just kept going without really making much power.

I would say that 17-19 psi is the key number for your application right now, as stated many times.

Jake

 

[Slow99x]

You can run more than 19 psi on a 14b but a good front mount intercooler will help. I ran against a 1g talon that has a ported 16g, HKS cams and a whole slew of other stuff and I destroyed him by about 5 cars when I was still running my 14b on my full weight 99 GSX. The one thing that I had and he didn't is a front mount and I was running race gas and he was on 93 octane. The point is that you can run 22psi but make sure you can cool it down and supply the engine with enough of the right fuel.

 

[Smokin GST]

my supra IC is pretty big, 496ci. not a front mount by any means, but it's still got some capacity. shit... supras are doing 11s on their stock sidemount... granted they have more displacement but ya know...

we'll see how it runs. i'm going to install a knock LED when i get my car back so i can see what's goin on.

 

[kpt4321]

The knock LED is close to useless, you need a logger.


....Kyle T.