I am building turbo kit using a 2008 Fit Sport engine in my 2002 Insight. I just happened to have a Cast Manifold from the HKS RSX kit laying around and set the L15 gasket over the face of it and it looked good so I got out my caliper and got to measuring..... long story short, it will work. the exhaust ports are 1.25" and the K20 ports are 1.75". The step open is abrupt and not ideal but the head ports are in fact completely unobstructed by the ever so slightly offset and re-drilled K20 manifold. Im still a while away from having this running but I figured I throw this out here for those looking for a solution. These are available new for around $200





Build thread-1G Insight w/L15a Fit A/T ultimate commuter - Honda-Tech

 

Very interested to see how this turns out.

I have a few questions, will it bolt right on to the L15A head or are you going to redrill the HKS manifold for that?

And about the ports, are you going to port-match the L15A exhaust port to the HKS ones?
What turbo housing are you going to use?

 

I have in fact redrilled the manifold, I won't be port matching the head as it would be tough to make it with it and this is the biggest compromise vs just building one but worth it for me due to ease, reliability, and cost. Ill be using the Garrett GT2554r turbo.

 

Thanks for the reply, where did you bought that manifold? Does any K series manifold would do the job?

I've been really debating myself whether to turbo the Fit or sell it and buy a Vitz Rs Turbo

 

I bought mine off eBay over 5 years ago, I did a quick google search and found this but cannot suggest the seller, there are a few different people selling them Acura RSX HKS Turbo Exhaust Manifold - Cast Iron

I would assume that this could be done to any manifold but I really don't know. Rev Hard might be a good try, its a top mount T3......



Also I was at the last thread on the two exhaust studs and wanted 5mm more length, found the Nissan GTR studs are perfect and will be using 5 of them.

 

Yeah I found that seller too but can't find any feedback about them. I have most of the parts figured out already, the only thing that is holding me back from turbo-ing the Fit is the turbo manifold (very few/almost none top-notch exhaust shops here in Guatemala) and the high cost it would represent, would take me around 4 years to complete the project because importing parts to Guatemala from around the world is expensive


Meanwhile I'll be looking forward for your build until I can figure out what I'll do.

Daaamn it´s too hard to decide to stay with the Fit, go with the Vitz or the Glanza.

Btw thanks for answering my concerns

 

Great find! So cool to see people experimenting with this. I wonder if this means rsx headers would work too, or the k swap Fit headers for NA, SC, or N2O applications.

 

I don't have an on car pic of it right now but one of the new holes I drilled is rather close to the exhaust runner but a sleeve or a bolt instead of studs will fix it. Also keep in mind the the K20 ports are much larger so there will be a stepped opening but this has be done by the V8 crowd for years. Also I have my engine in a different car so headers will definitely need to be checked. I would say that any header 'should' be able to fit at the flange though.

 

Very interesting. I would love to get my hands on a 1st gen Insight, they are so light!

Do you plan on changing the internals? I see the GT2554 is good for around 270 whp, and the stock L15A tends to brake not much after 200 ft/lbs. I am interested to see your dyno results with this turbo with not only the power band but how early it spools.

 

Loaded questions!! The 'plan' is to run 5-6 psi for a while just to get a feel for the setup, L15s are dime a dozen as are the trannys so in time i will push them both to failure but Id like to get a year out of the originals. I think though that if I can get 150 to the wheels with stock stuff I will stop there. This swap would have been so much easier and done already had I went K20 but I wanted a fun automatic for commuting in. Not only is the K a bolt in affair, but all the stuff you can do, even with oem parts is almost too easy, but another hard part is choosing a turbo....... not a lot about the small stuff online. I was looking at GT2052 which several guys recommended but no one can tell me how GT2052 vs GT2554r compare in regards to spool up..... the smaller is also oil cooled which sounds very convenient (but is it a bad idea?). Its also not ball bearing but will it still spool faster?

 

The step is no big deal, pretty much standard to have 1/8 to 1/4 inch jump especially if your using stepped headers (IE NASCAR) to get the big torque numbers.

I have a couple acquaintances that do big power motors for sprints and midgets and they want the step, supposedly it helps reduce exhaust gas reversion. Both of them claim port matching for a step up junction nets no real improvement and these are NA motors running methanol making over 800 hp out if a 350 chev block, and 400+ HP out of a 2 liter 4 cylinder..

At sub 8psi numbers spool time is negligible on any quality name turbo, you give up a tiny bit off the line but after that its even. Oil cooled turbos are just center sections that only have oil and no water,, lots of engines run years that way and at your boost goals I'd consider water cooling a "nice to have" not a need. That being said, do not run a blanket on the turbo with no water cooling, you want some air around the center section so when you shut down it can cool without baking..
I'd consider a bypass valve setup for a small motor like ours that revs up pretty quick in first in the auto, plus takes a little of the load off the transmission till your rolling.

 

now you got me thinking.... I can go in the opposite direction and go with a T3 50 trim (the small stock one, not T4) that would spool nice and slow and even. This car is purpose built for freeway commuting #1(not racing, not city driving, maybe embracing the laggy turbo IS a wise choice? I have had turbos in my youth but this is all new again, I also had swaps more recently but with K motors in K cars. I have also NEVER messed with an automatic. I have made posts on a few different forums but most answers are very race oriented. In all honesty what drove me to turbocharge in the first place was the fact I have no room for an intake manifold and short is the only way..... If you can make the argument for an NA automatic 2000 pound Insight, Im all ears as I am about to pull the trigger on the turbo. My NA thought were this... My father has been building custom headers since the 70s, I could build a header type intake manifold and I could run a header with 40" primaries ... Cat Cams makes several street cams of which the mild would be my pic if any as I would prefer to have the best MPG possible.

Of all the people I have talk to, few have messed with the Fit. Keep in mind, my wife car is an 08 Fit so I do get to drive it around, its slow.

 

I wouldn't recommend NA to get anywhere near 150 whp. With all bolt ons and a tune you can gain about 20 hp and 30 ft/lbs but that will only put you around the 110 whp mark. I'd go with the ball bearing gt2554. They are rated for 1.4L and up whereas the next bigger size, gt2560 is rated for 1.6L. Both turbos are still bigger than the greddy and HKS turbo kits formerly available which spooled well but maxed out around 220 whp. I'm just arm chair racing with these turbos but on the fiesta 1.6L with gt2560 the boost came on around 3000 rpms and climbed all the way to redline, maxing at 335 whp. I think the 2554 would match the power band of the 1.5 well.

 

......back to the bypass, there is the RDX turbo with the valve thing

 

One of the mysteries I have had in my mind is how the car would shift, Ive had zero opinion until now.... One thing I want is to be able to step on the gas full throttle at any time without worrying about anything breaking besides traction. 110 to the wheels would be about as low as I would want but maybe, thing is I will have flashpro so why not..... The one supercharged fit guy ran 12psi with zero trans issues. (all I have to go from, this one guy) Maybe a 2560 would be a bit softer on the trans? 2854?(bigger turbine) or maybe a journal bearing version of any of them?

 

if you are about to buy a turbo, I would call garret and see what they say.

 

The bypass valve would let the engine start out like its NA, then ramp in the turbo later than a race application. Basically your using a blow off valve backwards, same principle as the bypass valve on a eaton supercharger, The turbo spins up with little resistance then the valve ramps the boost up at the throttle body. Way back HKS sold a whole setup like this for the Mitz Mirage Turbo,,, it made them quite a fun ride and they hardly ever had issues with the engine stress. You might also tighten up the auto by using a different ATF?, something like the old trick shift they used to sell to replace dextron? I haven't run an auto in 30 years that wasn't a track box so kinda out of touch with the street side these days..

 

subscribed cant wait to see the results

 

Any updates?

 

On the manifold its been surfaced and is completely secure, had to use some washers that i trimmed since the new bolt holes are rather close to the runners.

AS far as the car goes Im ditching the auto and installing the gear set from 04 Civic Hybrid into a Fit case for VX/HF style gearing and also installing KPRO (not Flashpro) for E85 etc.