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rabenne's street car

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Went for a cruise today with a buddy. He was in his miata behind me the whole time. He said it never gave the slightest hint of coolant smell, in spite of many hard pulls in front of him. But, after about 45 mins, the temps started creeping up and it was low on coolant again.... topped it off and back home, bummer.

I have checked for leaks at least half a dozen times now. I have run the system up to 28 psi (well above the 19psi cap I am running) during the leak check with no signs of external leaks.

So theres no evidence its going into the motor, and the only evidence of it coming out is whatever spits out of the tank. Something is causing 19psi of pressure in the system to be able to overcome that cap (I tested it myself).

I guess it HAS to be compression gasses getting into the coolant pockets. Fingers crossed its just an MLS issue and not a cracked block or cracked head.

Maybe next weekend ill be checking the head.... although it runs so well I am considering taking for a rip at the local drag strip before I tear it down. If I find a problem while its apart, it might be a while before its up and running again. I guess ill have to pay some attention to the auto awd at that point.
 
I def dont think so...

The cap has a plunger with spring responsible for creating the pressure in the cooling system. The pump just makes flow. If the cap plunger is pushed up by a pressure greater than the rating of the spring, it allows coolant past the plunger and through the small port on the water neck connected to the outlet hose for the res. tank.

If I am misunderstanding this... please clarify what I am not understanding properly

Edit

Here's a pic of the port, and from the other side, the water neck with cap installed showing the port blocked off when the cap is installed. The port should see zero pressure until the spring is overcome.

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20200817_102048.jpg
 
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okay cool... I appreciate the sanity check anyway! I make lots of assumptions and have nobody to keep me in check but you guys LOL

Its weird that the cap is bypassing at 2 psi, because the cap tester adapter says it is sealing to 19 psi. So I am going to buy a new water neck and see if I can get a cap to seal better on it. This one is between 26-30 years old... so it might just be worn in a way that isnt allowing the cap to seal. I dont see any obvious trouble on the one I have installed right now, but clearly something isn't right.

If 2 psi is pushing coolant into the res. I def need to fix that issue before I do anything else.

Edit:

my order got cancelled from the dealer bc its discontinued... awesome. I ordered one from extreme psi hoping they have one on a shelf, or can still get them. Fingers crossed, but I ordered online and didnt call to follow up. I guess ill find out...
 
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I had the same issue on my 1g a few years back, and tried several different things to fix it as well (different temp thermostats, different pressure radiator caps etc.) and also replaced the coolant neck. I was able to get mine through Murray, I believe. Not sure if 1g & 2g are the same, but that might be an option if the oem one is NLA. That didn’t solve my problem, and I ended up getting the head rebuilt, replacing the head gasket and all the timing components etc etc. But, no complaints from the aftermarket coolant neck.
 
Changed the springs in the wastegate to shoot for closer to the 25 I wanted. 33psi is a touch too high for a minimum boost pressure LOL. Those springs were supposed to be good for 25psi. I went to the 20psi spring combo, and ended up right around 26psi. Pretty happy with how strong the car feels even at the lower boost. I think getting some decent full pulls helps a lot.

We wanted to chime in on the WG spring rating vs actual boost level running "wastegate psi" as we've seen it on a few setups now and with talking to some prominent tuners.

The rated vs actual has been offset (higher) by 5-10psi on some setups, mainly newer higher flowing/more efficient turbos that tend to need more boost control to begin with. UHF Xona Rotor, PT6870, G42-1200 as some examples. The first initial fear was boost creep/insufficient wastegate flow but it's been the entire boost curve across the board and not just rising at higher rpm. The fact that swapping to a lower rated spring pack has an effect on the lowest boost that can be run says a lot, as boost creep doesn't care what the wastegate spring is and should make no difference. But it did, so boost creep didn't add up.
After talking to someone who has also seen it happen recently on some different setups they've tuned, they wondered if some of the springs had been mixed up or had variances in recent spring pressure/rating. Knowing TiAL's QC and attention to detail it seemed unlikely but we reached out just so they were potentially aware.

They answered that and more, but here is the short of their response:
The rating of the spring is based off there being a 1:1 boost vs exhaust pressure ratio (25psi of boost and 25psi of exhaust pressure to drive it for example) which is the industry standard, with some of that exhaust pressure exerting some "lifting assistance" to the wastegate valve and being part of the equation. If that ratio is skewed (very common) and EMAP is lower than boost pressure on an efficient manifold/turbo combination, then the actual/dynamic wastegate pressure will consistently overshoot the rating and "act" like a higher rated spring in the application.

So there are more variables to what each wastegate spring psi rating will result to in practice, and the boost skewing on the higher side than its rating isn't inherently bad (and more common than we thought) but rather a good indication that the setup is working very well. That is somewhat surprising as a divided T3 HX40 isn't typically lumped into the usual newer turbo tech suspects, but it would perhaps be more surprising if 2x MVS wastegates on your setup weren't enough boost control to maintain 25psi.

Also wanted to suggest swapping the L19's in one by one in order without removing the head. Making sure to keep the torque values what they suggest so it doesn't start to distort things but perhaps offer more resistance to the head lifting under boost. It's not the ideal way to approach it, but it may help since that setup is really good at generating a lot of cylinder pressure and we never happened to have good luck with the standard ARPs in that case.

Cheers,
 
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Thanks for the info about the wastegate springs. I had been thinking about that quite a bit! It makes a lot of sense!

For the ARP's I was def. considering doing 1by1. On one hand, I hate pulling something apart that runs so well, but on the other hand, I really would like to see the condition of the gasket and deck surfaces.... I guess it comes down to 'no harm in trying'...

There has been no real issues with boost control once I went to no solenoid and only the bottom ports. It holds consistent pressure ± 1psi to redline.

I really like the way the car feels, but it looks like I am going to have to step it down once more for pump gas. I had the car out last night and I was getting knock as full boost hit. My afratioest and wb are matching almost perfectly, so I added a bunch of fuel in the DA. 10.5:1. AFRatioEst and WB still matching well, but still got knock as full boost hit. So then I pulled 2 degrees from 4k up and made another pull - no knock, but lower than stock timing feels like crap...

Today ill re-spring for a bit less boost and see how it goes.

At 26 psi my best pull of the night read 623 HP and 587 FT.LB. Yes - this is an estimate - but it doesn't seem too far off from other setups I have seen. In 2015 a guy on here with a 2.3L and 60mm hx40 made 590something to the wheels at 27psi.
 
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Did you get to compare the VE tables with the only change being the turbo setup vs the 50 trim? Curious if there was a large bump in VE during spool and midrange
 
I have been slowly working on my table as I iron the kinks out of the setup and haven't had a chance to compare them side-by-side yet.

Last summer was my first time going to SD, so I am not sure I had a great VE calibration, but it ran well, so it should still serve as a decent comparison. There will just be areas in the table that dont make total sense or are a bit rough. The boost threshold doesn't feel any higher at all, and I have seen positive manifold pressure at really low rpm/loads. It does feel a bit laggy compared to the BB 50 trim. Above boost threshold, the 50 trim spun-up noticeably quicker for obvious reasons... That said, I dont miss the 50 trim... This car is quick now!

edit: to avoid another post I'm putting this in here... Extremepsi has processed my order for the water neck! I think that means they had one in stock...
edit:edit: they just sent tracking, SWEET!
 
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Blew a 2 inch slit into the lower rad hose... Something is very very wrong with this car LOL

This hose was new this summer... There must have been a ton of pressure to do that. Holy crap... I am not even sure this is a hg issue but I cant drive it around anymore... Time to park it until I figure it out and fix it with confidence. Going to repeat the leak down test when my buddy drops the car off... still on his trailer...

Bummer for sure! Might be the end of this car for the summer depending on what I end up figuring out.

All thats lacking on the auto awd is dumping the oil in it and testing out the new turbo. I guess I should stop neglecting it and pretending I cant see it...


Edit: Well, I got it home. Started looking a little bit for signs of why this happened. I pulled the radiator and tried doing some basic flow tests. First, Plug the bottom hose and fill the rad. Remove the plug and the radiator should drain 1) quickly & 2) completely. When I remove the plug, I get a very large initial rush of water, but after about half of the capacity is out of it, it slows down to a slow stream. After about 25 seconds the stream stops (feels like forever). Then I shook the radiator and it still had a LOT of coolant in it. It should drain completely unless there are blocked tubes, so that's another confirmed issue. After tipping it over and holding it sideways, and some shaking, it drains out about another quart of water. Please speak up if you think this is actually normal behavior! I am open to all opinions...

I'm not confident enough to say this would cause any kind of issue, but it might be... I am going to borrow the rad out of the auto awd tomorrow to see how it acts. Cant take it out to the normal country roads and get stuck on the side of the road again, so Im not sure how ill actually test it out yet.

I am also going to stick the L19s in just bc I have them. The new water neck should be here Saturday, and new mishimoto silicone rad hoses tomorrow (top at least).. might need to buy a 1g lower silicone hose in the future if the 2g doesnt fit my 1g t-stat housing setup. So for now I bought a dayco rubber lower hose to get me by.
 
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Today I used some degreaser on the inside of the radiator, letting it sit for a while then flushing repeatedly. I ended up getting a LOT of what looks (and smells) like dissolving rubber inside the rad. My initial tests were all from top to bottom, and I never saw much come out of the rad but water. But in my flushing today I turned it upside down and was appalled to see a shitload of black shit flowing out of the rad. There was way too much to think about re-using this radiator, and I am confident that EVERYTHING needs to be flushed really well. Even after all my efforts trying to flush it, it still has blocked tubes requiring turning it over to get the last of the water out...

Going to borrow the rad from the other 2g for a little while. I am not going to put the L19s in until I confirm this wasn't all just a really bad flowing radiator issue (and with blocked tubes - potentially trapped air issues). If I do both at the same time and it fixes it, I wont know if the radiator being plugged was causing issues or just making things worse!


The black shit:
20200819_155839.jpg


The hose that split:
20200819_125115.jpg



I cut the hose down the length to inspect the inside and saw zero signs of imperfections... based on a reverse flush getting the rubber out, I'd assume the top hose was the deteriorating one anyway.


EDIT: Got a whole bunch of light driving on the car tonight with the radiator from the auto awd in it. At around 5500 seconds into the log, I stopped and checked the bottle - still right around normal level- maybe a quarter inch higher than I filled it. Probably normal expansion.

Then I made 2 pulls, and checked the bottle. Bottle was full, and trying to overflow out the vented cap.

So the restricted radiator surely wasn't helping my situation, but it also was not the problem.... Tomorrow ill throw in the head studs and skip the 5500 seconds of cruising and go straight for a pull....
 
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Just threw the L19 studs in... after a bunch of reading and searching I decided on 96 ft lbs. Some have certainly gone higher, but I believe this should be fine.

If I still have head gasket issues after this I will consider what the best options are moving forward. Might be oring'ing a 2g head and going with the RVR manifold at that point. If this head comes off, why not put the 2g head on it?

I am giving the VC rtv a bit of time to dry, but should be able to do some test driving later tonight. Fingers crossed.


Edit: Made about 10 pulls tonight after getting the studs in. I checked the bottle several times between pulls. Never saw it bypass any coolant... After about an hour of cruising and making pulls, it did raise the level in the bottle, but not enough to overflow and dump it onto the ground.

I pulled it in the driveway and shut it down, heard a pissing hissing leak... So I pop the hood, and the radiator from the auto AWD that I borrowed is leaking from a damaged tube. Well shit! I should have pulled the fans to re-install them myself, as I might have seen signs of trouble before hand. I just swapped the rad and fans from one to the other. Now im out of rads. Might as well go with a 1g and get that top hose away from the manifold now.


It looks like the hg MAY have been the cause of my coolant loss this whole time... but I dont think I can consider it fixed until I have a few successful drives without pushing all the coolant out.
 
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To deal with the radiator issue I ended up buying an open-box x-line radiator from amazon for a nice price. As long as it shows up okay ill use it, and if it doesnt, it should be easy to return and buy elsewhere.

I also ordered 2 Spal 12" paddle push fans. SPAL 30102025. They claim to flow 1640 CFM each. They are kinda thick/deep with the pitch on the blade design, but it looks like they should fit fine on the front side of the radiator. The plan is to wire them from the fuse block with a heavy gauge wire to a relay, and use ECMlink to trigger them on under 20mph and over 180degF. Might also wire in the AC switch as a trigger for manual control.

ace8311e48700641784a6e80ca93156f.jpg


Mounting them will be the tricky part. With their thickness I wont be able to attach them to the rad and then install it while the exhaust manifold/turbo is on. So ill probably make a "shroud", but more as a durable and reliable mounting solution. A shroud would actually hurt flow on the front of the rad, so it will be more of a bracket... Also plan to spend a bit of time sealing the FMIC to the rad/rad support.



Edit: Shipped today, due Thursday. LMPerformance was the seller. I was a bit skeptical ordering from someone new, but then the parts shipped from the same exact distributor, Turn 14 Distribution, that ships for MAPerformance out of Reno, NV. So it was the same as purchasing from them essentially.
 
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+1 on that... I think it was a deteriorating hose, but I threw the old ones away, so I cant check to see their condition on the inside...

Its weird to think I could have been so close to the edge on the standard arps when you consider people have made real power with them... If that truly fixed it, then there must have been some stretched studs from over-torque or something like that. I keep forgetting to measure and inspect the ones I pulled out of it.
 
You are going to LOVE a twin scroll @MorrisonFab manifold.
My son has an HX35 on this car and it has a stock converter. I Can't even get on my converter like this. I'm sorry I was behind the house when this went down, testing my 7 bolt build the other day but I had no idea he was going to do a pull.

MUCH respect for your choice!!! You will be sooooo happy! :thumb:
I am still waiting on NOS for spool on my HX40 but.....is this the same housing Will?
It will clean up if so. I need better spool.
Marty
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Looks like thats an 18cm2 housing. It should spool pretty well and wont limit your flow as quickly as what I am running. I am using a 14cm2 right now, and I also have a 16cm2 housing with the same footprint that I can swap in later if the 14cm2 housing appears to be my limitation at some point. They are non-internally-gated housings as well. A while back in this thread a guy showed one of those housing being modified to ditch the wg provisions and make it a v-band out. The discharge of the one's I have are 6 bolt round flange.
@1990TSIAWDTALON, What housing are you currently using on your HX40? Open t3?


I keep looking at the auto awd as an organ donor... I should just convert now before I break this transmission LOL
 
Yes I am running an OPEN T3. That TS spools so nice. If you go that way, it will be a good route!
 
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