It seems the more I read the more confused I get when it comes to picking a turbo. Initially I was going to run the stock twins, however due to space limitations they are not an option and I have to go single. I'm looking for something that's quick spooling to feed my bone stock 13B-REW. Preferably something that starts spooling up around 2.2 - 2.8k rpm and makes good power. Not looking for dyno queen power but rather enough to put a grin on your face. Ideally something that will hit 350hp with the possibility of hitting 400 in the future. Now the fun part, I only have around 5k to spend and that will include the cost of the Link G4 RX that I'm planning on running.

Forgot to mention this will be installed in a lil 2200 lb chassis.

 

Is this going into a kit type car?

You're really going to need to look into potentially expanding your budget with regards to going single. $3k will get you a good turbo kit, but you're also going to need to address all the supporting modifications like fueling, ignition, cooling, boost control, etc., as well.

I'm not aware of many single turbos that will spool by the time you'd like them to, while still producing the power that you're looking for. A set of sequential twins (BNR Stage 3's) would get you there, but you said those aren't an option due to space limitations.

If you can more fully explain what your situation is (current mods, chasis used, what it will be used for, etc., etc.) we may be able to help out a bit more.

Cheers,

Levi

 

The few supporting mods that I already have budgeted is a new secondary fuel rail, 1600cc secondaries, walbro 255 and full 3" exhaust. Was going to utilize the link for the boost controller. The car is being built for the street and the occasional cone chasing in a parking lot.

The engine is being installed into a Miata so that's why the twins wont fit, literally two inches too wide. So I'm going to sell the stock twins, associated wiring, and 3" downpipe and re-invest it into the intercooler and plumbing for the build.

I've been looking at the GT3574 kit from A-Spec as the price is right and seems like the power levels will be in the range I'm looking for. The only thing that concerns me is spool time. In essence when at cruise rpm (around 2.5k - 2.8k) I wanna be able to step on it and not wait for the turbo to spool up before it starts pulling.

 

Gotcha. Yeah, you're going to have a hard time finding full boost that low on the rpm range. I've got a-spec's pt6265 kit, which is just about the same as the 3574 except mine is billet. You can always down shift to get the turbo in its happy range, the only problem is traction at that point. (350-400whp in a Miata is a LOT of power!! And the 3574 will make that easily.)

Have you considered water injection as a supporting mod yet?

 

Though, yeah. Def speak with Sean (A-Spec) about what you're looking for power and response wise, he'll bee able to suggest a good combination for you.

 

Gtx3576

 

^ The thing is, he's on a bit of a budget and probably won't be pushing the turbo high enough to take full use of the billet properties anyway. So getting a GTx over a GT is probably just money he could spend elsewhere.

 

I was thinking about water injection but decided that if I need the extra cooling will switch to E85 (one of the reasons for the Link as it has native Ethanol sensor use should I need it). Unfortunatly the Billet wheeled GTX's just aren't an option for my build as I'm limited on funding. It's also why I'm asking for help in picking a turbo from the experts, because I'm poor and don't wanna screw up picking a turbo I won't be happy with.

 

GT3574 is 500+HP turbo. For your power goals, T04E with 57 or 60 trim compressor and P-trim turbine in 0.84 A/R divided housing would be better choice. But I must admit, whole GT3574 kit seems very nice and will produce power you are after. Fact that your engine is stock port is actualy very good for low-end power and response.

In reality, there are many turbochargers that would meet your goals, but taking into account funding and what has been proved, Garrett is probably number one choose. For example, BorgWarner does produce very interesting turbochargers with rotary friendly sizing, but compressors are rather high PR oriented and IIRC turbine housing needs some modifications for optimal operation. Precision stuff is without maps altogether But performance also indicates good efficiency at higher PR.

So far it seems that Garrett stuff has superior efficiency at lower pressure ratios, I.e. where most rotaries live, you can't really go wrong with above, although 57/60 trim would be maxxed out when pushing over 400 HP whereas GT3574 will be operating with almost peak efficiency I.e. with lower compressor discharge temperature and lower backpressure before turbine

Quality of your build and tune will have larger impact on spool up than some perfect sizing, otherwise some odd things can happen, I.e. some guys with GT35R have boost threshold by 2500 rpms and full boost before 4000 rpms, some claim no power at all to 5000 rpms, biggest oddballs are probably hybrids with too big compressor, they start doing something early, but full boost is reached very late, turbo sizing certainly is interesting topic

 

T04e

 

So the GT3574 would be bigger than what I would need. What does everyone see for spool time on the T04E's when running the different divided hot sides 82 vs 1.0 ?

 

talk to elliot i think is his name at turblown. his site is turblown.net nice guy too, he even replied in this thread.

call him and do whatever he says, he knows his chit.

 

You do realize that when you realize you need extra cooling, it may be too late.
You have to make sure all your fuel mods would be able to handle E85 if you're thinking about that route.

I know aux injection is frowned upon in motorsport/organized & sanctioned events (most/some), but realistically it's probably cheaper in the long run to operate WI (or a mix) than to get your car "built" for E85 and tuned. E85 also gets drank much faster (especially since you're using a Wankel motor vs standard reciprocating type).

Nothing a good tune can't take care of though.
Let me know how the G4 RX works out, seriously considering one for my FC. Will you be tuning the motor yourself or 3rd party/friend?

 

Looks like I'm going to run the TD04E, Thank you to everyone for your insights and opinions it's greatly appreciated.

 

Honestly I wouldn't discount water/methanol (WM50) injection out of hand as just a cooling agent. It does a good bit more than just cooling It also helps retard knock and keeps your internals squeeky clean.

Honestly, how often do you see rotors as clean as the one below when an engine is broken down for a rebuild. These are my rotors with WM50 being sprayed, there was zero cleaning done to these rotors before I took the pictures, they're still dripping oil even!



You can see where the side seal **** the bed on mine, which caused the need for this rebuild. Otherwise, you can't really argue with the cleaning properties!

 

Just a quick follow-up to say I ended up going with a Turbo from Elliot (Turblown) and very happy with the purchase. Ended up purchasing a Comp Turbo CT3 with a 58mm Billet cold side with a .84 T4 hotside. Can't wait to see what this turbo will do.

 

I'm glad you're happy. I built one in house with the same turbo last month. I was quite surprised at the power levels for the boost pressure, stock ports, and stock cat.

 

^Sweet looking setup.

 

Keep us updated with your results. Have very similar requirements so keen to hear how it goes. Looking for a responsive torque monster with 400hp if possible. (on e85). Not chasing more than that so rather not fit a 500hp capable turbo and be giving up response.

 

I'm seeing a trend with more customers after a quick-spooling high 300s/400 rwhp setup vs the typical 500+ guys

 

Yeah. Seems a few get hung up on the big numbers. Personally I am an area under the curve guy and like the drivability and a broad power band matched to a nice close ratio gearbox.

 

Unfortunately, most don't realize you can get really close to having both.... AI answers all the riddles.

But of course you know that, and some don't want to worry about another system.

 

^^^ Rules I will be racing under will prevent me from using AI. I can use E85. My experience in piston engines is that can help response a little, and is also nice for some cooling and det resistance. Figuring it helps rotors in a similar way.

So how can I have my cake and eat it too??

 

Run higher pressures on smaller turbos with billet wheels. Depending on who you ask 17-20psi is the limit of pump gas. When you run e85 or AI the cieling rises. You can keep your response AND push the turbos envelope.

 

^^^ Hearing ya. Have been a fan of "more boost" in the past to achieve goals, to a limit though so reliability doesnt suffer. Am running motec M800 ECU so gear dependent/rpm boost control is an option. Tend to set it up to boost hard in the low gears lower RPM to get good punch and taper a little in the high gears high rpm for safety.