I see lots of HKS bolt on kits that are made for the ge8. But whats the maximum boost you can give the Fit before it chokes and pops?

 

Made for non-USDM RHD GEs...

No engine has a boost limit. Its the rest of the equation that matters.

If I wanted I could "pop" your motor @ 3psi, or it could survive daily duty north of 20psi.

If you are serious about turbocharging the car, avoid "kits" with a one size fits all tune.

 

Most jaanese cars will handle 10 psi when done correctly and not severely reduce reliability. The problem is 'done correctly' that matters.

if your Fit is not a unnecessity toy, leave the engine naturally aspirated.

 

"Most japanese cars will handle 10psi" - I definitely wouldn't have expected you of all people to believe something like that

10psi by its' self doesn't really mean anything. That number is merely a measure of restriction, what couldn't fit into the head and was crammed up against the intake valves.

It doesn't account for fuel quality, IATs, compressor efficiency, Turbine Phi ratio and drive pressure, charge cooler efficiency, spark angle advance, lambda, etc.

10psi, 0* peak timing, and 9.5:1AFR would run like a complete dog. 10psi, 27* peak timing, and 13.5:1AFR would probably melt hardware or lift the head.

 

I've seen alot of people say if you just get a universal kit for the fit it can handle 10 psi and under untuned. but Like you said I don't want that gnarly of an AFR and blow/pop/melt something. My fit is my daily driver and I do not want to incapacitate it again.

 

DSM explained it very well; the PSI is really just a measure of restriction. What you're measuring with PSI is just manifold pressure; it doesn't give you the whole story. How efficiently your engine is using the increased pressure is more important than the pressure itself.

I used to have an EP3 Civic Si with a supercharger. That kit uses a positive displacement, roots-type blower. It's a good kit, but the blower itself was crammed right up against the head, for the most part. The manifold was very short, and the blower spun relatively fast, near it's maximum rated RPM, in fact. At that particular blower speed it would produce 8.5 psi of pressure in the manifold. It made good power, and when tuned well would make about 230-240 wheel horsepower. With a race header or high-flow cat and good exhaust, you would actually see the boost pressure decrease, but your power would increase. Say what?! That's because more of the air that was making that pressure in the manifold was now able to get into the combustion chamber where it will actually do some good. This is a good example of psi not telling you what's really going on.

On the flip side of that coin, look at the turbo numbers for engines running very similar boost pressures. Those guys are near 300 whp (k20A3) and making a boatload more torque. All on the same boost pressure. Why? For one, they could run an intercooler, and that's only a small part of the equation. The supercharger spun so fast and the manifold was so small that the boost that it did make was just saturated with heat.

I'm not saying the supercharger didn't make the car fast; on the contrary it was much faster than stock. The turbocharged guys, though, were making much more power and were just as reliable. Tuning is the key. It becomes more important to do regular checks of your fittings and oil when you make these sorts of modifications, but done right you'll have years of reliable driving. I drove that Civic for 60k+ supercharged miles with little other than needing new plugs a few times (running a little rich from a "one size fits all tune") and changing the blower oil (takes 10 minutes - tops). I sold the car nearly 3 years ago and it was still running like a top, even if it was a bit on the rich side.

I haven't been around here too terribly long, but when it comes to engine work, especially forced induction, and based on my past experience with other cars, DSM knows what he's talking about; far more than I do, I have no doubt.

 

Well 20 boost inches is 10 PSI right? I was going to get the kit with the nice wide intercooler and should I get a root or ball bearings? I know the turbos get hot especially with hondas cuz they face towards the radiator and thats no bueno! I would have to get a heat shield or wrap it up and impliment the intercooler as well.

 

WTF IS A BOOST INCH?

OP, do you know ANYTHING about cars?

 

I'm going to take a stab here...

Do you mean inches of mercury? It's just another measurement of pressure: 20 inches of mercury (inHg) = about 9.8 pounds per square inch (psi). I don't know where that comes into the conversation, though, as it hasn't been mentioned.

What do you mean "root or ball bearings?" I think you're confusing two different things here. On a very technical level, a turbo is a specific type of supercharger, but they really are very different. A non-turbo supercharger - be it roots-type, twin-screw, or centrifugal - is tied to crank speed by a belt. This is very different than a turbocharger, which is fed by exhaust. When people are talking about ball-bearings in regards to forced-induction, they are generally talking about turbochargers. There is no option to choose from between roots or ball bearing unless you are actually asking whether or not you should go supercharger or turbocharger. You're the only one who can answer that question. There have been endless threads all across the internet debating that very question.

In the Fit, the turbo would not be near the radiator. The exhaust exits at the rear of the engine; the radiator is at the very front of the engine compartment.

Orcshine, it sounds like this is very new to you, and I don't want to sound like a jerk here. I say this with all sincerity: Read, research, and even witness, if possible, all you can about how these modifications work long before you dive into something that can become very expensive if done improperly. The cost of any forced-induction kit or parts are only the tip of the iceberg for a well-running setup.

 

Sorry OP.

Like I said in your other thread with the same name, search all [Lyon]Nightroad and DiamondStarMonsters threads.

 

No you don't sound like a jerk or troll, I am VERY new to the turbo world. I learned about it last semester in my engines and machining class. me and a team of students deconstructed one but I have yet to apply forced induction to an everyday economy vehicle and test it on a Dyno and test for numbers.

I appreciate the feedback from someone I assume that actually knows wtf they are talking about. I am just thinking too many steps ahead for my plan. Like I said before I love my GE8 and it is my daily driver so if I do mod her I will want to plan it out before I do so.

Yeah it does seem like I am getting the two confused. Superchargers run off the crankshaft and turbos are powered by the exhaust creating a negative pressure. I like how the turbo isn't a "on all the time" deal so there is no mechanical sacrifice there. I know I will need a larger diameter exhaust manifold and system. 80mm+ diameter?

Its just whenever I hear an STI go by or my classmate with his NSX..... go by I always envy their boost and it satisfies the drivers with the lead foot

 

I make up my own automotive physics.

 

Is your classmate's NSX modded? If not.....those car's aren't turbo. Or supercharged.

 

I would go very easy with this type of engine since it is not really made for performance. I supercharged a Civic with 10psi, 0* peak spark timing, low temp NSK spark plug, 92 Octane gas. It runs well, but not as much additional horse power as advertised by the supercharger kits. Even with this moderate mod, the head gasket cracked at about 100k after the mod. Again, I would not push too hard on the engine.

 

So 100k miles, no tune and then the headgasket goes, you think that's bad? My head gasket went out in a STOCK car at 70k miles. You dumb, fo real.

 

lolwut


tenchar

 

This thread is fail, but OP at least your asking before you act.

 

so I'll just get one of those vortex fans instead. *scoffs*