So, I've been doing cross country road trips with my fit almost every year. My car is only 6 years old and I've already obtained 176K miles. Mostly highway miles.

I drive at decently legal high speeds of +80MPH for about 20~30 hours at a time, with just 3~10 minute breaks for gas and restroom breaks. But the car is not stopped for more than that, unless there has been a train accident in Oklahoma, or a blizzard storm causing crashes in New Mexico or Arizona.

My needs are pretty simple, I need to maintain that high speed, even up the Ozana hills of Texas, or the up and down hills of California's highway 152.

I'm tired of downshifting on an automatic transmission.

Yes, I've read these forums. Yes, I've searched on Google. Yes, I've even considered PM'ing DSM. Yes, I've considered a supercharger, but the lack of companies supporting it for my GD3, is sad.

Any suggestions on how to go about this? I'm not looking for something overly powerful, I'm open to upgrading a few other components like the exhaust. I'm currently from Texas, so being CARB legal isn't an issue.

 

Buy a flashpro and have someone make a manifold. From there you could piece together the rest.

 

Sr20det t25. Have someone fab up a manifold, intercooler piping, oil return welded on oil pan, and downpipe.
Buy a flashpro and run 410cc RDX injectors. Fine someone to tune it and you are set.

Would recommend running boost, a/f, and oil pressure gauging.

That is how I will be running a setup for mine.

 

This guy is on the right track

I would really only change from recommending those gauges to making them mandatory.

Here's a really old quick 'n dirty demand chart I made for the SR20 T25:


Also - Trans cooler should be upgraded.

 

I'll do that, where can I get that kind of spool/turbine? I don't know where to get reliable parts. Also, in San Antonio, I'm trying to avoid the 'ricer' tuner. I need someone who can tool/play with the car within reason. I need the car to be reliable at high speeds for very long drive times.

Sr20det t25 = Nissan Garrett s13 SR20DET T25 Turbo Unknown Condition | eBay

NIssan turbo?

Manifold for the exhaust?

This is something I'm looking into doing right away, as I've had the transmission overheat and have the D flashing until I shut off my car for about 15 minutes. This overheat happened in the mountain ranges of Highway 152 in California, near Gilroy CA.

Can I get a write up on how to tap into the transmission system flow to get a radiator to the front. Any suggestions on where to look into this? I also don't know what kind of radiator to get for transmission oil, I don't know if there are different metal compositions for water cooling vs oil cooling.

In other modifications
I've also been tempted in getting a larger fuel cell, but I'm not sure where to go about getting one, and protecting a larger fuel cell from possible damage (since we are limited in space.) Can the rear trunk area be deleted and a supplemental cell be placed there that could bleed into the main one? I don't use my spare tire area, I have an amp there, and a box on top of that to create a trunk in a trunk.

 

Ask and you shall receive (if i'm not busy)

Trans cooler install:
https://www.fitfreak.net/forums/fit-...kevin1107.html

As far as the fuel cell, anything can be done, but I don't know any more than what's appeared in my head as ideas to do this since I read your post, so i'll refrain from commenting

 

That is the exact turbo I was talking about. It has a bigger ar. On the exhaust housing than the old t1r kit so a little higher efficiency.

I believe you just need to add a bigger cooler, possibly with a fan, instead of drilling and tapping the transmission.

Thanks for the chart DSM. I see I was a bit off when mapping mine out at 12psi and above. Good thing I got a evo8 16g with the 10.5 housing for when forged internals come into play.

 

Awesome, thanks.

Back to that turbo, what are the requirements to spool it up? Does it provide power at medium RPMs (2~3Krpm) to maintain a good 80mph with the right torque to prevent the engine from down shifting? I guess I would have to load some weight when I try this turbo.

Is changing turbos a hard thing when I have the exhaust manifold + downpipe laid out? Is it just a bolt on change? Or would I Have to reposition the downpipe + manifold mount points?

I've noticed most if not all turbos have the same layout for bolting things up.

 

Higher efficiency means what? in terms of a turbine.

By bigger cooler, you mean a bigger radiator? Or are you talking about something else?

 

I'm talking about running a bigger transmission cooler.

A higher area ratio housing will allow for more air to flow at a higher rpm creating less back pressure therefore running more efficient. You will have good spool from 2500rpm-7000rpm. According to dsm's chart at 8psi you would make 150-160hp running 100%VE.

DSM I noticed your chart was set for a .48ar t25. The sr20 t25's I have have a .80ar compressor stamping. Would there be a noticeable map shift for the upper end?
http://www.turbobygarrett.com/turbob...1171-3comp.jpg

 

It's a 60 Trim Compressor T25 in a .48A/R Comp Cover, I doubt nearly anyone would tell the difference between a .48A/R cover and a .80A/R on this application.

Comp A/R is not nearly as big a deal as Turbine A/R anyways.

 

I am in San Antonio and am starting my own turbo build. I'm looking for a t25 and have already ordered a flashpro. I am looking for a shop to build a manifold currently. I will let you know and would ask that you do the same.

 

Great to hear!!!


I'm on the NorthEast side. Let me know how it goes.

 

My question now is, can a turbo at the 1900~2200 spool range be possible? I don't need 3K rpm much, except to really pass someone up on 4th or 3rd gear. I want to coast at 75 (which is about 2500RPM) or 85~90 (which is about 3,000 ~3,200 RPM) on highway TX130 (http://en.wikipedia.org/wiki/Texas_State_Highway_130)

So far, the turbo that is suggested here seems to spool up above my coasting RPM speeds, and would only kick in when I downshift into my 3~4K rpm ranges, which would add unneeded down and up shifting to maintain the speeds I'm wanting to coast at.


This will be a daily driver, I don't plan to go over 90mph often to begin with it, that's pushing it on an 85 speed limit highway.


Any other turbos with a lower spool up/power output range?

 

So wait, you all are saying the SR20 t25 is a decent turbo for a stock internal Fit?

If so, I've got 2 of these in the garage, Hmmmm...

 

You only need one Katsumoto and I happen to be looking for one. Let me know if you might want to part with one.

My flashpro is out for delivery it should be here soon

 

@CTE, are you in an orange blaze tinted windows fit on the northeast side? or in a blue fit with a nice roofrack on the north east side?

 

Wish I felt confident about getting this turbo, as the power range is above 2,500RPM and I need power at the 2,000RPM and up... to coast above 60~70mph with load.

 

I'm blue gd3 but on the NW side

 

For what you're asking S/C is the best (though maybe not cheapest) option IMO. What's wrong with the kits that are available? Is it price that's bothering you? Everything is packaged nicely and not a lot of BS to deal with.

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