soru81

I've never heard of or seen before on this forum, that someone ever had boost creep after the wg has been ported, on stock twins running sequentially. So I'd like to contribute to the forum and let everyone know, that it obviously can happen. It happened to me. I have new 99 twins with ported WG (stock flapper), m2 intake, and really nice full 3inch exhaust. I have right (large enough) hose routed without any restrictions from the turbo housing to the WG actuator, and the other nipple capped. This way I assure that WG valve is opened earliest. I still get around 9psi on primary turbo, and 12psi and creeping above (I don't push it) on the second turbo at 5000+ rpms...

Anyone has any idea what can I do? If no better solution, I will have to install the restrictor in exhaust. Altough I hate just to think of it...

Herblenny

iTrader: (13)

Are you running PFC?? if not what ECU?
If you are running PFC, it could be your boost setting and injector duty.

soru81

Pettit Unlimited ECU. I don't understand how could injector duty cycle have any influence on boost?

alberto_mg

how about getting a boost controller like the profec?

soru81

I have profec, but it doesn't make any sense to install it. It can only maintan same boost or even worse. The WG is obviously overwhelmed when it's fully open, profec can only help making higher boost...

I was thinking about lengthening the WCA rod... I don't know if it's even possible or if it would make any success...

Enconsiderate

there maybe something wrong with your actuator.

littlemilla3

iTrader: (1)

A boost controller isn't going to help. If he has a hose routed right from the compressor housing to the wastegate actuator, that's the best way to set it up for the lowest boost possible.

The wastegate is opening, but it obviously can't bypass enough exhaust gas to lower the turbine speed enough to lower the boost the turbos are creating. Who ported your wastegate? I think it isn't ported enough or the '99 turbos are just way more efficient than the '93 units.

I have stock non-sequential turbos with full intake/exhaust and got a rock solid 7 psi with the actuator set up as you have it. I ported the wastegate myself as much as possible, without making the hole bigger than the door.

If I were you, I'd put in a restricter plate of some sort and see if that fixes the problem, but I see no problem in running 12 psi all the time, you have the supporting mods for it...

soru81

I saw the WG ported myself, before we assembled the turbo system. The hole was optimally ported, as much as possible - so that the door flapper still covers the hole. Maybe it the port after the hole should be ported - I think it wasn't, just the intial hole. But as far as I remember, that hole was the bottleneck and I don't think porting the tunnel would be the greatest restriction in there...

I don't think that 99 design adds so much, maybe a little. Or it's just because they're new and therefore more effecient. Also exhaust is from a local racing manufacturer, 3 inch from turbos to rear muffler which is more like 3 inch tube... anyway, I think exhaust doesn't represent any noticeable restriction in the gas flow. And, the weather here is also 10-15C right now, which is not really warm.

I would run it at 12psi, but I think it will creep even farther than that... And that reminds of something I need to ask. If I raise the boost (from the primary on), will I get less boost creep? Or more? For example, I get 13psi with no restriction in the line, 9psi on primary, 12 and creeping to 13 on secondary. Can I expect more solid 12psi, if I set the boost controller to appr.12psi? Or will I get the same creep to 13psi or maybe even higher?


OK, one question

JaNusSolSumnus

I think it has to do with the turbos being new and 99+ editions... I doubt the actuator is bad otherwise it wouldnt bleed off anything at all.

This has me concerned about my setup... I have an RX7.com ECU comming for 14.7psi and support for all my mods, including the 3" exhaust... so this should mean I dont have to worry about boost creep anymore? It's very unclear, I mean everyone says, no worries with a PFC only, but then there is the group who have the 'unlimited' remaps that say boost creep/spiking isnt a problem with it either as it is designed for the level of boost it would 'creep/spike' to anyways.

GL, let us know the solution as I'm sure you arent gonna be alone on this one.
~Kris

DaleClark

iTrader: (55)

Do the '99 twins have the restrictor pills built into the actuator nipples? The pills definitely give you some more boost and increase spoolup time.

Also, I don't know if the actuators on the '99 turbos have different spring rates. Might be worth getting out the Mityvac and finding out at what pressures will the actuators move. They may be more agressive than the '93-95 setup.

Dale

soru81

FYI, the wg control and turbo precontrol actuators are new, they come with new 99 twins...

1234rotor

iTrader: (1)

Drill out the restrictor hole in the turbo nipple. You could always then just run an inline (in-hose) restrictor pill if that didn't fix it.

I would be running the boost controller that you have though. Why just let it sit there??

cruiser

How do you know your wastegate opens at all ? What is your transition like ?

I have a restrictor plate and you could try with that and see if you indeed have too much flow.

alberto_mg

It seems weird. Doesn't sleepr1 use the 99spec turbos with a midpipe and run 12psi consistent.

I think something else might be wrong - like in the vac lines or maybe a small leak. Or maybe its the way you ran the vac lines for the Profec.

ptrhahn

iTrader: (9)

I use the '99's w/ no creep... ported motor, full exhaust... no boost control except for the PFC.

FWIW, they don't use pills and you shouldn't have to port the wastegate either (i didn't).

soru81

Sorry, but I have forgot to mention, both nipples were drilled out. Profec is not yet installed. I have the hose (stock length, I use to have something longer prepared for profec but have replaced it) from turbo housing routed to WCA. The other nipple on WCA is capped off. I can assure that this route is without any leaks, silicon hoses + tight tie wraps.
The hose from the turbo housing to the TPA (precontrol) is also stock length, but has old pills inside. Other nipple from TPA has hose to the stock and working precontrol solenoid.

Actuator is new, so I doubt it is not working. Mityvac is on it's way, so I will be able to check this for certain. I don't know for sure about the spring rate, but my guess would be it's the same 7psi spring inside... Otherwise, I also have old actuator I could test....

I also I doing on fabricating some different size restrictors and hopefully I will be able to test it soon.

Transition has a big dip to about 3psi. My CRV starts leaking at 3psi (test with pressure). Then it builds up very fast (500rpms) to 12psi and above and I let off the throttle.

Maybe I could run solid 12psi if configured on all powerband. Now I have 9psi or less on primary and then 12+ on twin mode... Anyway, can someone answer me this: