Just did some research on the Apexi RX6 kit, seems like a lot people have problem with the wastegate that comes with the system. Potentially it can overboost and cause engine damage right? Buying another wastegate can solve the problem but they are not cheap, any recommandation?

Is it possible to set the boost to 10 and 15psi? Do I just change the spring in the wastegate? How can I do it? Thanks.

 

Is there more than one version of this turbo kit? Some on the forum think it does not retain the airpump, I was not understand that impression.

 

FYI, I have the version that allows you to retain the airpump. The older RX6 kits do not allow you to retain the airpump but the newer one (the one I have) has a shorter exhaust manifold, so the airpump can be retained. I got mine from Tony at www.rxecret7.com call him for more details, as I believe I am the only one thus far that has this kit so I don't know how he got it but needless to say, i am pleasantly surprised.

as far as the wastegate goes, there are two routes you can take if you want to play with it:
1.) do what maxcooper did and buy the hks ss wastegate, it fits pretty well right on to the apex'i manifold. pm max for more details
2.) do what XSPower recommended on the forum. Take the wastegate apart and have the valve guide honed .003 bigger.

I went with the latter route, since $20 machine shop bill was cheaper than $500 for a new wastegate. Since then I have taken it onto thunderhill raceway in 95 degree weather and ran the car at least 3-4 hours at high rpms and had no problems whatsoever.

 

All of the Apexi kits now let you retain the airpump. It doesnt really matter, on Oct 1st nobody will be able to afford the kit

Jason
www.rx7store.net

 

Or you can leave your wastegate alone and install a pop-off valve as a safety, right?

For what it's worth, the local shop that's putting my RX6 on is happy with the quality of the Apexi wastegate. They've done 7 kits and and have not had any trouble out of any of them. But then again, I'm not sure how many singles really show up to the track. I know maxcooper had a failure, but have others? Not sure how isolated a case this is and if it's just gotten blown out of proportion. It would seem Apexi would be liable if their products were known to fail causing catastrophic engine failure.

 

The problem with the wastegate appears to be associated with prolonged high output conditions (such as on the track). It is just my opinion but I would strongly urge the use of a pop-off valve whether you modify the wastegate or replace it with a Tial, HKS or anything else. It is just a $100 and makes for great insurance in the event of any number of possible failures which would result in an overboost situation.

 

someone on the other thread said that that was for their new apex'i kit. I also asked tony and he said that the new apex'i kit will come with a better wastegate among other things.

the wastegate is underengineered. What happens is when it gets hot, the valve stem expands and then gets stuck on the valve guide and then the wastegate sticks shut and then overboosting occurs. This is most likely to happen in a road race condition and probably wouldn't happen while drag racing or on the streeet. I did XSPOWER's recommendation and had the valve guide honed out.003 bigger. I took it on the track under very hard driving conditions and had no problems with it. Therefore, it's good enough for me to keep.

 

I've seen the new Apexi kit (meaning allows retention of the stock air pump) installed as early as March of this year, when mine went in (mine is of the previous type, cannot put the stock airpump back on).

I am going to work around this by installing a LS1 electric airpump, and use the original pump harness to trigger a relay to turn it on and off. I kinda like this idea better, as that it takes one more thing off the belts (more aesthetic then anything else), and I can tuck the air pump away elsewhere.

Some people here have said that you cannot run the LS1 airpump for an extended period of time (or it will burn up), but friends that build and race Camaros/Firbirds say it will be fine. I'll be the test subject I suppose, as I really do not like stinky exhausts...

Here is a pic of the previous kit on my car. As you can see, the turbo sits roughly where the airpump went.Maybe 1F'titeFD can post a pic of his to so how it now sits.

 

I also have the newer kit that allows the airpump to be retained. I can also get them, and have one for sale new in the forsale forum. As far as the kit I havent heard any problems with people using the kit that arent using it for prolonged periods of time at high output

 

Is there any problem if I want to set the boost to 10 and 15 psi? I heard the wastegate only works from 15 and above. How much are you want the kit for? PM me only if its the newer kit. Thanks.

 

Here's a picture of my engine bay:

http://www.pbase.com/image/3657519

you really can't see the turbo, but notice how it's not where dclin's is. If I didn't have my intercooler pipe going through it, I can run an airpump if I wanted to. When I first got the turbo from tony, I didn't know that I would be able to keep the airpump, but after installing it, I found out I had the newer version. It didn't matter to me considering I was going to toss the airpump and run a straight pipe anyways

 

just get a boost controller. that will hold the boost to what ever you want

 

My wastegate would stick open a little on the track (giving poor low end response, but it didn't matter much on the track). On the way home from the track, it stuck shut and I had a mega-overboost. I think it was more than 30 psi, perhaps more than 40 (my fuel pressure gauge was holding a peak of 85 psi, and it reads 40 psi at zero manifold pressure with the stock regulator). It broke the tires loose and spun them like mad in second gear. It was really fun for a few seconds!

I replaced the wastegate with an HKS SS Racing wastegate, which is easy to adapt. Search for my thread on the subject if you want details.

The wastegate seemed to be fine on the street. It would probably be fine for AutoX and drag racing, too (but this is just a guess, as the engine is under load for a much shorter time -- be safe). It seemed like it was just the road racing that would make it stick. Once it cooled, it seemed to un-stick itself. If you don't plan to road race, the wastegate will probably be fine, but it might be a good idea to get a pop-off valve just in case. The same is probably true for any aftermarket turbo setup, as they are subject to less testing than OEM setups and sometimes take some "sorting out" to route the hoses. I should take my own advice, but I still don't have a pop-off valve.

-Max

 

Max, did the "poor low end response" came from the problem of the wastegate or that's just how RX6 feels compare to stock?

 

For the record, I just got back from a weekend at MADS, and didn't have any wastegate problems. I only got the car back Thursday night, and didn't have a chance to get a new wastegate or popoff valve, so I just went for it. I'm still breaking the engine in, so I kept boost at 9psi, but toward the end of the weekend I was staying in it for extended periods of time. Fortunately there weren't any problems. I think I'm going to go the route of getting a popoff for safety, but leaving the wastegate alone until it actually fails.

On a side note, what are you guys doing with your dump tube? I didn't think to check beforehand and thought it would dump back into one pipe that goes to the cat/midpipe/whatever. Custom exhaust job? This thing's just a liiitttllle loud for the street! I really don't need any extra attention when I'm at high boost!

 

Yup, true of all turbos that have WGs that vent to atmosphere. Annoying as hell imho, but some people like it. I'm going to have a new pipe made to replace the dump 'elbow' and route it back to the beginning of my hi-flow cat (with the idea that the WG dump reentering the exhaust as far back as possible would be better), at a shallow angle. I've also already ceramic coated my dp, so do not want to ruin/redo the finish hehe.

Will probably have to have a flange to split it, since it's going to the cat. Any hiperf shop with welding experience can handle the job, and maybe even the local muffler shop if you have not choice.

 

http://www.geocities.com/valspeed/

Click on 'Engine' in the left menu, and you can see pics of the WG dump routed into the dp.

 

Thanks for the reply. Looks like I'll be making a stop by my local muffler shop. One-man operation who did a totally custom exhaust for one of my other cars and it was truly a work of art.......

But first I have to set off a few more car alarms, break a few more windows, and make a few more babies cry

 

Great pics, by the way. Thanks again!

 

Jeez, you have done a lot of work to that car! I was wondering, I see the altenator...what happened to the waterpump? That is the most custom work and one of the coolests cars I have ever seen!

 

Umm, I wish it was mine guys. That's Mark Valeski's(sp?) CYM, of Brembo brakes fame. (need $8K FD brakes? He's the man) Mine is the Silverstone a little further up in this thread hehe.

 

Mark has done a really amazing job re-engineering the car. All the parts and work are top quality. The stock water pump is gone and replaced by an electric pump -- I think it is the black unit mounted to the right of the radiator when looking from the front.

-Max

 

Problem related to the wastegate seems cause by the bushing. Apexi uses some kind of rubber or copper bushing inside their wastegate. So when operating in extremely high temperture for a period of time the bushing tends to stick and stay close. When the temp. drop down it's back to normal again. Apexi is aware of problem and came out with the fix (I was told). In their newer kit they now uses SS instead of the old material. You can check your wastegate by looking inside, if you see silver bushing, congraduation you got the newer style. If it looks black or brown then get a pop-up valve to protect you investment. Cheers.

-OY

 

tailhappy, was your car the black one at rotorsports recently? i liked that one

 

Yeah, niner, that one's mine. It's not super clean but I'm a big fan of the "sleeper" mentality. Looking at the outside you'd never know what hides within!

Was your car there? I saw a midnight blue FD and a montego one when I was picking mine up. Plus the silver one, but I know who's that is.........