MR2ocnz 25th Turbo Preperation

[Benckj]

Decided to use the upcoming event to get a few things sorted on my car. As I'm up to date with all the boring maintenance stuff I wanted to get my car to accelerate better as the upgraded turbo installed wasn't delivering as expected. Problem was determined to be a restricted internal wastegate port and poor flow charteristics. This caused uncontrollable boost spikes in the range of 18-19psi. Hard to drive the car as it always wanted to overboost but my controller would knock it back to 5psi and the cycle would start again.

My simple solution was to install a new 'screamer' 38mm pipe from blocked port to free up the flow. After talking with a local Tuner he suggested that a new port be added from the scroll case to an external gate. Like any other MR2 space was going to be tight and I had my reservations if this was the best solution.

Thought it would be best to start a new thread so I could record my mod. Pics below of the engine bay, Kinuwga TD005SL2-18g with extended tip billet wheel & high flow turbine.

[Benckj]

Will add more info here to go along with pics.........

[Benckj]

Nothing goes to plan with these cars when undergoing mods. Wanted to install the DP and external gate so I could tune over the weekend. Managed to get it all done but on first engine start I had a massive oil leak. Narrowed it down to my oil feed hose which I somehow 'damaged' while working on the hot side of turbo???

Pulled the feed line and re-terminated twice without success. Figured this was probably something which was going to fail anyway so ordered a new braided hose today. Will need to remove it again and see if I can reserrect the fittings. All going well should be able to have car roadworthy this weekend and get some good tuning runs in.

Last thing to do will be to install my wider tyres and transfer the TPMS over from wifves Audi. Wish my touchscreen worked with the remote TPMS system but when it does the Shadow Dash program drops off-line. I'm not much of a Droid programmer so need to pick someones brain on how to get these to work together.

[tw2]

You are brave welding to the turbine housing!

[mickeyduck]

Have you got a freakin' dyno at home Jim?

[Benckj]

Tuning shop did the welding on turbo as they have done on others. If it causes any issues I can buy the hot side scroll without gate for reasonable price. I coated with high temp ceramic paint so any stress fractures will be easy to spot.

No dyno at my house as at local garage. It’s not the best but good for tuning and he doesn’t charge much to use. He even lets me do runs and mod car without removing off rollers. I still find road tuning the best as have some decent hills to climb.

New oil supply hose ordered this morning do hope it’s delivered tomorrow. I’d probably rather have a hardline for this supply so may build one this Christmas. Losing faith in these hoses as it’s the 2nd one to cause unexpected problems.

[GDII]

That's looking really good. A good solution to control boost better. Well placed too in the flow direction of the exhaust gases.

There is a reason why the OEM hose is a hard line. Takes far more abuse without breaking.

Good to see you moving forward with this problematic turbo. I hope it goes well for holding reliable boost levels. Nothing worse than an engine that wants to grenade itself.

[Benckj]

Yea hopefully this solves my boost spike issues. I think the turbo is a very good design but wastegate is rubbish. By increasing the compressor wheel and installing a high flow turbine it only made the problem worse. If I was prepared to run at 22psi it wouldn't be much of an issue.

With any luck my replacement oil feed hose will arrive today and I'll work on replacing this tomorrow. Might make a heat shield for it to keep away from the hot side of manifold. Eventually I'll replace with a hardline which won't be much of an issue to do as I can adapt the fittings being used now. Any recommendations on tubing to use?

[GDII]

What was the reason for failure? Hose fittings or hose itself? If it's only heat then putting a fire sleeve over it and a heat shield with an air gap will help.
Maybe using full steel fitting instead of aluminium would be better too. I'm not sure if I'd be using NZKW fittings for a critical application like this but I don't have a way of comparing the quality to something else of a 'better' brand.

Based on some quick research all the good feed lines have steel end fittings.

[Benckj]

It looks like it failed where it joins into connector on turbo end. As I removed the hot side of turbo this line was moved around several times which I speculate dislodged it from the crimped connection point. After removing and re-seating connection the oil flow decreased but was still bad. Possibly split the end of hose which could be trimmed back but difficult to obtain a good seal.

I’ve ordered more hose and will install along with a heat shield made from metal tape. Later on I’ll attach hardline onto the alloy fitting that attaches onto metal banjo bolt. Just need to find something which won’t melt under the exposed heat.

[GDII]

Oh right. That sort of makes sense. What fitting type are you using? 500 series?

Other than the hose which is annoying the welds and fittings on the turbo look really good.

Is that an EPMAN waste gate? Hope that lasts long enough.

[Benckj]

Oh right. That sort of makes sense. What fitting type are you using? 500 series?

Other than the hose which is annoying the welds and fittings on the turbo look really good.

Is that an EPMAN waste gate? Hope that lasts long enough.

As recommended when I installed previous turbo I used the 100 series which is only rated to 185C. I think the 200 series is 220C which would be better. Hardlines are the best IMO.

The wastegate is a EPMAN and thought I had ordered the water cooled model. The Tuner I use has good reports of using these and the size was smaller than Turbosmart & others. Final placement isn't as shown as it was only tacked together for checking. Ended up rotating it under the DP a bit further as it was hitting the dip stick. I'll see how I get on with this set-up and if I need to replace WG or oil lines I can work on over Christmas.

[tw2]

Are you sure it is just wastegate related? If it is able to bring you from 19 to 5psi that would suggest the flow is fine and maybe a control/signal issue.

I have never had any issues with aeroflow or earls fittings for high temperature oil feed lines. ATS sells steel ones I think. The only issue with hardline is vibration. The fittings are huge on the stock lines. I would try and use a banjo end with stainless braided line if you want a more robust fitting at the turbo end. Aeroflow sells them on trademe. 4an will be plenty big enough in any case.

[Benckj]

Are you sure it is just wastegate related? If it is able to bring you from 19 to 5psi that would suggest the flow is fine and maybe a control/signal issue.

I have never had any issues with aeroflow or earls fittings for high temperature oil feed lines. ATS sells steel ones I think. The only issue with hardline is vibration. The fittings are huge on the stock lines. I would try and use a banjo end with stainless braided line if you want a more robust fitting at the turbo end. Aeroflow sells them on trademe. 4an will be plenty big enough in any case.

Not entirely sure its a WG problem but they way it reacts to my EBC sure seems that way. I have the EBC to drop the pressure by a certain percentage once it reaches overboost set-point. My interpetation of the problem allows the wastegate pressure to feed straight into hot flow at 90deg which effectively stalls the turbine. Have tried to control using my Response setting with EBC and have it virtually turned down to 3% but I still chase these boost spikes. If I dont' put my foot into it I can control the response but this is not how the car should be driven.

Think I will need a robust system for oil feed to turbo. I had a banjo with crimped fitting but ended up having the rubber deteriorate and leak due to heat after engine shut down (with 30sec turbo timer). This seemed to be the biggest issue as when driving there is always enough air flow through engine bay to keep vented. Keep in mind I run an A2W IC directly over exhaust side and use the factory heat shield over manifold & turbo to reduce radiation which tends to trap heat in this area of concern. The new wastegate sits outside of this shield so hopefully it doesn't become toast.

Keep the comments coming.

[GDII]

I'm sure you have tested this before but have you run wastegate spring pressure only without the controller active? What were the results of that?