i am in the process of choosing a turbo for my custom build...ALOT of options, but i need to know what RPM the pre-built kits are boosting at.

my concern is that my M/T fit is at 3000 RPM in 5th gear at 60MPH. which means i dont want the turbo to spool up much or at all under 3000 RPM otherwise i will constantly be in boost. but being that the fit has a redline of 6500, that only leaves me with 2500 RPM to play with.

so please, if you have a turboed fit, please tell me what turbo your using and what RPM your starting to see boost and full boost is reached.

thank you!

 

Boost is load dependent more than RPM dependent with a small turbo. My t25 CAN be at a full 6 lbs at ~ 2500RPM. However, even during regular acceleration it's very easy to stay in vacuum all the way till redline.

Gas mileage would SUCK if you were in boost at ANY cruise speed...

Think of it this way:
You will be in boost whenever you call upon the engine for a load greater than that of WOT in stock form. When stock, you would just go WOT and be done with it, but with a turbo once you get above a critical RPM you have the option of going further depending on throttle position, gear, and load.


I can stay out of boost indefinitely, even though I spool up at <3k. I never see boost while cruising on the highway at 80mph+ unless I put the hammer down.

I'd say a T25 of a slightly larger trim or A/R would be good for your plans... maybe something a little bigger like a DSM turbo or even a T3. You could go T3/T4 hybrid, but that would flow enough to decimate your bottom end without some work on the pistons/rods, and wastegate-ing it down would be a waste.

 

https://www.fitfreak.net/forums/fit-...t1r-turbo.html

looks like boost starts off idle and full boost by ~3000rpm.(hks and t1r are using the same turbo) but you have to remember boost is only made when there is a load on the engine. as for turbo sizing on a fit. I've done quite a bit of research and right now my top picks are the gt2252, gt2056, and td04h-15g for journal bearing turbos. and the gt2560r (aka gt28r) for a ball bearing option. the 28r is getting on the big side of things. if your wanting a highway queen a .48/.42 50trim t3 would work great. other jy finds that would work well are the ihi rhb5, wrx td04l(high on my charts!), kkk k03(insta boost lol kinda annoying) I'm personally planning to stay with the t25 foot print for expansion capabilities.

I too am building a custom kit and looking to start on it any day now. undecided on turbo choice though. I don't think i'm going to try and market a kit anymore so I'd really like to use my custom hybrid I had built. its a td04hl-15g(big turbine wheel) with a 8.5cm2 divided exhaust housing(3" outlet) and integral bypass valve. I just have to machine the turbine housing for the td04hl wheel. (btw this is a td04hl vs td04l) also td04l is larger than a t25 turbine. ultimate goal is low backpressure fast spool= flat tq with decent hp with low boost.

 

thank you for the responses. excellent explainations.

BTW, i already got a turbo, lol. won it on ebay, its a GARRETT T3 ar.42 intake, ar.48 exhaust.
i couldnt turn it down for the price...so i hope it works well with the L15.

 

that should actually be a decent find depending which compressor it has. some of the volvo .48/.42's came with a dinky 45trim wheel. but if you got a newer volvo or saab unit it should have the 50trim wheel which will support ~250whp. it should still be streetable as well. probably ~500-800rpms higher on spool vs the t25 guys. I would think you can get full boost before 4000.
on a side note you may want to port the wastegate hole larger on that turbo. I put that turbo on a buddies d16 years ago and we had creep issues around 6psi (would go to almost 8psi) ported to slightly smaller than a quarter and it could hold a solid 4.5psi if we wanted it to. oh and don't worry about the cracks. thats normal for them. won't affect performance.

 

pics of the turbo if it helps anyone get any more info....t3 off a saab.

 

NOICE. wish i had the ingenuity to put together a custom turbo kit...probably WAY more cost effective in the end right??? good luck with it and keep us posted, you know the drill

 

definatly. i plan to be around $1300 for the entire build. it helps that my brother is a fabricator and will help me with welding the manifold/IC piping.

manifold parts $100
OIL feed/return $100
IC and pipe $250
couplers $100
wideband af gauge $200
boost gauge $75
OEM honda 310CC injectors $80
turbo $70 shipped
downpipe $75
EMS..undecided. emanage blue $200...ultimate $500

 

Good luck with the build. Keep us posted. Whenever I someday get free time (school is pretty much a full time job, only I'm paying not being paid) I'd like to save some $$ and do a custom turbo build.
Haven't seen too many yet but I know you'll be the first of many to pave the way here!
Pics pics pics are cool!

 

Get the Ultimate. Seriously. It's the best tuning solution we have right now, as there are no P&P options like Hondata. You COULD go AEM EMS, but that's some pretty wicked tuning and costs about as much as your whole setup LOL!

The E-Manage blue CANNOT trim fuel directly, you have to do it through the airflow adjustments (MAP signal scale). However, this doesn't work at idle for our ECUs. So unless you like smelly oil and 10:1 AFRs at idle (cat=toast if you've got one) get the Ultimate!

Also, there are reports that the EMB is very inconsistent with regards to ignition timing. Apparently the computers on board aren't quite fast enough to do all the neccesary predicion calculations consistently, so you get some off the wall timing (some Mitsu Evo guys were reporting spreads of up to 30hp on back-to-back dyno runs when they tried to adjust the timing using the E-Manage Blue and it's timing harness).

Off-the-wall timing + boost + high compression =

 

just a log manifold I assume?
check out just-intercoolers on ebay. can get the ic, piping, couplers, and clamps for ~200ish.
oem honda 310's????
turbo is the 50 trim. should work well.
emanage ultimate or aem fi/c.
looks like a decent setup thus far.
port that wastegate!

 

Good advice. The 310s are only gonna be good for ~200-220 WHP by my estimates. I'd advise 400s if you're serious about putting down the power.

RC injectors are excellent - they're what came with my kit, and they came complete with clips, and a flow report/balance sheet.

 

-yea, log manifold. both kits for this car come with a log manifold...and as it may not be the most efficient type of manifold, it gets the job done. im not trying to sqeeze every last HP out of it.
-i was looking at those intercoolers. it might be the only thing that i get for my kit off ebay..im very skeptical, but beingthat its only an intercooler and pipe...how bad could it be? lol. the only thing im concerned about is how reliable the couplers are. the last thing i want is somthign as small as couplers blowing and causing me trouble when i think im done...
-the honda 310's were on the rsx and new SI...will be perfect for what i want. chances are i will never boost over 200hp, so im not concerned. and they can be found for anywhere $60-80...and local since some people i know with SI's went turbo.
-glad some one could tell me what trim the turbo is...i just saw a good deal did a little research on it and figured i couldnt go wrong for $50+shipping
-did some research on the blue...definatly decided against it. i dotn want any analog adjustments...very innacurate. ultimate it is! probly get one for $300 used if i look hard enough. im staying away from the FIC. many peopel are haivng trouble finding a tuner that can get all teh functions and tune relaibly out of the FIC....emanage ultimate has been around so long that it will be easy to use.

if you have nay links how to port the wastegate, please post them up!

i dont think ill ever go over 200whp with this car...so the OEM 310's will be fine. just FYI, the comptech supercharger in the 06+ SI puts down 240 stock, and 255 with i/h/e using the OEM 310 injectors.

BTW, my goal with this kit is 160-175 whp.

 

i've been buying intercoolers from just-intercoolers for about 3-4 years now. I ran one on my mustang for about a year at 22-26psi with no issues. we also have on in my cousins civic that runs 27psi and a accidental 36psi twice. no leaks at all. i'm very impressed with the quality for the price. and the piping is nice and thick and doesn't distort when tightening the shit out of them with t-bolt clamps. and they have rolled beads on the ends which helps greatly! havent had charge pipes blow off in a looong time. even at sub 2 bar pressures. the couplers are even pretty sturdy.

good info on the 310's. wasn't aware of that. I bought rc's 310's.

oh and on a side note. I'm currently working with vtecfrog on making a extension harness, possibly even with a pre wired sub harness for the aem fi/c or e-manage for those of us who want a plug and play solution or don't want to tap and cut into the factory harness. will keep people updated on that as I get info.

 

FWIW the RC's look a lot cooler than OEMs.. The casing is black aluminum and they've got a cool logo on them, so that's one reason to go with the RCs.

I know, it has nothing to do with how they perform, but I smile every time I see em under my hood

 

im running rsx 310cc right now, pretty much a direct swap..

 

https://www.fitfreak.net/forums/fit-...ss-thread.html

^ my new thread to follow this up.

this can be locked!