I searched around but couldn't find what I was looking for. I remember seeing a list or a spreadsheet somewhere that showed different turbo sizes to power outputs somewhere on here. I decided to breakdown and go single on my next project for simplicity and reliability through said simplicity. If I wanted to run a single turbo at stock hp with stock porting what options do I have? I know these cars pump out a large volume of exhaust gasses and that can affect the turbo size needed to avoid over spooling. Any input on this?

 

it is possible to go too small... the rotary flows a lot of air. you want a turbo w an approx 6.3 sq inch compressor... the Garrett GT3582r is probably the most popular however it does have a fairly small hotside at 5.1.

take a close look at the Borg Warner S300 (Part Number 177280 and 177272) which has a very similar compressor but a 6.31 turbine wheel.

for further options see my sticky thread in the Single Turbo section... "Turbo Comparisons."

good luck

Howard

 

Thanks Howard I'll take a look at it. After fussing with my set of twins for a few months having them rebuilt and hearing the troubles the next owner after me had with 4 pairs of stock, jdm, and bnr turbos I figured it would be smart to avoid the whole sequential business if I wanted it to work every time I started the car. I've heard good things about Borg Warner turbos. Rob Dahm (some guy with a youtube chanel I've seen) has one on his 3 rotor and seems to have a lot of positive things to say about it.

Is the GT3582r the same things as the GT35R? Or is one a newer version of the older style? I've heard both numbers and wasn't too sure.

 

"Is the GT3582r the same things as the GT35R?"

there have been a few iterations of the GT3582r... the compressor has remained the same but the hot side housing has varied a bit... most just refer to the turbo as a GT35. the GT35 can come w a T3 or T4 rear housing. see ATP Turbo for choices or Turblown offers a number of excellent GT35 options including adding a P trim turbine wheel (5.89).

i believe the BW S300 comes w a 4.21 inch rear coupling (V band). if you decide on it you may find the 3 inch ($150) Full Race motorsports rear conversion worthwhile.

howard

 

Don't forget about smog. You won't pass the visual w/ a single in CA.

 

To be clear; you don't want to add any more HP than stock, just clean up the twins by going single? If that is the case you will need a turbo system that will maintain low boost pressures( something under 7/8 psi). This is hard for most turbo systems, as they aren't designed with priority waste-gate flow. Here is our turbo manifold, which has been proven to hold as low as 6 psi( even on a road-course).

More info, full kits, and turbos etc can be found here;
Turblown Engineering

 

Fritz Flynn has proven how reliable a standard old 60-1/TO4S is with a lot of track abuse. Its cheap and likely exactly what you are looking for around 10-12lbs(300-330rwhp). I will be running a Precision 5862 T4 billet setup later this summer as it looks really ideal for 300-400rwhp while keep much better response/torque than the stock non sequential twins. Just buy an HKS T4 cast manifold, decent wastegate and a proven turbo and you will be good to go for a long time with no worries. Not trying to prevent any business from selling you something else but that is a very cost effective simple way to accomplish what you are after.

 

That is correct I want to keep the horsepower as close to stock as possible. A little more is ok if I need it to feed the turbo itself. I'll be replacing the fuel system with the new 850 primaries and 1300 secondaries. I'm not sure about what ECU to use with this system because there are so many new options. I want to run Power FC because it is a classic setup with the FD but I could also run the new AEM EMS-4. A friend of mine is running this with his single turbo FC

 

I'm not worried about the smog part. I'll have it smogged when I buy the car and then have my 2 years to deal with it until it comes up again

 

Actually it night be more like 1 year now that the whole star smog thing has been put in place here in Cali.

 

Twins last for a very long time if you're not putting junk ones back on the car or trying make a bunch of power with them.

Being in Cali I'd suggest keeping the twins and just build the car correctly, especially if you're looking for stock-ish hp. I would not want to deal with trying to get a single car through SMOG in Cali. I have similar emissions requirements where I am and am stuck with twins for the same reason(though thats not a bad thing, just assemble it correctly with the right parts).

I mean, what will you do if you cant get the car through inspection? Sell it? Do all that work again back to twins, then back to single?

Also to pass idle emissions you'll need to stick with 550's if you're gonna be running stock style injectors, the 850's just dont clean up enough at idle from all I've read to pass in Cali. FFE rails and ID's will likely be fine due to how much better a new/modern injector works.

So you'll need an airpump and ACV which will be difficult to manage with a single.

Jason

 

I don't know why everyone thinks its so difficult to get a car passed in Ca. I know of 2 local shops who don't care about visual the inspection as long as it passes the sniff and still only charge 30-40 bucks. I find it harder to smog my commercial work truck here actually. Screw Cali for trying to make small business bleed money.

 

Back to the question about turbo selection, the T04z looks like a decent selection for a single setup. My question on the stock twins is who can balance these things and put together a set that won't fall apart on me? I spent a grand to have my stock twins rebuilt by Comp Turbo out of San Dimas and even sent them 4 turbo assemblies and said, "just pick the best two" and they still started to smoke after two months "/ is it really as hard as it seems to get a good pair? The guy that bought mine went through 4 pairs of turbos before going with custom twins because they all didn't work

 

That is why we don't offer to rebuild the stock twins, most of the time the cores are junk. If you want to keep the stock twins, I suggest you buy a new set of 99spec units.

The T04Z is way too large for you, that is 500-550rwhp turbo.

Here are a few very good choices;

Borg Warner S200SX 7670

Garrett T04E 60-Trim Turbocharger

Turblown Engineering TDX61 ( TDX57R variant in drop down)

 

BNR twins

 

After doing some research it looks like my choice would be to go with a T04E 60 trim. I was talking with a guy from Germany that runs the same setup on his FD and has it tuned to 294hp at .7 bar or 10 psi. He daily drives it and has taken it to Nurburgring a few times. I like the way it sits in the engine and with a decent fuel system upgrade and a power fc I think I will be just fine. Thanks for everyone's input! I always appreciate the feedback here on the 7 club!

 

Keep us updated!

 

Precision has finally agreed to 1.0 housings on the 62mm turbines for the rotary guys after begging that there was a gap that could be filled when looking for something smaller than a P-trim wheel but not too small as to choke the engine. Options that will be available are
5862 T4 1.0 divided and 6262 T4 1.0 divided. This will actually be a decent option as the normal "35R" turbine 62mm only came in either a .84 T4 "inlet" that wasn't ideal for EGT's and power, or a 1.06 that isn't ideal for stock ported engines and had a tendency to drop out of boost between shifts.

 

Wow! that's good news. What are the expected numbers on each? A guesstimate is fine, I trust you lol

 

Honestly a 5862 would be a excellent turbo for someone wanting to just get rid of the twins for simplicity, it would do wonderful on a stock port engine and with moderate boost is going to fall in the 330-400 range depending on mods and boost. Conservatively speaking a fast spooling 350whp car. Right now the options in this range aren't the best available. The 6262 will be a step up and very similar to the well proven 35R setup car since they both share the same basic dimensions on comp/turbine but with better response than say a 3574(TD variants for elliot) with the P-trim wheel or the 1.06 we've been stuck with on the 35R turbine and more power potential with the new Gen2 compressor wheels if someone wishes to push it. That turbo around 20psi will be a very responsive 400-450whp car. That would be thee "35R" turbo to get if response were the concern.

~S~

 

Thanks Sean. I like the stock ports personally. I'm not a huge fan of the peaky rotaries, I'm at least driving %80 on the street when the damn thing is running anyways, so a quicker spooling turbo sounds way more fun to me. When it comes time to rebuild I may open up the intake ports a bit but that's it I believe. Any guess on spool rpm on stock ports?

Thanks again for your educating me!

 

wow, i think a 5862 is in my future..

Jason

 

Has anyone really rung out a 5862 with a billet wheel? Curious what kind of power they can make when pushed into the 23+ psi range. As an example the CT3-5862 I picked up from Turblown is rated at 823 cfm (possibility of 428 hp on a rotary) at 1 bar, makes me wonder what kind of cfm it'll push when pushed up around the 23-25 psi range.

 

I haven't seen the 5862 from CT first hand so me commenting on it would be speculation at best. I have had a few customers run 5866's though and loved them saying they were very responsive with a .84 on the back. One went as far as to say he preferred his FD over his GT3 RS now. I was wanting back then to get those customers on the 62mm turbine with the 1.0 divided rear as I think some of them may have been a bit happier with it overall, but at the time precision wouldn't make them for me.


Response can be a bit of a guesstimate since a lot can effect other than just the turbo. I will say it's likely to see 7psi by 2400rpm and 15psi is likely at or before 3500rpm and feel good up to about 8krpm that's a pretty good power band. The compressor and turbine both have been ran to over 40psi and still showed power so there is plenty of room to push it if someone felt like it.

If someone had a 35R T4 that was running higher boost levels or very similar I'd be willing to let one go for a very good price if they we're willing to do a comparison with their old turbo and wanted something better.

On the exhaust ports for someone like you widening them a little bit can tend to give you some gain with little tradeoff since timing is not being effected, something to consider.

~S~

 

I wonder if a dual gate setup will be needed with the small 5862 to keep the boost down or if i can get away with the ultra simple(read reliable) HKS cast and the single gate?

Would want at best 400rwhp but 95% of the time i want a 350-375rwhp car with the fastest response possible. I have a lot invested into the twins currently but would love to simplify the car and i think with modern injectors and just a mild port i can keep it clean enough at idle to pass my emissions. I dont have to pass visual, just need a clean idle, which with the Pettit unlimited(not replaced with PFC, need to update my sig) and stock main cat it passed reading almost zero's across the board.

Jason