1FooknTiteFD

After many months of pondering, I've finally decided to go with the Apex RX6 kit. So far my mods include, M2 medium Ic, M2 intake, n1 dual exhaust, m2 downpipe, and m2 ecu, and bosch fuel pump. What other things do I need to properly set the car up? I'm planning to go with the Power FC, but i've been told to get another boost controller such as the AVCR for a single, and to also get 550 primary injectors and 1300 secondaries. What else do i need? Do i need an ignition system or anything else? I'm not planning to make big horsepower, maybe only 330-340 rwhp at most, running only 11-12 psi on 91 octane, and on the track i'll raise the boost to 13-14 psi on 100 octane.

maxcooper

Your list sounds good. I am running the RX6 with the PowerFC, 550/1300, and an AVC-R. I cut an old, straight pipe from my M2 Medium to connect it to the turbo, but I would probably get a custom-bent pipe if I did it again (and probably will do that soon). You can sell the M2 intake, and I am sure there will be lots of eager buyers for that item. I relocated the A'PEXi filter with some 90mm Santoprene hose from http://www.mcmaster.com/ and it works great.

If you are going to road race, you might find that the A'PEXi wastegate does not stand up to the abuse. Luckily, the reliable HKS S/S Racing wastegate is almost an exact replacement. It has the same bolt patterns, except for the WG dump tube which is so close that you could probably just slot the holes. Otherwise, I think the A'PEXi wastegate is probably okay for street and may survive drag racing usage as well. Mine would stick open on the track and kill low-end response (which doesn't matter much on the track). It eventually stuck shut and gave me a huge, motor-breaking boost level.

Since this drives the price up considerably, you might consider the XS T04E kit. It is said to have better spool up, the turbo is rebuildable if you throw an apex seal at it, and although it makes a little less peak power than the RX6 it is certainly capable of meeting your power goals.

Also, you probably want to get the wastegate dump tube routed back into the downpipe to reduce the noise level when the wastegate opens. It doesn't sound as cool as you'd think it would -- more like an exhaust leak.

-Max

1FooknTiteFD

max, thanks for the reply. I am planning on road racing it with the apex kit in. What's wrong with the wastegate? It's kind of disturbing realizing that I need to get another wastegate added on it like another wastegate. What types of problems have you run into? What modifications are needed to fit the HKS wastegate on it? Can you post pictures of setup? As you can see, I still have a lot to learn about single turbos and set up. I really wanted to get the greddy TD06-25g kit but I can't get it unless i go to japan. That's why i'm settling for the apex kit, which everyone has been raving about.

maxcooper

I think the A'PEXi wastegate just can't stand up to the hot rotary exhaust. Mine failed by sticking open on track, and eventually stuck shut, wounding my motor. The wastegate is completely stuck right now, so my right foot is my only boost control.

HKS and TiAL are the two manufacturers that seem to know how to make reliable wastegates (from all the reports I have seen). I bought a TiAL to replace my A'PEXi wastegate, but then I found out that the HKS S/S racing wastegate will bolt right up to the manifold with no modifications, so I sent the TiAL back and got one of those. I just received it last night, so I haven't had a chance to install it yet. The only thing that I know I will have to do is slot the holes in the wastegate dump tube flange a little bit. I'll probably post some pics of the HKS wastegate on the A'PEXi manifold soon (within a few weeks).

I like the performance of the A'PEXi kit, but I think it ends up being an expensive setup once you replace the wastegate. The XS T04S kit comes with an HKS Racing wastegate, and you could probably ask them to upgrade a T04E kit to the Racing wastegate as well, if you want it. The Standard one might be fine, too, but I always hear people say the HKS Racing wastegates are reliable. The S/S Racing that works with the A'PEXi manifold is different than the regular Racing one, too, but I would assume it would be at least as reliable as the Racing (I think only the valve seat is different, and it is better).

-Max

RX7-2JOCK

Sup Vic.......How much is the kit your getting ?!? And who are you getting it through ? I plan on going single too, but I'm saving up for a new motor first, and when I get the new motor installed I want to dump the single in at the same time......

1FooknTiteFD

Dean i'm getting it from Tony at Rotary Xecret 7, he's going to hook it up. what single are you gonna get dean?

Max, are you running the m2 intercooler also? If so, can you please post some pictures of your setup?

maxcooper

Yes, I've got a Medium on my car. Pics here:
http://www.maxcooper.com/rx7/gallery/mycar/index.html

I have since installed a TiAL BOV on the pipe between the turbo and IC, mostly because that was the only place it would fit.

That's another thing you'll need with the A'PEXi kit -- a BOV. Chris at Xtecheng.com has the TiAL for a very good price. It is a nice unit. I imagine that Tony could hook you up with something nice, too, like an HKS or something.

-Max

1FooknTiteFD

very nice max, my kit will loook something like that when i get it =)

Do you run the car on the street with 91 octane gas? How many psi do you boost on the street? Would you say that the single turbo is more or less reliable than the old twin turbo set up? Also do you road race or drag race? I'm planning on running it on the track for hours at a time so I need to make sure everything can hold up.

maxcooper

Yes, I always run 91. I don't want to run race gas all the time, and you have to tune the car for one or the other, so I just run pump gas all the time. Even at the track.

I have been boosting about 13 psi, but since my wastegate got stuck it shoots up over 20 sometimes (before I let off), and I think my killer boost run was north of 40 psi (based on the peak fuel pressure I hit). Surprisingly, the engine is only slightly damaged, so I think I should be able to run 15 psi all the time with no problem. 15 psi on 91 octane all the time is my plan.

I think the single turbo could be more reliable (and consistent) than the twins after the bugs are worked out. But working the bugs out is expensive (take my advice: get an HKS wastegate), so it would be hard to characterize my experience as "more reliable after I went single" yet. I think it will be, though. And it has been much more consistent in its operation -- it does the same thing every time you squeeze the throttle (well, until the wastegate got stuck shut anyway).

I road race, too, and I want a 400 RWHP car that will run all day without breaking or overheating (a tall order!). So far, everything but the wastegate has held up well for the two or three track events I have done with the single at 13 psi. I did have some downpipe fasteners come loose, too, but they were easy to fix and didn't break anything.

-Max

1FooknTiteFD

max, thanks for the advice, i'm going to be running about 11-12 psi on the street and maybe 13-14 on 100 octane on the track. I'm looking for something that's simple and reliable, plus i'm only looking to make about 330-340 rwhp, so I just want somethign that would hold up plus give me some good power all around. How does the lag compare with that of stock twins? is it a lot worse or is it better? If you could do everything over again would you still have gone with the RX6 or something else such as the XS turbos??

1FooknTiteFD

hey max, i just checked out your webpage, you have a very nice car. It looks like i'm going to run a near identical setup as yours so why dont' you post your maps in the power fc section?? BTW, how much did you get your twin power ignition for?

Sidestick

iTrader: (1)

What's wrong with the Apexi BOV? My XS kit comes with one & now you've got me worried!

maxcooper

1Fookn,

Thanks for the compliment on my car. It has been fun to build up. I don't know what my maps are because XS tuned the base maps and I don't have any way to see them (no datalogit, yet). I got my TwinPower from Tony for about $450 before tax (I think it was $486 including tax).


The A'PEXi RX6 kit does not come with a BOV, that is what I was talking about. I wasn't talking about the A'PEXi BOV.

-Max

1FooknTiteFD

I've been told that the apex'i bov and wastegate both suck. For BOV, tony recommended the greddy type r, and the HKS racing wastegate in place of the apex'i one that comes with the rx6.

Max, what track do you drive on? My friends and I are renting out thunderhill over the summer, if you are in caliornia, you are welcome to join us