Hello all,

I have been interested in building a 6-port turbo fc since I got my car. I have an 86 gxl that I have nearly finished getting back up to speed (just need to figure out startup and idle). This winter I plan to execute this project and wanted to check with all of you to make sure I'm not missing something major. I have done a BUNCH of reading about other builds here on the forum and think I'm ready.

I will be using a megasquirt 2 for me EMS following aaron cake's install writeup
A walbro 255 for my fuel filter
whatever wideband I can get a good deal on at the time
either 550cc injectors all around or 550cc primaries and 720cc secondaries
port-match the turbo2 intake
use a stock turbo2 turbo with ported wastegate
generic fmic


I plan to use a sandwich plate for oil feed to the turbo and return the oil to the front cover. I haven't decided where I will get coolant yet because living in the northeast I kind of want to keep my heat working but I won't be driving the car in the winter so I don't think that will matter so much. I think I am ready for this project but I want to make sure I have all my bases covered. I'm not looking to make big power as of right now. just something reliable that has a little more pep than the stock NA 13b. If the engine lets go on me then I may Bridgeport and go for some big power but that for another time. Please share any experience you have with 6-port turbo engines and any tips you may have!

 

Hi I’m glad to hear that you want to try something different! Now for some advice or tips , as i have run multiple six port turbo setups. I would run e85 it adds peace of mind with high compression.

 

There is no e85 near me tho. I would have to drive about an hour to get gas. What about meth injection?

 

so a minor update. I think i have decided I am going to keep the NA intake and make the spacer for the exaust or a custom manifold.

 

I would definately go with 720cc secondary injectors. I think you'll find the car will boost creep a bit even with a ported wastegate.

 

what size turbo would you suggest then to avoid any boost creep? I thought when you ported the wastegate on the stock turbo that completely solved the issue.

 

Don't bother with a stock turbo for a 6 port turbo build. Invest in at least a hybrid turbo. I ran a bnr stage 2 for the longest time and made 350 whp. Since you've got a stand alone, go with 720 and 1000cc injectors. I also recommend running the fuel rails in parallel. Just swap in t2 intake manifolds right off the bat, they flow way better than the n/a setups.

 

Thankyou for all the input rotor head I will try to find a set of manifolds then if it is that much better. how long have you had your 6-port turbo? have you had ay reliability issues? what is your target AFR?

 

I've had my s5 6 port turbo on the road for the last 9 years with really no issues. I've had to clean injectors twice, thats really it. Having a more efficient turbo has helped keep the heat heat down in the intake as well as a good intercooler setup.

I have my idle afr between 12.3 and 13.0, microtechs like to run on the rich side. Wot afr is 10.8-11.0

 

I don't want to hijack a thread, but since this is relevant to the topic I think it's okay to ask.

What was your solution for port matching? The advantage I can see for the T2 manifolds is positioning the throttle body on the correct side and turbo clearance, but it looks to me like it would flow worse than an NA manifold due to the harsh bends (I haven't tried personally, but looking at it next to the NA manifold it seems restrictive).

The advantage of the NA manifold is possibly keeping the auxiliary ports functional, but you have to have a custom turbo manifold and even then it can be tight. And if you aren't keeping the aux ports functional, the advantage quickly disappears.

My thinking is that one could get a 6-port flange (LRB Speed has aluminum ones, I think) and use a die grinder to port match the manifold side to a T2 LIM, though this may require longer studs and slightly reduce turbo clearance. This avoids the slightly weird transition from just port-matching the manifold.

 

Simply put, you port match the t2 flange to the 6 port flange so you can bolt it up without having a leak there/be able to get air into the 5th and 6th ports.

I get people want to use the port actuators, I have not seen any downside to not having them with my 6 port with t2 manifolds.

P

 

Who tuned your car rotor head? And how much power have you been making for the last years?

 

Nelson Siverio tuned it last. It made 350 on the nose at 14 lbs on a bnr stage 2. Its currently got a bnr stage 3 on it that I added some fuel to the map and haven't been back on a dyno since

 

wow. is your engine ported? what seals are you using?

 

Stock port s5 block. Mazdaspeed/Mazda motorsports rebuild kit from back in the day. I think from 2000/2001. The engine has like 65k on it.

 

awesome to hear! I am almost done getting the car perfect in the stock form before I start gathering parts.

 

do you have a build page for the car so I don't have to keep asking you so many questions? Im sure I will come up with lots of little questions along the way like what size oil lines to use and such. would 10 an be enough?

 

I haven't updated it in years but here is when I first built the setup https://www.rx7club.com/2nd-generati...inside-890359/

An 10 AN would be fine

 

Thank you so much for all the helpful information!

 

I read through your build and I didn't see, where did you use for your oil source for the turbo?

 

Your easiest approach is going to be to port match the TII LIM. Once done, basically all the stock turbo stuff bolts right up.

Porting The 4 Port Turbo II Lower Intake To Fit The 6 Port NA Block

You're not going to be able to use the aux port actuators. Which wouldn't be an option with the manifold spacer anyway. To do so you'd have to build a custom turbo manifold to bring the turbo up and out towards the front of the car. Worth it? Not sure. Far as I know (correct me if I'm wrong) I'm the only one to try this on my Cosmo except for Cartech back in the day with their kit. Haven't fired the Cosmo yet.

Easiest approach for oil is to use a pedestal that has gauge ports. Use the appropriate fittings to obtain an oil supply from one of the ports.

Why MS2? At this point, MS3 is the current version and offers significant advantages.

 

I was going to go with the MS2 because of cost but I have decided to postpone this build for a little while until I have enough money to get nicer parts.

 

Probably a smart idea, no point ok n doing things twice.

 

That was my thought