woah! So what did you use exactly? which brands?

 

That torque curve is table top flat for 4k rpms.

A parts list would be nice.

 

check my thread under photos+videos, but its a top fuel zero 1000 sri, megan test pipe, and hks axle back. 93 octane, everything else is stock as a rock.

 

oh its only the beginning. was just getting a baseline of the kit before i get more boost. im gonna get rid of the emanage and get an aem f/ic then next is to get the greddy electronic boost controller. i have 320 injectors and i think they said they were only 50%. i got a lot of room to play. greddy adjusted the prototype to 8psi and thats what the guy is still running at.

 

The AEM F/IC appears to be the way to go, but I still think you would be better off with a manual boost controller vs electronic or spring pressure.

You'll find it is more straightforward, easier install, and you're only running maybe 8-10psi max for the foreseeable future and the money could be better spent elsewhere.

Alot of higher boost guys, like 25+ psi are switching back to manual boost controllers as well, except for the full AEM standalone and DSMLink guys, because we now have the option to use our stock FPS or EGR solenoids to control boost by speed and gear.

 

Those are decent numbers...I really would like to see n/a numbers, that way the car retains it's reliability, the fit is really a great handling car right out the box. I can honestly say it handles ten times better than my 98 trans am and handles better than the 350z I had

 

That is why I am keeping the L15A for my project and not putting a big heavy k-series in front of the shock towers/axles. Putting a 20lb turbo behind the engine and like 12lbs of charge piping and IC on the front helps maintain that plus potential for lots of power and torque.

Though, I'd like to see some evidence to support the idea that somehow a turbo makes the car less reliable.

 

The dyno readout looks like it was for a CVT model.

 

The unreliable claims come form the fact you throwing boost at a car that was originally N/A. The boost is just putting more stress on the engine and theres more potential for things to break. With a proper tune and the extra maintenance the car needs, it can be just about as reliable as and car.

 

You realize that seems to be a contradiction you've just posted, though I agree with the latter part of the statement.

Genuinely curious since there was no data presented... what besides a bolt-on kraftwerks kit have you done to an engine that would leave you with the experience to make that first allegation?

Do you tear down to look at your bores and bearings routinely? Can you read bearing wear? Do you know how to adjust tolerances for different applications on the same motor? Have you ever bent a rod? Melted a piston or valve?

Do you plastigage, mic and blue print everything you build?

Explain how cylinder pressure generated by a turbo is any different than cylinder pressure generated by a balls-to-the-wall all-motor build? Or running straight alcohol?

I'm not talking about pressure spiking caused by NOS I am talking about consistent airflow.

Is an extra couple charge pipes and oil line, maybe a coolant line, that much extra to tend to over the already intricate engine?

On a good tune there is no reason to suspect excess wear with forced induction unless you are not doing the maintenance and inspection you should have in the first place. When most Fit owners talk turbo, they are discussing maybe .8bar of boost. I intend to maybe see 1bar on a 405cfm turbo.

That is hardly asking that much considering there is already engineered in extra safety margins to deal with things like persistent knock from the various shitty fuels L15A encounter throughout the markets they are sold in.

PreDet pressure spikes, which some of these cars see routinely for their whole service life, are far more detrimental than some extra air. The engine is just a pump, it doesn't know any better.

What gives you the confidence to throw a statement like that out there? Engines fail for lots of reasons, including NA builds. As you said at the end of your post, it's all in the tune. What makes a good tune is up for debate on any given platform and parts combination though.

Making absolute sweeping universal statements like turbo=bad for longevity is foolish.

You realize repeated high rpm thrashing in order to get to the fat part of the power band in a small NA will do more damage than some extra airflow at lower rpm, not too mention a more streetable car with power available sooner.

 

Im not saying turbo is unreliable, I know several turbo Hondas that are daily driven. Turbo, Supercharger, NA, Nitrous any those builds when you start adding significantly more power to the car you run the RISK of breaking a OEM parts. You seem to know alot more about all this though so I guess dont listen to a damn thing I say.

If you need a example of my claims that boost CAN be unreliable. There is a Civic on a local forum his car puts out 477 whp at the start of the year. This year he has had nothing but trouble with the car. He has broken several transmissions, broke a urethane engine mount. After he gets every thing together and running the same day he cracks a sleeve. Gets a new bare block, has it machined and what ever else to it, starts it up and is only running on three cylinders. Traces the problem back to the injectors and has them bench flowed, they where all over the place.


last bit of his post
Thats just a example of the potential problems you COULD have when adding boost or any engine mods.

 

Sorry if I came across as a dick.

Everything has limits, finding them and taking a step or two backwards is the trick.

Boost and Nitrous are completely different animals that can accomplish the same thing but through different processes. Can you use both reliably? Yes.

I have lots of faith in OE parts from most companies, mostly because they have gone through countless hours of R&D and stress testing with ridiculous funding and are damn near always built way tougher than they have to be.

Am I saying you could throw say a GT37R on your Fit and expect long term success? No. Not to suggest it's impossible or necessarily a bad idea, but if you are going to boost an NA you need to find a balance you are comfortable with.

Would I run 15+ psi on even a 405cfm 14B turbo on my Fit? Maybe. Would I consequently have to pull the oil pan and rotating assembly every 10-20K miles? No, but it would be a great idea.

When I pulled bearings out of one of my 4G63s after 3500miles of hard break-in to see how the new aline honed mains and rod journals were doing, , the bearings practically looked polished like the moment that I received them from ACL. This was when I swapped out the 14b for a bigger snail, it had been seeing ~18-19psi daily the whole time, which is more than twice the boost it came set up for from the factory.

Then 5000 miles later on the bigger turbo at higher boost, when an 18 year old t-belt tensioner I pulled out of a 129k stock long block took a crap on me and the tear down inspection began, the bearings had no perceivable galling or scoring, and still looked practically new. When I do it again in 11,500 miles or so (20K total) I expect them to be only slight worse off.

EDIT: I should point out that I am referring to a non-turbo 4G63 that I turbo'd because I got the entire long block for $40 from a gas station in palatine that thought it was blown. I did add an extra large external oil cooler to help the NA motor with its lack of piston squirters, because the oil is flowing through and out of the exhaust side (hotter side) of the cylinder head before entering the turbo and being dropped right back into the pan. I intend to help the Fit in this fashion as well.

 

No worries, tones can be lost in text. You do though seem to know alot more about all this then I do, im very new to boost and even this level of modifications to a engine.

It does seem though, that we both agree that a boosted car can be reliable as long as you know its limits. I just might not be doing a very good job of explaining my points.

 

To be a nit picky asshole... that was a fuel issue not a turbo issue

The transmissions and motor mount sound like him using that new found torque whenever possible and the cracked sleeve sounds like his PTW clearances were too tight for high boost, high rev, and high heat. I don't know what his options for built transmissions are, but in the mean time he may want to get an aluminum front roll mount, and a prothane on the firewall side. I have a feeling banging home shifts and wheelspin were the perpetrators of the trans carnage...

Has he tried L19 head studs and an MLS or O-rings? I have run regular Fel-Pro composites into the 30psi range on standard 12mm ARP studs torqued to 105lb-ft, and yet to lift a head.

However when or if I do reach the threshold, I will lose the engine if the studs or gasket don't yield. Which is my only reservation to MLS gaskets. They are definitely tougher but I use HGs as a fuse.

 

It definitely seems we are in agreement

 

The real problem is that once you start seeing how easy it is to turn the boost up and make more power, the possibilities become endless and that's when things break. It is hard to know limits when the speed bug bites.

 

Very true. Was harder when I was a teenager, though. Not too far removed from that, unfortunately. Occasionally still melt or blow something up. Great way to learn, but very expensive and time consuming.