i've an automatic honda fit 09 with hks turbo... please help to make this car runs about 250 hp... i just got 155hp with 0.3 boost..i want a higher boost level but i'm afraid my engine will blow..so i need to replace my old piston and rods.. anyone can help me to choose the right forged piston and connecting rods?? please give me some feedback,,

 

You need a slightly larger turbo GT28 or an MHI TD05H 14B or 16G to do it safely, larger fuel injectors (RDX 410cc/min) a larger or second external pump, a methanol injection kit and some way to tune all that..

You have a GE8, you already have forged con rods. If you use meth injection and a larger compressor you will be able to get away with it.

I assume you are talking about 250whp? I would aim for 200whp first and see where you end up.

If you insist you need sturdier pistons give Wiseco or Mahle a call! They have both served me well in the past. They should have off the shelf pistons, and if they don't they will make any piston you ask for and are usually very competitive with pricing.

 

thank you for replied my question..
ohh i already have forged cond rods? yes... but it's not strong enough man...
not 250 whp but 250 in fly wheel it abouts 200 whp less..
wohhh wiseco or mahle.... how about cp?
i've added extrainjector on intake.. and should i replace the oem injector with the bigger one?
and the turbine that i have is garret T25 but proven by hks..

 

250 Crank HP is going to be 200-215whp. I know CP makes L15A pistons, but I recommend Mahle and Wiseco, CP will work for your needs as well.

The factory forged conrods are not going to be a weak point, as FF member Lyon has proved through many 55shot nitrous backfires, which generate far more cylinder pressure than 200whp requires from a 1.5L.

You have the stock 185cc/min injectors in the car currently?

What size injector do you have in the intake tract? What fuel(s) are you injecting? How are you tuning all your injectors?


If you insist on keeping the HKS GT2554R to make 200whp, you should over build your supporting systems.

Boost is addictive, remember your Fit will have about 210-215lb-ft of torque to go with your 200whp on that 53.8mm exducer turbine. You will want to go bigger.

If you are going through the time, effort and expense to bulk up your rotating assembly, you better put an overkill fuel system in as well. 440cc/min Acura RDX Turbo injectors, an external in-series fuel pump like a walbro, some bigger fuel lines, high flow filter, adjustable fuel pressure regulator and -6AN or -8AN fittings with rail/tank adapters.

When you finally make your 200whp, you will want more. If you already have supporting mods that exceed your next set of goals all you will need is an AEM FIC or better, and a larger turbo..

Which can be as easy as swapping out parts of your GT25 compressor for GT28 compressor and compressor housing, they use the same CHRA after all!

With a marginally bigger, more efficient compressor it will be friendlier for pump gas, providing cooler charge temps = less knock = safer and more reliable in the long term.

Then 250whp is only a couple turns on the boost controller and some tuning pulls on a nice secluded piece of highway!

It took only 330whp/350lb-ft to put my other car, which is very similar to the Fit (2500lb FWD 5speed manual) into mid 12 sec quarter miles (Which is actually depressingly average and slow in the DSM world )

250whp manual trans Fit with a good driver and some nice tires could be a high 13sec car. That is about what stock Evo X's and modded STi's run in the 1/4 mile!

 

Great info DSM..... Does anyone know what kind of H.P. his automatic tranny can withstand?