S5 wastegate is bigger and that helps keep boost down- BUT, I have also heard the S5 AR is higher (S4 .8, S5 1.0) and that also helps keep boost down, as well as being less of a restriction at higher rpms. You also don't have to worry about actuating/modifying the dual scroll actuator/flapper w/ S5 as it has none.
Besides porting the wastegate, I would restrict the intake to keep the boost down. I prefer restricted intake over restricted exhaust as far as how turbo response "feels."

 

Yes- I was thinking of an intake restrictor....
I'll see how the boost goes- it would be nice to see 8 psi steady from 1500 rpms up to redline!

Another thought- I can also hook up boost sensitive H2O injection... Inject a high pressure water mist whenever boost goes over 8 psi... I could then run up to 13-14 psi, let the stock turbo max out!
I must look into this....

 

i dont know what i hit now because someone hit my car and it is totaled...and its all apart...i just got the s5 turbo and manifold...hasnt been bolted up yet...

 

I hit 13 PSI in 4th with racing beat turbo back 3" , bonez intake, walbro fuel pump right now I am running 13.4 at 105 in the 1/4 mile.

 

yo twista what mods you have? and which TII?

ok i read your profile and see that its a 91TII but what mods you have? what you listed before is all you have. im just curious to see what mine can do.

 

I'm keeping the exhaust to 2 1/2"...
I think 13psi would be seriously detonating.....even with proper fuel and timing...
Or am I wrong?

 

Hey- at what boost would it be considered a nessecity to get a stronger fuel pump?? I was assuming the stock one would be fine up to 10 psi- correct? Oh- and the 550CC injectors too?

Also- I am assuming I'm going to be kissing the 9000rpm goodbye...
Oh well.

 

Detonation happens because you don't have proper fuel and timing.
If you supply enough quality fuel and run the right ingition settings you can run as much boost as you want without detonation. Until stuff starts breaking that is!

 

Ya- but with the high comp rotors, I am going to have to really retard the timing, and dump in buckets of fuel.

I am more likely to detonate at a 12:1 mixture at 7000 rpm's than a stock low comp TII would- correct?
If you think my engine would be fine given normal, common sense mixtures, then damn... I'm letting it give full boost!

 

I can hit 12 psi in 2nd and 15 psi in 3rd and 4th. Kinda scared the **** out of me when it happened. The weld on the flange at the end of the stock DP broke off so there is about 1.5" - 2" space between the dp and stock straight pipe and the straight pipe is about 1" lower because the hangers broke. I got my rb dp and presilencer going in on friday. Let's see how much my boost pressure drops by.

 

Not really, well.. kinda.. the turbo isn't made to be efficient at those pressures, and it'll probably make a TON of heat compared to a turbo that's made to boost to those levels. Detonation time.

 

I have ran 21 psi with no problems.

 

stock N/A one? no way. it's smaller then the tII one. and 10psi on your motor will be more power then 10 on a TII. so I'd say the Tii one is too small too. get a walbro

if you are going to be running 10psi I'd allmost say that 550's are too small too.

 

basicly yes. but it'll also take longer to get there where as a boost controler set to 12psi would reach it alot sooner.

 

Check your boost gauge - I think it's smoking crack...


-Ted