:(I know this is totally premature and probably unwarranted but you never know where life will take you and the decisions you will make in the future.. So here it goes....

 

If when you finish (or not) your project or perhaps you tire of it and is looking for something new, may I have first dibs on this ride? For the record.....this same question is how I acquired my SVX and XT6. I actually was eyeing my SVX for a couple of years.....waiting.

 

I think THIS Rx is something............well...nevermind. Just keep this in mind if/when you decide to sell it. Thank you sir...and happy modding.

 

OH..and that rebuild was 5 years ago. Be careful! Check, check, check and be sure things are COOL! I miss my RX!

Edited September 4, 200916 yr by Myxalplyx

first stop for this car is right back in the hands of one of the builders. He will give it a thorough check and we'll go from there. I will keep you in mind if I decide to move on. On the rebuild date MY Mistake I didn't check the date on the event and was told they built the car two weeks prior to the event.....the 2004 event was Sept 2003 so OOPS.

I just scored a sweet SVO intercooler that should help this engine make more power reliably. now to hunt down an oil cooler...

Edited September 9, 200916 yr by vagen

where are you racing at? I see you are in Charlotte, I live in York.

 

Sorry for hijacking the thread

go to ccrscca.com the auto cross schedule will be on that site. I hope to see you out there.

I'm going to keep my eye on this thread. I think I'm probably going to do most of the same to my own GL-10 wagon.

me too OH wait its my thread LOL!!!

 

I will start the modifications monday or tuesday and hopefully it will be ready for the state autocross championship on Oct 11.

I have decided rather than have a bleed valve boost control or a spring valve type I will build a simple electronic valve control. The parts list is short but it will work.

 

parts:

 

Adjustable N/O Hobbs switch

12v solenoid valve with 1/4 npt fittings

1/8 check valve

1/4 npt to 1/8 hose adapters = 3

1/8 tee fitting = 3

1/8 pressure / vacuum line

 

the hobbs switch is the boost sensor at a preset level it closes an electric switch. The switch sends current to the solenoid opening the valve this sends full boost pressure to the wastegate. the check valve is between inlet and outlet of the solenoid valve to let the wastegate close when boost drops.

 

So simple and not that expensive. I will test it before I put it into service but the theory is sound and the parts well proven. This should work.

Good luck

the parts have been ordered. Like I said this will be fully tested before I put it on the car.

Edited September 18, 200916 yr by vagen

Yeah - that should work fine. Basically you are building the industrial equivelent of an aftermarket boost controller. What you are really building is an adjustable pressure, compressor load/unload control. I know all about industrial compressor controls....

 

My concern is that it will not reload (close the wastegate) fast enough using only a single-way solenoid valve and your check valve trick - in fact thinking about it - a simple check valve like that would not allow the wastegate to close at all till the manifold pressure drops below the wastegate set point..... what would happen is the wastegate would get no signal till the hobbs switch opens the solenoid. Then when the solenoid closes again, the pressure would only bleed down through the check valve to what was in the manifold and if that stayed higher than the wastegate set point (4 to 6 psi probably) the wastegate would hang open till the boost dropped to below the wastegate diaphram set point..... not desireable since if you are running 10 psi of boost you want the wastegate to close anytime the manifold pressure drops below 10.

 

If it were me, I would just use a true three-way solenoid valve that vents the wastegate line to atmosphere when the valve closes - it switches the valve discharge line from one input to the other (which would be open to atmosphere). A regular 1/8" NPT 3-Way Asco valve should do the trick. No check valve to fail either.

 

GD

Edited September 18, 200916 yr by GeneralDisorder

thanks I'll look into that and pick one up if I can find one.

My old RX was a bit of a weapon - Was absolutely rooted, running on three cylinders most of the time (was just a farm hack, no point of fixing it, as was beyond repair) but used to boost something cronic. Upon inspection I found the turbo was actually a VF48 off the 2004 onwards 2.5l Impreza STIs......Goddammit it used to go hard, even when it was wounded - But I have no doubt that that turbo was the very thing that killed it.

 

All in all, upgrading the turbo is fine, but know the engines limits. It's not a strong engine, so raising the boost without some serious engine work is not the best of ideas. I'd go with a VF11 off a 2.0l GT legacy/liberty, then STI top mount, and a FULL PLUMBACK BOV. Don't use a vent to atmosphere kind, they might sound cool, but they'll ruin the turbo and/or engine eventually.

 

Also, a set of steel laminate race head gaskets and a better cooling system would do the trick - I'd go for a full alloy radiator - You could even get an electric water pump kit and run that for even better cooling. Plus, the electric pumps can be ran even after you stop the car, which eliminates heat soak. Bloody good idea - if you can afford it. They're not cheap.

 

Good luck mate

I have a radiator in mind for this car, we used it with great success in my brothers 86 hatch rallycar. It's all brass but crossflow and it cools like mad.

Chevy S10 v6 this fits the opening and mounts with little modification. I am also adding an RX-7 oil cooler for added protection after all our engines are primarily oil cooled.

 

when rebuild time comes I think I might pull out my Datsun hat and O-ring the block for better HG sealing.

Edited September 19, 200916 yr by vagen

when rebuild time comes I think I might pull out my Datsun hat and O-ring the block for better HG sealing.

 

Yes and you'll want to get some studs for the heads as well. They are an oddball size though so be prepared to pay....

 

GD

just took possession of the RX 210 miles to get it and 210 miles back. Needless to say I was nervous all the way back. even overloaded this car felt STRONG! and 10psi was right under my right foot no boost controller needed.

 

I need to redo the exhaust and chase a bad ground on the headlights.

Edited September 20, 200916 yr by vagen

I have decided rather than have a bleed valve boost control or a spring valve type I will build a simple electronic valve control. The parts list is short but it will work.

 

parts:

 

Adjustable N/O Hobbs switch

12v solenoid valve with 1/4 npt fittings

1/8 check valve

1/4 npt to 1/8 hose adapters = 3

1/8 tee fitting = 3

1/8 pressure / vacuum line

 

the hobbs switch is the boost sensor at a preset level it closes an electric switch. The switch sends current to the solenoid opening the valve this sends full boost pressure to the wastegate. the check valve is between inlet and outlet of the solenoid valve to let the wastegate close when boost drops.

 

So simple and not that expensive. I will test it before I put it into service but the theory is sound and the parts well proven. This should work.

 

Why not use the stock WGDS? It is a 3-way with a bleed orifice and everything... I agree with GD - you really should use a 3-way solenoid.

 

Your pressure switch has no concept of adjustable gain like a real closed loop boost controller; it's full-on or full-off. Depending on the hysterisis of the switch and the response of the solenoid, it could cycle on and off very quickly, which it's probably not designed for that. This would cause it to have a limited lifetime. You could also have limit cycle oscillations which would make your boost pressure unstable.

 

Either use an open loop controller like a simple PWM driver or use a real closed loop controller. Previously I made my own PWM driver and it worked pretty good but I'd like to up the boost a little more, closer to the limit of my injectors, so I just picked up a Greddy PRofec B spec 2 for $60.

Your pressure switch has no concept of adjustable gain like a real closed loop boost controller; it's full-on or full-off.

 

You can adjust it's response time with an orifice in the line to the pressure swith and you can dampen the open/close of the wastegate with another orifice in the line to the the actuator.

 

Depending on the hysterisis of the switch and the response of the solenoid, it could cycle on and off very quickly, which it's probably not designed for that. This would cause it to have a limited lifetime. You could also have limit cycle oscillations which would make your boost pressure unstable.

 

It will require some tuning to avoid high cycling, yes. But as those switches are used frequently in turbo applications to turn on extra injecotors or NOS systems, etc - I dont think it would have an extremely high failure rate. On the contrary, my experience is that, when properly maintained, the purely mechanical control's such as this would be, are often more reliable than their electronic counterparts. It's highly dependant on the system being used though, and one thing is for sure - a mechanical system such as he is contemplating will not be any cheaper than a used electronic controller, and will require more knowledge and tuning to get right. The electronic controllers are designed to be installed by your average 17 year old and hide much of what is going on in their programming.

 

GD

Here is the new car

 

 

 

Looks nice.

And it looks like I'm not the only one with headlight covers now.

yep I found them behind the seat.

First upgrade to the RX, do the 5-lug conversion using a mix of Impreza and XT6 parts.

 

Second, do an EJ turbo swap. I know people want to try and build an EA82T like Rob and I did once before too but in all reality, for the price to do the swap, abundance of aftermarket parts and the fact that you can make some serious power from an engine that has been proven to make it that doesn't need to be constantly rebuilt or repaired.

 

My old '89.5 RX was a nightmare. Thought I could build a decent EA82T but after 3 engines, lots of research and time, found it was actually almost 2x more money to build the EA82T for the 300hp mark then it would be for an EJ turbo swap and decent mods. I currently have under $1k in an EJ22T swap with Impreza 5-speed and 3.9VLSD.

 

I think Rob has about30k on his fully rebuilt EA82T and its having some umm.... issues:-\

Very minor.

I was told it hardly smokes any more.

It was probably some blow by caused by 2 dyno sessions in one week

But my upgrade is under my canopy as we speak

this EA82t is a fairly fresh engine so I'll keep it a while....

 

first upgrade new exhaust what's on the car hangs too low for my taste

second upgrade intercooling even the stock 7psi is high enough to need this.

third upgrade suspension that KEEPS the 4 lug I have enough 4 lug wheels to justify this.

 

fourth upgrade aero I need downforce so a splitter tray and wing will be fitted

I have changed my mind on the boost control and built a selectable system rather than an electronic wg control. I have decided to repurpose the Hobbs switch for I/C spray.

Edited September 22, 200916 yr by vagen