Jump to content
SAU Community

Recommended Posts

I've just recently purchased a Blitz i-Colour Spec-R boost controller. I have gone through the installation manual and I'm still a bit confused on how to Install it.

I have a twin turbo set up gt2860r -5.

Now my question is- Would I need to tap in a fitting for the hoses on the compressor hosing on both turbos?

There is a diagram In the manual. The solanoid Unit has a Out/In. (Out) T's off and goes to the valve on both actuators and (In) Looks like its T's off into both compressor housings.

Instead of taking off the turbos and tapping in fittings for the (In) is there another way?

Thanks.

Link to comment
https://www.sau.com.au/forums/topic/443426-dual-solanoid-for-gtr/
Share on other sites

You should take the boost signal to the gauge from the inlet manifold.

The line to the waste gates via the solenoid should be done as GTSBoy has said.

As per the diagram the blue line is the pressure source that should go to the new solenoid then waste gates.

Edited by Ben C34

The boost source is the green pipe labeled>

"To bottom of collector, boost source"

The blue pipe simply connects to the induction pipework ahead of the turbo inlets.

Good point . The blue is the return for the bled air back to the engine for emissions requirements. Can't vent anything to the atmosphere!

Note that the first part of this discussion uses the word "plenum" in the sense of the plenum on most cars, not the GTR. The multiple throttles are a complication. So in the above posts the term "inlet manifold" was used. I take that to mean "after the throttles" in the GTR. In any other RB the plenum is after the throttles.

For the purposes of driving a wastegate you want to measure the boost pressure upstream the throttle. If you measure it downstream the throttle then with a partially closed throttle you may have a situation where the pressure in the plenum is much lower than the target boost level but the pressure upstream the throttle is higher. This situation cannot continue indefinitely, but it can exist. At this time the EBC would be trying to close the wastegate to raise the boost (because it's measuring low) but in reality the turbo is pumping more pressure. Because the pressure at the turbo outlet is high but the flow is low (part closed throttle) then you may approach the surge line on the compressor map.

What you actually want is for the EBC to try to maintain the boost that the turbo is making at or less than the max boost you want, rather than allowing the turbo to spin away, effectively uncontrolled.

Now, I acknowledge that a partially closed throttle means that the power output of the engine is under the control of the driver and he is clearly asking for less than max power. It also means that the flow of exhaust gases is being modulated and is therefore less than you would have at WOT. But I think we can all appreciate that under these circumstances you would need a larger proportion of the exhaust flow to go out via the wastegate than the turbine. If the EBC is trying to raise the boost level in the plenum though, then the wastegate will be more closed than needed, meaning more flow through the turbine, meaning more compressor speed. So even with the concept of the driver's ankle being in control, there is a strong possibility of overdriving the turbo relative to what it needs. So we get back to the possibility of surge.

Whether the problem occurs or not may well come down to relative sizing of wastegate to turbine and matching of the exhaust side to the compressor side, which is a lot of variables to play with.

It's all avoided by hooking up the boost signal for the EBC from the turbo outlets.

In a GTR, the plenum is functionally equivalent to the turbo outlet relative to the throttle location, so long as the original throttles are still in use. Single TB conversions are the same as any other RB.

If, in the GTR, the original boost control solenoid is hooked up to the plenum, then that's fine. If it's hooked up to the inlet manifold (which would be the vacuum balance tube underneath) then that opens it all up to the problem I describe above.

Yup, if that connection is to the plenum itself.

In this case though, whilst it will be easier to do that (on the assumption that the standard location is there and available) you'd get better boost control response by keeping all the lines on one side of the engine. Shorter pipes means less pneumatic delay. The original GTR boost control system had to have one pipe go all the way around the engine. But in RB25s and so on, the boost control solenoid was right next to the turbo, for good reason.

FWIW though, the difference won't be terrible and would still work fine.

Instead of tapping fittings on the turbo compressor housing and going through all the trouble of taking out the turbos. I think I might just end up tapping fittings on both of the pipes that leads out from the housing Where all the decompression charge happens. Less parts to take off and easier. Thanks for your inputs.

I recent bought a Greddy Profec Boost Controller and was getting confussed on how to set it up because greddy instructions say to go off the fuel pressure regulator for a signal for the sensor unit. But reading different threads and watching Mighty Car Mods it seems to be a bad practice as you don't want to wreck this signal.

Below I have added my setup which im thinking of doing to my r33 gtr, Just wondering if it would work?

post-120471-0-34691200-1400673227_thumb.jpg

Greddy Setup

post-120471-0-85269500-1400673606_thumb.jpg

Thanks for your input and thanks Fat32gtr and everyone that has put input into this thread so far.

Do not confuse the boost source used for control with the boost source used for display.

The Profec, like most EBCs, is not a closed loop controller. If you look at the installation instructions carefully you will see that the boost signal line they recommend you connect to the FPR signal line is not involved in control at all. it is only the signal that goes to the MAP sensor in the Profec head unit, used for display of boost in the manifold. The actual control boost signal is drawn from the turbo outlet, as shown in their diagram, and the same as instructions given above.

There is very good reason for not tee-ing into the FPR signal line. if nothing goes wrong, then there is no problem. But if you tee in a nice long boost signal hose and it melts or splits or whatever, then you will have a nasty leak in the FPR sense line and your mixtures could go nastily out of control (ie, lean). Not desirable. I think Greddy only recommend that you tee the Profec MAP signal line into there because it is one place that the know will be available on every car that the Profec might get installed into. Saves having to describe a whole bunch of different possibilities for manifold tapping locations.

So for the sensor unit signal to supply the control unit can I tee into the factory boost line that supply the gauges inside the car.

And then in my drawing above not tee into the boost source line which go's from the solenoid to the plenum?

Um....yeah. The GTR is complicated. If you hook the sensor up to the plenum you will never read vacuum, because the vacuum is all on the other side of the throttles. So tee the sensor into the other existing boost gauge lines and you will have a true manifold pressure signal.

And the actuator control signal can come from the plenum but would be better coming from closer to the turbo outlets. Your choice.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I'm looking for some real world experiences/feed back from anyone who has personally ran a EFR7670 with a 1.05 exhaust housing or a .83 I'm leaning towards the .83 because its a street car used mostly for spirited driving in the canyons roads. I"m not looking for big numbers on paper. I want a responsive powerband that will be very linear to 8000 rpm. I dont mind if power remains somewhat flat but dont want power to drop off on top. The turbo I've purchased is a 1.05, although the mounting flange T3 vs T4 and internal vs external waste gates are different on both housings, I not concern about swapping parts or making fabrication mods to get what I want. Based on some of the research I've done with chat gpt, the 1.05 housing seems to be the way to go with slightly more lag and future proofing for more mods but recommends .83 for best response/street car setup. AI doesn't have the same emotions as real people driving a GTR so I think you guys will be able to give me better feed back 😀   
    • Surely somebody has one in VIC. Have you asked at any shops?  Is this the yearly inspection or did you get a canary?
    • This is where I share pain with you, @Duncan. The move to change so many cooling system pieces to plastic is a killer! Plastic end tanks and a few plastic hose flanges on my car's fail after so little time.  Curious about the need for a bigger rad, is that just for long sessions in the summer or because the car generally needs more cooling?
    • So, that is it! It is a pretty expensive process with the ATF costing 50-100 per 5 litres, and a mechanic will probably charge plenty because they don't want to do it. Still, considering how dirty my fluid was at 120,000klm I think it would be worth doing more like every 80,000 to keep the trans happy, they are very expensive to replace. The job is not that hard if you have the specialist tools so you can save a bit of money and do it yourself!
    • OK, onto filling. So I don't really have any pics, but will describe the process as best I can. The USDM workshop manual also covers it from TM-285 onwards. First, make sure the drain plug (17mm) is snug. Not too tight yet because it is coming off again. Note it does have a copper washer that you could replace or anneal (heat up with a blow torch) to seal nicely. Remove the fill plug, which has an inhex (I think it was 6mm but didn't check). Then, screw in the fill fitting, making sure it has a suitable o-ring (mine came without but I think it is meant to be supplied). It is important that you only screw it in hand tight. I didn't get a good pic of it, but the fill plug leads to a tube about 70mm long inside the transmission. This sets the factory level for fluid in the trans (above the join line for the pan!) and will take about 3l to fill. You then need to connect your fluid pump to the fitting via a hose, and pump in whatever amount of fluid you removed (maybe 3 litres, in my case 7 litres). If you put in more than 3l, it will spill out when you remove the fitting, so do quickly and with a drain pan underneath. Once you have pumped in the required amount of clean ATF, you start the engine and run it for 3 minutes to let the fluid circulate. Don't run it longer and if possible check the fluid temp is under 40oC (Ecutek shows Auto Trans Fluid temp now, or you could use an infrared temp gun on the bottom of the pan). The manual stresses the bit about fluid temperature because it expands when hot an might result in an underfil. So from here, the factory manual says to do the "spill and fill" again, and I did. That is, put an oil pan under the drain plug and undo it with a 17mm spanner, then watch your expensive fluid fall back out again, you should get about 3 litres.  Then, put the drain plug back in, pump 3 litres back in through the fill plug with the fitting and pump, disconnect the fill fitting and replace the fill plug, start the car and run for another 3 minutes (making sure the temp is still under 40oC). The manual then asks for a 3rd "spill and fill" just like above. I also did that and so had put 13l in by now.  This time they want you to keep the engine running and run the transmission through R and D (I hope the wheels are still off the ground!) for a while, and allow the trans temp to get to 40oC, then engine off. Finally, back under the car and undo the fill plug to let the overfill drain out; it will stop running when fluid is at the top of the levelling tube. According to the factory, that is job done! Post that, I reconnected the fill fitting and pumped in an extra 0.5l. AMS says 1.5l overfill is safe, but I started with less to see how it goes, I will add another 1.0 litres later if I'm still not happy with the hot shifts.
×
×
  • Create New...