Asleep

Nice way to put it.

And at higher boost is will be less of an issue I am saying.

BDC I respect for his knowledge. Can we get Brian in here to answer why so low (12psi). My presumption is that he told you this for reasons that might be getting left out...I think it was a temporary thing until something else gets resolved. A HB at 12psi is like driving around on the verge of orgasm, with no "happy ending."

I'm glad Carl chimed in with his experience...so we know that the manifold, coupled with a certain size WG works well. Carl, he tried just on WG spring alone and got the spike. WIth no EBC attached.

Tony

pp13bnos

iTrader: (1)

This is just my opinion, but I think that Tony is pretty much right. I'm running a XS cast manifold with a 50mm HKS unit. I have a 10psi spring, and without my silencers in my n1 dual, I'll see 13+psi. It use to be 11-12 psi before I installed a 3.5" DP/MP. If the exaust is to free flow, and manifold runners are'nt placed correctly, you will see more boost than your spring. CJ

fdracer

yup, basically a "if can't beat 'em join 'em" situation. that's what i would do, just tune for higher boost, might as well make lemonade outta your lemons.

Crusader_9x

I would love to tune for higher boost but was told I couldnt. Besides Im not sure how well that would work anyway, the creep changes greatly with the temperature outside. When its like 70 or above outside i get very little creep, however the colder it gets the more it creeps.

BDC

Hey guys,

At Riley's request I'm jumping in here. When I was out in TN doing the tuning on his car, we ran into this boost creep problem. At the time, I didn't feel comfortable doing high-end stuff to the point where the boost pressure could conceivably rocket to the moon.

As far as the 13psi thing is concerned, it needs to be thoroughly understood in the community that "boost pressure" is a very ambiguous term at best and can't be used as a standard for measuring anything, especially potential power output. For example, there is nothing magical about "15psi" as it seems to be commonly misunderstood in the community. Too many things interfere with this: Air temperature, barometric pressure, compressor size, turbine size, engine volumetric efficiency @ x RPM, etc. Riley's engine has one of my what I call "Spec-X" half-bridgeports which are a bit more on a raunchy, aggressive size, close to a J-Port. The BP cuts are quite tall and wide, much wider than I normally do, therefore they induce a great deal of overlap into the motor as well as considerably raise its VE.

Arguably, the same "boost" pressure on Riley's motor has the potential, especially at higher RPM's, to produce a considerable amount more power than compared to a stock or street port w/ substantial less overlap. In all practical sense, this is what I've seen over and over again when comparing the two.

With that said, when it comes to more power, there's more load, which also lends towards more heat. The big limiter here on Riley's motor, as it is on just about everybody else's out there in the community, is the type of fuel used: Pump gas. It has its limits, and since Riley's engine is potentially a good deal more efficient than your garden variety 13B turbo motor, its potential heat output is also higher, which is the single most significant factor when it comes to challenging the octane rating of a fuel used. In this case, pump gas is the suspect, and since it has a volatile temper, I'd rather keep things on the conservative side given its ability to blow up in your face when you least expect it.

Another note -- Since I was out of town and doing this as a professional job, there's liability concerns that have to be taken info effect when it comes to messing with someone else's car. That also has a portion to play in this.

B

dubulup

save $200 and piece together a 100psi WI system and run with it!!! there has to be a boost pressure the WG feels comfortable controlling.

watch A:F
watch EGT
watch Fuel pressure
watch Duty Cycle
watch AIT (make sure you don't ingest air warmer than your coolant EEK!)

Carl Byck

Run some 110 octane, and 11.5 plugs, you'll be safe, and you can see what it does at ~13-14 psi, if it's stable, you can tune for that boost. Brian will his current tune allow that? I do not undestand why anyone runs plugs hotter than a 10 on a modded car, it's just asking for trouble IMHO. I also think that the .96 is a problem, that hotside with a 4" DP is a big power set-up, you will see that if you make a pull from 4000 rpm, as opposed to 2500 it will boost a couple psi lower on the top end. I would downsize the hotside to a .81(I'm a little predisposed to that one)you can also go to a lighter spring, it will open early without an ebc, but with one, it may work nicely. My friend and I did this with his GT42R supra, and we can keep the boost down to 8 psi with a ~6lb spring and the AVCR. Put race gas in the tank, and play with it after confiring with BDC, alternately add WI, and be done with it(my first choice. However, I would go with an aquamist, or other high quality unit to protect your investment. Good luck, Carl

twokrx7

iTrader: (1)

I side with Carl, put some race gas in and experiment with the boost control.

I had creep with that cast log mani when using the smaller HKS wg, creep was gone with the larger HKS wg. Motor was a SP tho, not a HBP. I did find that my HKS wg leaked once open and would bleed off the pressure in the boost reference line (verified by much testing), so I used a large diameter line from my Greddy elbow location to feed plently of boost to the wg actuator.

Crusader_9x

I have a duel stage water injection setup that is injecting about 20% water. Although it is just a on off kinda thing. I am wanting to get some of those aquamist hsv so i can mirror the injectors. That way i get better water setup instead of on and off.

I have 9s in the leading and 10.5s in the trailing. When BDC was tuning the car he said the 10.5 plugs were overkill but i keep them anyway.

APEXL8T

For what it worth I am having the same problems...
TO4R to a 3.5 DP and 3.5 pipe out. The waste gate elbow doesnt flow from the HKS cast very well. Unlike other manifolds that have two into one runners the HKS cast is out of the back side alone.
I have a 10 lbs spring dumping to atmos. with a boost line hooked from the turbo out let staight to the WG. We even opened (ported) the bowl to open it up a little.
THE HKS log doesnt except the new style WG. I just bought the HKS 50 and it will not match($ 600.00 +). now everything from the IC piping , include oil lines and the custom StainlessSteel exhaust has to be re fabricated for a new manifold.
C.BYCK may get away with the mid to high boost because he also has a smaller more restrictive .81 to my 1.00 turbine.
We have checked for leaks and dissassemble everything.
I wish others the best and do not recomend the cast manifold for larger applications.
L8T

andre sinclair

iTrader: (36)

Carl,
Andre here! how are you? I`m having some problems with boost creep and would like to pick your brain.

I`ve a HKS cast manifold and a E-Bay 50mm WG, T66 A/R .70 P-trim, 3" DP and exhaust. My boost controller is eliminated as I`ve run a vacuum line from the turbo compressor to the side of the wastegate. I have also installed a HKS authentic 10 psi yellow spring in the WG, but when i drive in 3rd gear the boost will stay at 12 psi then as i shift gears in 4th it will creep to 15/18 psi.

Can you help me with this problem?

thanks,

Andre