I ported my wastgate today, which took about 35 minutes from start to finish using a rotozip with a carbide bur. The wastegate was ported just a hair under 1- 1/4". I plan on using these twins along with the Greddy Profec B Spec II and a resonating MP. My ECU is the M2 ECU. ( Yes I know about the M2 ECU's and MP's). I believe that as long as I can control boost creep and spiking, I will be ok despite my ECU. People with the same setup ( or similar ) are encouraged to voice their thoughts, opinions and experiences.

 

nice work... i would say get a pfc and play it safe... my.02

 

Looks' like a pro job! But, is it cracked?

 

That look pretty damn good!
How in the Wide World Of Sports did you keep it so cylindrical?? (what type of guide did you use??)

 

Yes, there is a small crack there. I have seen other pictures of ported wastegates and others are cracked as well. I'm hoping that I will not have any boost issues given the crack does not connect the wastegate port to the main exhaust port.

 

At first I cut out a circle that was exactly 1-1/4". but after I opened up the wastegate I realized that when I placed the circle over the port I could not tell if I placed it centered over the port. I remembered someone saying they simply closed the flapper, and spray painted the area to highlight where the flapper actually sits over the port. From there, I opened up the flap and simply milled out the material by hand using the spraypaint as a guide. I held back a hair less than an 1/8" from the spray paint line. After that, Placed the 1-14" circle back on, and found that the hole was just under 1-14". I left it at that.

 

All and all I think you are right. I'm sure I will eventually get a PFC, but not right now. One thing that bums me out is that i really do not know of anyone in my area that can tune a PFC well- not that there is no one here that cannot, just that I do not know them....

 

Here are a couple of total noob questions.

How did you know how much to port? What happens if you port too much?

 

not a newbie question at all, I searched around and found several people saying that 1-1/4" was the way to go. It's pretty much logic, if you port the hole larger than the flapper, you will never have a seal, thus you will have problems getting up to boost.

 

Right on, Thanks

 

That crack wont do much. Dont worry about it. I've seen ten times worse that have had no issues.

 

I don't know if there's room on the FD turbo's, but us FC guys usually port ours bigger than the flapper, and use a larger flapper in place of the stocker. For instance, on the 87-8 turbo, the stock WG diameter is roughly 16-18mm if I recall. The one that is on my car, I ported to 30-31mm and used a larger flapper.

I cut off the stock one, and used a large flat washer (thick), a long 10mm bolt and nut (left slightly loose so the washer can still pivot and seal) with a small tackweld on the nut so it cannot back off, then I ground down the head of the bolt (that would have sat inside the WG passage) so help flow a little.

This turbo in stock form is supposed to flow 6psi...with straight exhaust and intake it can creep to 16. Mine stays steady at 6, even with straight intake/exhaust.

When/if I ever pull my turbos on the FD (if I am staying twin) I will port the WG as large as the housing allows and use a larger flapper in the same manner.

 

Sedley,

How long did it take to remove your turbos?

 

I wouldn't worry much about using MP with M2 ECU. Pettit ECU doesnt have any problems with it and its said to be more aggressive on fuel and timing.

What M2 probably meant with not suggesting a MP with their ECU is that you will get boost creep and kaboom. Afterall, their ECU is a bolt-on mod, whereas porting the WG isnt the simplest task in modding your RX7.

 

John , I did this on another set that I bought, so I did not have to pull the originals. (originals have 125k and are smoking). The next question will be whether or not to swap the turbos myself, or have a shop do it. I don't think it will be very complicated, just a PITA due to working postion(s). What do you think?

BTW, How's yor car coming along?

 

Yea those were my thoughts as well. When I dyno'ed my car with the stock ignition, it ran so rich that the air/fuel ratio dipped below the chart, so it was in the 9:1's or lower. I figure that if anything, my overly-rich map can't hurt. I've since upgraded to the HKS Twin Power, and seems to be better now- no more black smoke in the rear view mirror at WOT. I think with the addition of the greddy profec b spec II, a rsonating MP should be ok. If not, at least I wont be blowing a new motor. BTW, aren't you running the M2 ecu with Mp as well?

 

looks like you didnt mess up or anything...I want to add that you should get that crack welded and then sand it back down again then reweld and sand back down if needed. Have the welder do it right there it should take no longer than 15 minutes. Why put those on there and then wonder if you could get full boost 300rpm faster for example?

About taking off the twins yourself it will be a huge pain in the *** but you can do it especially if you have a garage just do about 30 min every night and label everything you remove. by the end of the week it wont feel like you did anything and youll be done

 

PBblaster......pbblaster......PBBLASTERRRRRRRRRRRR

 

yea, welding that crack would be a good idea. I knew I should have bought a small mig machine. As far as removing the turbos are concerned, there isnt much to it correct? Off hand I'd say you are dealing with the coolant/oil/vacuum lines, the nuts to the turbo manifold, and the DP right? What am I missing?

 

Yes I am, but its not 3" midpipe. Its more like 2.5" or whatever stock size is.

I should have full 3" exhaust installed in something like 2 weeks hopefully (midpipe + ntech catback just got sent this week from the states).

I will test it out for any boost creep and install a small restrictor if creep is a problem.

Hopefully I will run it at 13psi. And HKS TP is my next mod, but I think I ill get it dynoed first with correct AFR measurements.

 

So with your current setup, what kind of boost are you seeing? you will not regret the HKS TP. I ran my car WOT twice in a row, with and without the HKS TP, and the results were clear.....When you get around to dyno'ing your car, expect to see a large drop off in hp ( misfiring)up top without an upgraded ignition.

 

when you going to put on that turbo Sed, if you need help just let me know and I will help you put it on.

Kai

 

I use ProfecB and use 10psi on low and 12psi on high setting. I almost never drive on 12psi setting on the street though. I up the boost to 13psi for some drag racing and down to 9psi for track racing. No problems controlling boost and no spikes either.

I did already dyno my car and it did indeed start to loose power early on. But that was with restrictor, old plugs and wires and stock IC.

But I know HKS TP will improve greatly on that. Its just that I don't have $450 sitting around atm

 

I'll take you up on that offer if I decide to to it on my own, thanks!

 

How much octane is in your gas there?What are your mods again? I noticed that there seems to be two different ways to install the greddy profec, which way did you go and was it easy to install and tune? what dod you dyno btw?