ramboPandA

Hey i have a b18c5, that i spun a bearing. So i sleeved it out to 85mm and 10:1 pistons. I want a hp goal of around 250-300. A little less than 250 is fine though if anything. I know the block can handle it. This is my first turbo car, so i want to go easy at first then go bigger later on. And the block can handle a lot.

What kind of turbo would be good for that kind of HP goal. This is my first turbo build so i want to take it easy at first. Was thinking a t25 turbo? But dont know what kind and what brand. Not looking to spend crazy amount of money.

And what would be a budget friendly manifold?

Any other opionins please.

NotARaCist

iTrader: (1)

Why would you lower your compression...ugh. Stop doing that, people!

Disco Potato. Simple cast manifold. Why you would sleeve and build any B series, especially an ITR, and only have a goal of 300 WHP is beyond me though.

ramboPandA

Well technically the CR i did the calculator thing is actually higher tha 10:1 because it was the flat top pistons. And the only reason im aiming lower is because i dont want to turbo, go big and run into problems.

and what is a disco potato lol.

ramboPandA

and i have hondata s300

ramboPandA

bump

ramboPandA

Or should i just get a t3. Was thing about the GT28RS

NotARaCist

iTrader: (1)

Holy ****, it's been less than 30 minutes since you created the thread. We aren't getting paid to sit around and answer all of your questions. Be patient. While you're being patient, use Google (if you had, you'd know what a disco potato was), and read the FAQ sticky in this section (if you had done that, you'd know why low CR is dumb).

Dallasb84

Nailed it.

ramboPandA

Ok. And last time i read 10:1 was not considered low. And to your other statement before. I said i didnt want to go like 400+ because that is when it becomes unreliable. So i was just going to stick to around 300 to keep it daily able.

NotARaCist

iTrader: (1)

You have a LOT of learning to do. Go read the FAQ sticky. Then go read it again. Go to sleep. Print it out, and read it with breakfast. Listen to it on audio tape while you drive to work. Read it during your lunch break. Flip the audio tape over for your drive home. Grab a drink, read it one more time, then, if your questions aren't answered, and your misconceptions aren't corrected, you'll be ready to start understanding things.

It might sound like I'm being harsh, but FI systems aren't "easy". There's a lot more to it than "let's bolt some parts together and go fast!" If you don't have even a basic understanding of what's going on, and just trust random strangers on the internet to tell you what to do, you'll end up with a suboptimal car, an empty bank account, and a sad feeling in your pants every time someone who did their research pulls on you.

NotARaCist

iTrader: (1)

Misconception #1: Lower static compression ratios are better for boost.
Correction: The only limit to your static compression ratio is the fuel you want to use. 93 AKI has been used by many people successfully running high boost, 11:1 (and higher) CR engines. E85 can go even higher. Higher static CR means more power out of boost, meaning a better power curve. Lower compression was a "thing" back in the early days of Honda FI, because the only actual tuning options available were restrictively expensive, so people were using FMU hacks, which had an extremely limited resolution - you couldn't be picky with your tuning. Lower static CRs gives a higher detonation threshold, allowing you to "safely" run an FMU hack without worrying about detonation. With the hardware and software available now, at extremely affordable prices, there's no reason to go lower compression. You can get a proper tune, down to whatever RPM increment you need, to prevent detonation and build a powerhouse of an engine.

Misconception #2: Anything above X WHP/BHP is unreliable
Correction: The only limit to reliability is in the quality of parts used, quality of assembly, and quality of the tune. A stock B series engine can safely and easily run 300 BHP without problems. Upgrade to a forged rotating assembly (pistons and rods), and that number goes to 400. Upgrade your sleeves, and the sky becomes the limit, with the right parts. Depending on fuel used, and the quality of the tune, you can get even more than that out of them.

turbohatch96y7

iTrader: (15)

Dont listen to notarascist hes ******* racist

wantboost

iTrader: (2)

Wait did you take the stock sleeves to 85mm or was the block sleeved? With that much displacement had you gone high compression NA you could've gave made over 250. The main problem with a bore that large is if anything happens that damages the cylinder walls you can't reuse the block, you'd have to get another sleeved again.

You don't need an old t3 based turbo to make the power you want. Also the turbo is terribly inefficient compared to the turbo technology today and it will be slow to respond compared to the turbos we have today.

A gt2860r, gt28r (gt2560r), gt28rs, gt2871r, gtx2867r, or even a BorgWarner EFR 7163 (my personal choice) would all make the power you want and give you an amazingly responsive, very broad power curve with a very large flat torque curve. Since I'm assuming this is solely a street car that's the kind of power curve you want. Makes the car much more enjoyable at normal surface street speeds.

The Garrett gt28 family uses an internally wastegated t25 turbine housing standard but there are t3 options available to a few of them, however, due to the differences in the center section (also called the CHRA or cartridge) the gt28r and gt2860r are only available with an internally wastegated t25 turbine housing.


The BorgWarner EFR 7163 is offered in either an internally wastegated t25 housing or an externally wastegated vband inlet housing in two a/r sizes. However for a fee Full-Race will cut the vband inlet off and weld on either a t25 or t3 inlet flange.

Most manufacturers of Honda turbo manifolds don't really make "shelf" manifolds with a t25 flange but they could make one using a "standard" manifold they offer if there isn't any major reworking of the manifold. The only company I know of that made one as a regular offering was Neukin but his shop burned down last year or the year before and I don't think he reopened, I got one of his last t25 manifolds. Other option is to have one made.

However there are t3 flanged turbine housings available that fit the gt28rs and larger gt/gtx28 turbos like shown below. If you order the turbo from ATP then you'll have these housings as an option at checkout.

T31 V-band Exhaust housing for GT 28RS through GT35R or GTX30/GTX35 : atpturbo.com

T31 Turbine Housing for GT28RS / GT2871R/GT2876R / GTX28 : atpturbo.com

Of course turbo selection depends on if you are going to want more power down the road and just how much.

The gt28rs or "Disco Potato" is good for around 275-300 before it becomes inefficient

The gt2860r is good for about 300-325

The gt2871r will make around 425 maximum due to the flow limits of the turbine wheel.

The gtx2867r Is also good to around 430 but is more efficient doing so.

The EFR 7163 has a compressor wheel that flows 60lb/min however due to turbine wheel size you'll never reach the limit. So far the turbo has made 535hp on a 2.5l STi using e85 and it only spools a few hundred rpm slower than the stock vf39

Of course cost is the biggest deciding factor. The EFR is the most expensive, starting at 1800 and depending on options can touch 2400. However you get a complete turbo with a built in blow off valve, boost control solenoid, provisions for a shaft speed sensor, etc. Plus you're getting the most advanced turbocharger technology available to the public today in a nice clean package. Maybe I'm biased though lol.

The Garrett turbos can be found affordably in good used condition or you can buy new.

The gtx2867r runs around 1400 without a turbine housing and depending on what housing you want you can pay up to another 400 dollars for it.

The gt28 series starts around 900 dollars up to about 1300 for the 2871r

End of long *** book lol. Hopefully this helps you out a bit.