Would that work? I don't see why not it's for 1.4-2.5l engines.

Engines at 8.5:1 compression eagle/wiseco rod piston combo.

 

8.5:1? Are you crazy? That's stupidly low. Yes, if you searched and read in the FI section, you would know that the disco potato is a great turbo for these motors.

 

He would be able to make crazy high boost at high rpms without any problems ever. yakno, where our EGs/EKs normally make their power.

but I know, its just so hard to down shift that you need to make torque out of a 99 cubic inch engine at 2,000rpms. Forget making 500hp at 9,100 rpms, thats so 80s

 

ron, you need to do some more learning before you put finger to key. In non-forged (read: OEM) applications, lowering the compression ratio lowers the detonation threshold, making the car easier to tune. Easier to tune also translates to more reliable. Back in the 90s, when the best thing we had access to was stupid VAFCs and FMU hacks, low detonation thresholds were important - there was no fine tuning, so keeping the engine from detonating was very important. That is the ENTIRE purpose of lowing compression.

Today, we live in the age of this great thing called technology. There are plenty of engine management options that offer real-time logging, and fine tuning down to the hair, so you don't need low compression. in fact, you can RAISE compression, slap a turbo on there, and still make amazing power, especially with forged internals. The norm nowadays (at least, for people who aren't stuck in the 90's), is 10.5:1 or more. You still get the same final power, but you get a MUCH better powerband, because you actually have power outside of boost. When you lower your compression ratio, you lose power. Period. If you want a car that isn't a gutless piece of trash, that means you have to run a smaller turbo, so that a quicker spool can make up for the lack of power. A smaller turbo means a lower top-end. With the higher compression ratios allowed by better engine management options (and better fuel, too), you can get more power outside of boost, which means you can run a larger turbo that would kick in a little later, which means you can get more power in boost, too.

You're welcome.

 

So I should go for a Higher Compression ratio?

 

If you don't mind ripping apart the block again to replace the pistons, then yes, I definitely would. Stock on that motor is 9.6:1. With forged internals, I would definitely go 10:1, if not 10.5:1, assuming you have a competent tuner.

 

8.5:1 is just senselessly low. You're going to end up with a motor that lacks any sort of thermal efficiency. You'll have **** poor power and throttle response when not in boost not to mention a sizeable decrease in fuel economy over a higher compression motor.

It makes a little bit of sense if you're going for some ungodly amount of power and don't have access to decent fuel or a decent tuner but people are making close to 500hp on motors with compression ratios as high as 12.5:1 on 93 and as high as 13.5:1 on e85 making well close to 800hp.

This is the age of highly capable electronics and chemically advanced fuels, take advantage of it.

As an example one of my current projects is a 10.2:1 static compression stock internal motor that will make an uber responsive 300-350 on pump gas. I'm building a stop-gap motor for my civic that will be 10.5:1-11:1 and make close to 500hp on 93 while I build a bigger 12.5:1 motor that will make the same power but have a much broader powerband while making a lot more torque.

Don't be afraid to push it... If it breaks you simply rebuild it and learn something new and what not to do.

 

And above all else, make sure you trust your tuner with your life. That's the ************ who decides if your motor lives or dies, and how long of a life it will see.

 

GTX2860R is a fantastic little turbo but do you really want to spend that much for a D series? The turbo would be worth more than the entire engine + car.

 

And it'll still flow just fine for a B series if he decides to swap in the future. And it'll be a LOT more reliable than whatever cheap eBay **** he could be looking at. Do it once, do it right, and be done with it. OP's on the right track.

 

Too low compression ends up exploiting other inefficiencies in the system. As you begin to think that 8.5:1 will be friendly with low octane fuel and much safer, you will quickly realize that a GT28 turbine ends up losing efficiency beyond 18 PSI.

It's a trade off, and with a small turbo, the turbo's inefficiency may end up surpassing the compression difference. This is speaking of peak power under boost, and not counting other drawbacks like lack of throttle response, higher BSFC, and very sluggish out of boost and building boost.

8.5:1 is a poor choice of compression for a car looking for roughly 280-300 WHP on a 1.6L with premium gas (91/93/94 oct).

If you are looking to tune this car yourself, or assuming the tune may not be as good for whatever reason, then I would choose something along the lines of 9.2 to 9.5:1 CR .

 

Alright thanks for the input everyone.

I'll be getting my car tuned by Matt Shue who's apparently the best guy In Virginia when it comes to tuning Hondas.

 

You guys are great at exaggerating. 8.5:1 isnt going to be some gutless motor with poor fuel economy that is a complete waste.

How many thousand vitara setups are out there before they started making custom length rods. My vitara/eagle d16 not vtec is probably somewhere in the 7.5:1 area and has zero trouble getting around town out of boost, theres days on my commute I dont go into boost and still zip around and pass cars easily. I also get 38-40mpg....

8.5:1 isnt the end of the world

 

It's not the end of the world but it's far from ideal and optimal.

Once you've driven even an na high compression motor and then drive a low compression version you'll really be able to appreciate the difference between the two. Granted your average person would never really notice the difference, especially if they aren't driving in a competitive environment.

 

Not apparently, he pretty much is. There are rare few other options as good as he is.

 

Tuning is the problem I'm having. There's only one decent Honda tuner in Georgia and everyone has said if you're doing something like a high power high compression turbo build then go somewhere else.

So my only option is to trailer the car out of state.

Louisiana, North Carolina, and Pennsylvania to be exact.

 

Bring it up here, wantboost. We could get drinks, maybe take a trip down to VIR afterwards! There's also BMo up in Maryland, if you want to make the trip even further

Shue does travel, though, so it might be worth calling him and seeing what's up there. I don't know if it's a "you pay my airfare" kind of deal, or a "if I'm in the area" thing.