I'm starting to think no car manufacturer makes the car that I really want.

I'm pretty fascinated by the prospect of using a turbo kit (like the Edelbrock kit for the 6th gen EX) to make real power at the higher end (when you drive it that way), with the stock economy/reliability/smoothness when you don't rev it up.

No car manufacturer makes a car with this goal. They assume if you want a turbo, then you want power all around, so they build the engine (mostly determined by the cams, port size, and stroke) for more performance. That's not my goal. I want to use technology to span the tradeoff gap between economy and performance. No, I don't get the best economy or the best performance. I don't care. But I want to reach into both as much as possible.

So my question, since I buy my car new and keep it for at least 100k miles:

- what do I have to expect with a turbo from a longevity and maintenance standpoint?
- how long do turbos last before needing servicing? and what does that involve?
- does it increase breakdown of the piston rings or any other internals? (compared to just VTECing instead)
- with more mechanical parts and a more complicated system, how much more often does something break? (assuming the same driving conditions if you didn't have the turbo)
- etc?

 

If you buy a new car that has stock forced induction, the motor is built around the turbo/supercharger, so in other words, the compression is different, and the internals are different to withstand the pressure, and other things like hotspots and such.

It sounds like a Subaru WRX would be a good car for you, it is a very nice daily driver and good on gas, and you have the option of many different models and motor size and turbo or no turbo. Also its all wheel drive...

The questions you ask are not specific to a certain car, so they are hard to answer.

- what do I have to expect with a turbo from a longevity and maintenance standpoint?
A- That depends on many things: How much boost you run? How the car is driven? How you drive the car when you drive it?

- how long do turbos last before needing servicing? and what does that involve?
A- On average a turbo will last the life of the motor, as long as you do regular maintenance, and dont run a crazy amount of boost all of the time. Turbos are water/oil or just oil cooled, and heat is the #1 cause of parts failure. So as long as they stay well oil'd/cool'd then it should be fine. After a long peroid of time, you will start to get shaft play, and if you desire, you can get the turbo rebuilt, or buy a new one.

does it increase breakdown of the piston rings or any other internals? (compared to just VTECing instead)
A- That depends on: If it is a stock turbocharged car, or if you add a turbo to a motor that was not designed for forced induction. Also VTECing is not a word, I would recomend doing some research on Honda and (vtec) and finding out what it is befor you get the crap flamed out of you on this forum...

with more mechanical parts and a more complicated system, how much more often does something break? (assuming the same driving conditions if you didn't have the turbo)
A- Again this depends on: If the car comes stock with a turbo, or if you add a turbo to a motor that was not designed for forced induction.

 

Aw F### no... don't tell someone to buy a Subie. All of the most arrogant bastards I've ever met drive those cars.

Truly what you describe is a Saab. The 95 Aero has a variable compression turbocharged engine. It changes its compression ratio as you drive to compensate for variations in weather and road conditions to offer the best of both economy and performance. It packs a substantial amount of horsepower for what the engine is... It can change from 8:1 to 14:1 compression by varying the pitch of the head. Ahead of its time? Maybe. It's a european pseudo-luxury car that's one of the top rated vehicles for safety. Other manufacturers have tried to build an engine like this and got it all wrong.

What you'd pay for the Saab, you could by 10 AWD DSMs for, though. Screw a Subaru. Don't make me post a timeslip of my el cheapo DSM destroying an STi last weekend. ...an STi driven by a cocky bastard that wouldn't even talk to me afterwards... made a point to walk 50 feet from me at all times even as I smiled and waved. Rudest bastard I ever raced. (yes it's personal) $^#@ a Subaru, and their owners.

EDIT: I've shaken the hand of... and congratulated every driver that has ever beaten me at the strip.

 

First off, thanks for the well though out response.

I actually have done my research. I understand that the compression ratio on turbo designed cars is lower to compensate for the turbo to avoid detonation. It also points to why the Edelbrock kit was designed only to blow 6 psi (and requires the 91 octane gas) on the D16Y8 and why the subie blows 15psi at stock.

But I guess I don't know about "hotspots". What are those?

Yeah, the WRX is pretty much top of my list at this point, especially since it also comes as a 4 door hatch. It's just so hard to tear myself away from Honda when it's been so good to me.

I was tryiing to convey a relative comparison. So if a stock Civic is driven normally with hard acceleration sometimes how about if it has a turbo kit (like the edelbrock) with the SAME DRIVING CONDITIONS. Take the Edelbrock kit as an example: 6psi for the D16Y8.

Thanks.

Ok, let's take the Edelbrock kit and the D16Y8 as an example.

Yes, I made that up. People would seriously be sore about a goof term like that?

I thought it would be obvious I was referring to (VETECing =) "accelerating your VTEC equipped Honda engine past the RPM point where VTEC kicks in and uses the more aggressive cam profile"

Ok, let's take the Edelbrock kit and the D16Y8 as an example.

 

It is hard to tell someone how long their engine will last.

It depends on so many variables;maintenance, how hard you drive, how well everything was installed, environment.

The edelbrock kit was designed around a low boost, almost stock system that is trying to retain all the reliability of a stock honda motor. Unless you try to go beyond the capacity of what that kit offers you, you, in most liklihood, will not mess anything up within a few miles.


Nearly every *stock* motor can handle SOME sort of forced induction, it all depends on how high the boost is, compression ratio,and how well the head and bottomend is built to handled the extra power.

Take the subi or evo, they are both built SPECIFICALLY for a turbocharged engine. They have specialized intake manifold runners, exhaust manifold, and a turbo that satisfies the needs that both companies were trying to achieve, a low lag time fast spooling motor that puts out decent horsepower numbers.

As a general rule of thumb, you add ANYTHING that adds more complexity to something, the more likelihood there is for something to break, that is just how the universe works. If you are not a complete idiot and you take care of the motor and turbocharger like how was recommended (more frequent oil changes.. etc) then it will not end up blowing up in your face barely any quicker then a stock honda motors dies, and that is usually a very long time.

In all honesty, Honda motors do not handle boost as well as some other stock cars. Honda power is built around long intake runners, high end power, and high compression to make it all tick, but this is NOT to say that Honda motors are in any means the wrong motor to pick for a boost fiend. I am just trying to emphasize the point that ANYTHING will last, given that it is well engineered, and the person using it is a conscious person and takes the proper precautions (maintenance).



Also..just fyi, hotspots are generally spots in the piston head which are warmer then the rest of the surface area, thus promoting detonation.


Also, another thing... Honda put VTEC there for a reason, using the upper RPM range will typically not promote more wear, its usually the full throttle lower rpm where air is being rammed into the engine by atmospheric pressure that typically harms them. Another example of using engineering how it was built, Honda's were built as high revvers who make alot of highend power for a reason

 

useful replies, so I wont reiterate whats already been said. One very important factor that no one mentioned was the R/S ratio of the motor. The ideal R/S ratio of ANY motor from a longevity perspective is 1.75:1. Honda motors vary, with the B16a being the best at 1.74:1 and the B20b at 1.56:1. The ratio determines the force subjected to the cylinder walls, and piston rings due to the angle-length of the rod-stroke of the crank, in the form of wear. the greater the angle the more the wear.

However, most combinations that swing this ratio dont have alot of torque, so you could see where a longer rod greater stroke would be more suitable to certain apps, like drag racing.

If longevity is a major concern I would be mindful of the R/S ratio of the engine you build. After market rods and pistons are highly recommended.

The other thing that Id like to mention is cooling. factory turbo`d cars have generous cooling built into the water jacket. So that would be another thing to consider.

Im not sure about the engine in your EX. but from a turbo standpoint, I believe you could build a reliable turbo`d car if the entire combination works well together.

 

Since I have the edelbrock kit, I am going to chime in.

If I am on the highway, I get 37-39 mpg as long as the hills are not to bad. In the city I get about 31-33 mpg. I do use 93 octane which is expensive, but worth the reliablity.

If any of you are familiar with cooper's rock outside of morgantown, it is very steep. Unless you get a good run at it at 95-100 mph, you will have to down shift to 4th to get up it. Autos will downshift, no matter what.

With my car, I have to let out the gas at 5 psi to keep from going over 85 mph. It just asks to go faster. This does take some gas, but the extra power is awesome.

I run 8 psi daily and have not had a single problem with it. The turbo spools very fast, and will give you enough power to play around with. I have had it on for about 20 grand now, just getting ready to turn over 100 grand, and no problems at all.

The car is a blast to drive and get around in, and the girls love the bov....

 

That's insane gas mileage for an EX. How can this be possible?

 

Before I put the turbo on I could get 40-41 going through AL, just have to stay out of the gas, and keep it at about 85 mph.

I can still get 420 miles to the tank on a trip, but only if I am not in WV, the turbo loves the hills :grinpimp:

 

Right. I've read in several places that detonation and/or blow by often occurs during low RPM and WOT. (I guess that's due to the relatively slow moving piston and the higher forces from more fuel combustion puts a lot of force on the piston and rings, where the rings are the weaker of the two).

But I'm also concerned with the the piston ring wear at higher RPMs. Higher RPMs simply mean more cycles which means more wear and tear from sliding up and down the walls.

Anyways, please have patience with me. As you can see, I've read up enough to become dangerous to myself but am by no means an expert.... which is why I'm posting threads like this: to learn more and more importantly PUT THE UNDERSTANDING ALL TOGETHER.