Honda Civic Turbo Upgrade.....

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Hey my cuz has a honda civic and wants to hook it up with a turbo kit. From what I no about converting your engine to deal with a turbo you really need to strengthen it up to take all that extra compression. My first question is does a turbo kit come with everything you need to make it happen. And second will just adding the kit without rebuilding areas of the engine lead to a fast streak of break downs and eventually death to your engine?

posted by  cake872

It all depends.

What type of civic does your cousin have?

How much boost is he going to be running?

What condition is the engine in at the moment?

posted by  GreekWarrior

This all depends on who you buy the turbo kit from. Most well known reputable dealers such as HKS will normally package a kit that includes everything that is needed for adding a turbocharger to a N/A engine. However, most all vehicles that do not come from the factory with a turbocharger will require some slight modification and drilling to accompany the appropriate oil and or water lines.

Rest assured that you more than likely will need to source some additional parts for a complete install.


It is highly advised that if you are going to be adding a turbocharger to your engine you should upgrade some engine internals.... i.e. connecting rods and pistons. The stock internals in most Honda engines are just not made to withstand the extra heat and power of a turbocharger. Forged pistons would be a highly recommended item. They are able to withstand more heat than a stock piston

Also in retrospect to your original question, you would also want some sort of fuel controller and upgraded fuel components(injectors, rail, FPR, pump) to properly supply the correct amount of fuel.

These upgrades can range from a simple exhaust and fuel pump to the whole 9 yards depending on exactly how much power you are expecting to push out of the engine. But for the sake of simplicity...

The more boost you plan on making in the engine the more supporting modifications you will need to accommodate the added airflow.

posted by  DSMer

Yea thats what I thought. The civic's year is a 95 for those who were curious and i think its a ex. It is the sports addition thou. I don no how sporty it is apart from it having 2 doors. He cant afford much and doesn't understand to much about the tuning world. Knows mechanic work thou. He did swap out his own engine. I guess the best thing for me to do is make sure he doesn't overdue it on whatever low end turbo he plans to get.

posted by  cake872

Going cheap on engine parts is not a smart idea...ever. to boost my car, im buying another motor, building the internals with connecting rods and new forged pistons (lower compression as well), arp headstuds, and a new headgasket. Then Il be ready to put a mere 10psi on it and feel safe. Putting boost on a stock motor is just not a good idea, especially if you dont have a backup motor. God knows id never put a turbo on my daily driven car and then when it breaks down have to wait to repair it before I can get anywhere again. Also, do not get ebay turbo kits, they are just crap. You get what you pay for, and if he doesnt have much money to spend, this might not be a good idea for him. If he buys a ready made kit, it will cost 2500-3000 generally, and that wont include a bigger exhaust and a stonger clutch. Piecing a kit together should be done only if you know what you are doing and it will be cheaper, but may take longer to get everything you need.

Let me try to expand on this

Lets assume he has 100k on his motor (already too much for boost)
Your "cuz's" civic has a compression ratio of lets assume 9.5:1 like my car (his might be higher)
When you slap a turbo on there, the added pressure is going to start wearing the motor much faster. Decompression pistons for my car drop it from a 9.5:1 to an 8.8:1 which puts less strain on them and makes it ok to turbo. The internals you would replace would now be forged (much stronger and very often lighter), so they would be able to withstand the abuse that a turbo would put on them. Then the same thing goes with rods, they are forged as well, becuase chances are they WILL bend. I wish it was as simple as slapping a turbo on and calling it a day, but its not, and thats why not a lot of people have them because they dont want to go through all of the work to make it happen, and the people that cheap out it ends up costing them more in the long run. With a build and boost, considering he gets deals on this stuff and does it all himself, be prepared to drop around 4k+ on the whole deal. Like I said, if you cant do it right, dont do it at all because its going to be fun for a while, and then once he blows up the motor and cant get to places he needs to be, not only is he losing money on parts, but hes also losing time. Do a bit of reading, and talk to DSMer, he seems to have a better technical grasp on this than I do, im just giving you a broad idea.

posted by  newyorker

Well you guys sure do got it down pack. I figured as much but just wanted to hear it from someone who really knows what he's talking about and maybe has some experience. I thank you guys alot and really appreciate it. I'll have to get back to my cuz and see what he says. By the way check out my post "300zx upgrade advice" if anyone has any ideas. Thanks again

posted by  cake872

Posted in there for ya

posted by  newyorker

This all depends on how well intact the cylinders and rings are. If a compression test shows that he is well in the parameters of the correct pressure range then it would be safe to install a turbo. My car has 140K on the motor and it STILL has the factory cross hatches in the cylinders. Now he's not going to be able to reach 12lbs but he could more than likely run 5-6... Forged internals are expensive and I know how building cars can be on a budget.

By the way, what setup do you have on your civic? How much boost are you running? What fuel management accessories do you have?

posted by  DSMer

Im gona do this backwards. My civic is not turbo, im still in the process of deciding if its a good idea or not to turbo a 115k mile motor. Havent done a compression check yet, but I would still feel really shaky about putting so much pressure on high miles, all cylinder compression aside. Guide me, maybe people are just trying to scare me away from it all. I also cant decide what flange I want to use

The thing is, 5-6psi on a small turbo wouldnt give all that much power, and on a big turbo cause lag. Once you get in between it starts to get epensive. Someone told me to run a gt35r (i think) ball bearing? but said it was in the 600 dollar range for the turbo alone. While I want to make decent numbers with the car, I dont want to put my engine at risk.

The setup I wanted to do originally

t25 cast iron manifold
14g turbo (mitsu one..found out it doesnt even bolt to the t25 flange unless i was once again misinformed)
greddy e-manage
2.5 inch exhaust
2.5 inch downpipe
turbo xs or hks ssq bov
rsx-s or similar injectors (350cc or so)
walbro 255 fuel pump
then id have to run a fuel return line from the rail to the tank because I have a returnless system
stage 2 clutchmasters clutch kit
fridanza 11lb flywheel (heard this would result it something called "chatter")
electronic boost controller
apexi neo
oil lines
blah blah blah you know the deal

It seemed nice at first, but there are just so many things that can go wrong, I dont know if I would feel good dropping 2500-3000 to have everything already installed and tuned, and then blow my little 1.7 liter to bits somewhere down the road

posted by  newyorker

If the thought of a blown engine scares you then you shouldn't be turbocharging your car. Yes there are things you can to to ensure the longevity of your engine but you are "forcing" air into your engine. Realize that when modifying anything you run the risk of damaging or breaking it. It's a simple equation called Performance/Reliability.

As for the flange of your turbo,you're going to have everything custom ordered or fabricated to fit so your choice in flange will be negligible. Just make sure it does match up with the correct flange on your turbo manifold.


When you're discussing turbocharger size you want to keep airflow, or cfm, in mind. A larger turbo will generally push more air at lower boost, but at that low of boost the difference won't be mentionable when compared to a significantly smaller turbo. In high power applications where you can be running in excess of 20lbs of boost a larger turbo is needed to sustain the airflow required to maintain 20+lbs of boost at the higher RPMS. However in a smaller output application where the total output isn't as high a small/medium sized turbo will efficiently sustain 10lbs of boost throughout its targeted RPM range.

Realistically, the choice is all within what your goals are. If you're looking to have a moderately boosted Honda engine running 250HP then it won't take a large turbo. A Garrett GT35R Ball Bearing turbo can run upwards of $1400 and quite frankly thats too large of a turbo for a basic setup. GT35R's are what some of us DSM guys run on our 400-600HP engines that operate at 20-30lbs daily.



Mitsubishi turbos not only have their own unique manifold to turbo bolt pattern but exhaust outlet side of the turbo has a unique 5 bolt pattern that bolts to our downpipes. You could easily have the exhaust and manifold made up to fit.If you're going to get a fuel controller pick between the Apexi Neo or E-Manage. They both do the same thing and you don't need to have both of them. My vote goes for the Apexi Neo. I use the same one and it works well for me.

If you're planning on eventually going bigger(turbo), then a 3" exhaust and downpipe would be the better choice of the two.BOV's are purely a taste selection. Listen to the sounds of one and pick based on that. I have a Greddy RS and its a bit exaggerated for my taste. I've heard HKS's SSQ and I do love their higher pitch staccato sound.

A 255lph fuel pump with 350CC injectors is overkill. 190 will be sufficient even up to 550cc's. Eitherway you will need an AFPRThe flywheel chatter occurs when the pulses of the ignition cycle are no longer absorbed by a heavy flywheel. They can be hear in the transmission at idle. I have an aluminum flywheel and a 6-puck unsprung disc on an ACT 2600 plate. Trust me, the last thing you're going to care about is the sound of your clutch when your clutch is %50-60 heavier than stock. In other words

If you're going to bitch about your car sounding like its been altered from stock .....then don't modify it :mrgreen:

You can always get a manual boost controller. They are fairly cheap and you SHOULD NEVER ALTER YOUR BOOST WITHOUT AN APPROPRIATE BOOST GUAGE. But the choice is always yours. I have a Hallman Pro MBC that is routed from car all the way to a little twisty knob under my dash. I don't even have to pop my hood at the stop light. I can just rotate for a little more boost and "Bye Bye ______ (fill in the blank with the appriate V8, Honda, or Subaru)

Your setup looks good but needs a few tweaks. Mainly your choice of turbo. I've helped a few of my buddy's turbo charge their Preludes and I've seen them use a Turbonettics T04B/TO3 hybrid turbocharger(or something of similar size). They are nice and small enough to fit without having to do major rerouting of stuff in the way. If you are going to rebuild the engine I know its popular with you Honda boys to put in iron cylinder walls.

One thing I didn't notice in your build was a FMIC. No sense in turbo charging if you can't be cool and show it off right? But you can seriously use an eBay FMIC kit. Alot of my guys use them and if they can hold up to 25lbs of boost they can definitely run on a 1.8L Honda. I plan on putting one on myself. SSAutoChrome makes a nice looking one.

posted by  DSMer

Alcohol injection would be another alternative if you wanted a sleeper look.


Also heard from alot of the turbo miata guys that alcohol or water injection is the better choice its just still in its infancy. I dont know why they say that but i thought Id throw it out. I remeber a write up between the two and if IO can find it I'll post it up.

posted by  Enthusiast

I forgot to put the FMIC in there..I was looking for like a 22x5x3 or so sized intercooler, but the thing is for my car, the best setup is the one where the inlet and outlet are on the same side...I cant find an ebay intercooler that size with the holes on the same side..I found a godspeed but it gets larger towards the ends and that would require cutting some shit. Im not really concerned about the sound of the flywheel chatter, but I heard that mechanically its not a good thing. There is a T3/T4 kit out there for my car that makes 185whp and 170 torque on 5psi, and comes with everything needed, including the downpipe, but the kit costs 3000 without injectors, fuel management, etc. It makes that power on a mere 5psi, so I guess that would be better for the motor seeing as its less pressure, but I cant justify spending 3k+ on just the materials. I have a bunch of things that I have to clear up before I go through with this, shoot me an IM on AIM its DJ Driver 88, maybe you can help me out a bit its too confusing to type on here

posted by  newyorker

NewYorker, realistically you shouldn't do anything to your car. 2 weeks ago you wanted to sell your car. Your already tight budget will burst after being saturated with many unplanned additional costs. And you won't be making much more than 200 hp...at the FRONT wheels. Unless you've got a large budget or you are a resourceful engine builder, this will be more pain than pleasure. And if you're paying someone to do the work, your budget is way busted already.

posted by  What

I wouldn't hesitate to boost a 115k mile car. I really wouldn't consider that very high miles anymore either, but thats just me. If your car is beat or has a weakness then ya, don't do it... but with cars lasting over 300,000 miles I wouldn't be afraid of turbocharging with out a rebuild at 115k. Obviously it isn't ideal, but it isn't a biggie imho. Depends largely though on what state your engine is in. If you feel it is worn at 115k, then don't do it. Thats kind of scary though if its messed up so early.

Personally I wouldn't bother turbocharging a FWD car unless I really liked it, any car for that matter. It seems like you are wishy washy on the vehicle. If so, then I wouldn't bother it is only going to be a PITA.

I would agree that a GT25 is about the right size though, any more and its kind of pointless on that chassis. I would simply up the injectors, fuel pump, and lower the compression through a head gasket. Install Megasquirt +FMIC and tune for 91 octane. If you don't have it a good LSD should be the first thing on the list. FWD + 200mm tires + open differential is THE worst. For a car of that weight with RWD and open diff I would want atleast 225's. So now imagine for FWD.

Eventually I want to single turbo the Explorer with a junkyard Holset HX/HY35 and Megasquirt. I could probably do it all for under a grand. More likely $1500, since I don't like to compromise too much, before dyno tuning it. It will be a while though because my project car takes all the funds. Not my daily driver (would suck to break it).

posted by  rudypoochris

Realize though that one turbo kit to another may push the same PSI but they could be forcing way different amounts of air into your motor.

PSI can only exist with a restriction.

5psi wont always make the same power as 5psi with a different kit.

For Example to double your PSI but not gain anything you could reduce the size of the charge pipe by half. The turbo would push the same amount of air but in half the space so PSi would double but you wouldnt see any hp gain.

You should look more at the CFM the turbo and kit a a whole cram into your engine.

posted by  Enthusiast

The size of your intercooler and piping has absolutely nothing to do with PSI or CFM. Only the turbocharger will dictate how mow air will be pushed through the motor. The wastegate will dictate the total boost. There is NO physical way that you could double your boost and not see any "gain" provided you have a sufficient enough fuel supply AND are using the same turbocharger. You clearly lack the knowledge of how forced induction works. Please, do NOT attempt to explain something you don't understand.

To clear that up(as I have stated before):

5psi from two different turbos, more often compared a larger and smaller, will produce different CFM at the same boost setting. Changing the size, direction, length or diameter of the intercooler and piping will only change the way that the air flows to the engine. The setting of your wastegate/boost controller dictates the overall psi of your turbo. If your wastegate is set at 5psi then it will open when the pressure in the engine reaches 5psi preventing the turbo from flowing any more air.

posted by  DSMer

Listen here, boost isnt mesured in the combustion chamber, its measuered in a charge pipe.
PSI stands for Pounds per square inch. Take a certain amount of air and put it into a container. Measure the PSI. Now get a container that is half the size and put the same amount of air into it. Then Measure PSI. The psi in the second container will be higher but there will be the same amount of air. Understand?

And your wrong going from no intercooler to an intercooler can cause a loss in psi as can additional pipe or other modifications to a turbo system.

Compare rear mount and front mount setups and youll see a difference.

posted by  Enthusiast

UGH!:banghead: You really don't have a clue. I will repeat this again and I will make it celar.

EVEN IF MY INTER COOLER WAS 2 CUBIC INCHES, MY CAR WOULD NOT PRODUCE ANY MORE BOOST THAN 18LBS BECAUSE MY WASTE GATE WILL NOT ALLOW THE TURBO TO FLOW ANY MORE AIR THAN WILL PRODUCE 18LBS OF BOOST. YOUR CHARGE PIPE HAS ABSOLUTELY NOTHING TO DO WITH THE TOTAL PSI OF YOUR TURBO SETUP. ONLY THE WAY IN WHICH THE AIR FLOWS



Again. You are referring to HOW the air flows not the total pressure. A larger pipe or "longer" tubes will only change how much air will be needed to produce a said amount of boost. I already know this.

I don't care about pressure loss over a said distance. We are referring to dumbass comment #1:

"For Example to double your PSI but not gain anything you could reduce the size of the charge pipe by half. The turbo would push the same amount of air but in half the space so PSi would double but you wouldnt see any hp gain."

Are you F*CKING stupid? In no way shape or form is that even remotely true. Don't go pop out a dictionary and read some literature and try to attempt to justify your bullshit logic. Its FALSE. Incorrect. Not True...

"Durr if you get a bigger jar and put the same amount of air into it it will decrease the total pressure"

No shit sherlock. Congratulations on your blatantly obvious discovery. Too bad for you an engine isn't a jar. However since your head seams to be empty. How about you fill that with air and test your relative "pressure theories" there.

Imbecile :banghead: .

posted by  DSMer

Where's Hobo when you need him? :laughing:

posted by  jedimario

You don't need the expertise of the Hobo on such a trivial subject. We're not getting into rocket science. This is simple knowledge of turbocharger design and applications.

posted by  DSMer

...it was a joke.

posted by  jedimario

I laughed with you, even if nobody else did, lol.

posted by  Cliffy

It's fairly simple, as long as he runs low boost he should be fine depending on the mileage and wear of the motor before the installation. If the motor is not in top condition, don't do it or your friend will have a 3000 pound paperweight in the driveway (after towing it there, of course). If the motor is in good shape, I would recommend starting really low, 4 lpsi of boost for about 300 miles, step it up to 6 psi for 200 miles and then bump it up to 8 psi and keep it there until a rebuild with stronger valve springs and rods are used with lower compression pistons. But when you go higher boost engine part durability isn't your only worry, because you have to make sure the motor is getting ample fuel. This entails a more powerful fuel pump (I recommend a Walbro 190 or 255 l/ph depending on how much power he really wants to make in the long run), bigger injectors, and some kind of fuel management system and a A/F ratio gauge to monitor it. To much fuel and you'll be wasting alot of fuel and too little and you'll be ruining the motor. As for that fuel management system, I recommend pulling the ECU and replacing it with the amazing MEGASQUIRT system. But some people can have a hard time hooking that up (you could probably find one already built and modified with the Civic ECU harness already wired and some base tunes already programmed on Honda forums somewhere) so a good FMU or piggyback system would fulfill the job. However, you should keep in mind that no matter what parts you replace, the most important aspect to keeping a turbo system healthy is TUNING.

posted by  PontiacFan27

Well I sat him down and gave him a full detailed overview on what he has to do to make this upgrade possible. Its not looking nearly as simple as he was imagining it at first of course. He's gonna sit tight for right now because his motor does have some miles on it and I don think its running at top notch. At least not for a turbo upgrade. So until he can afford to do it right and avoid the paperweight situation the project will have to stay on hold. I thank u guys for helpin me out. I mean I learned a great deal and im sure the hundreds of people out there with honda civics will love this article. Thanks again

posted by  cake872

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