Festy dyno vid 302 hp

[Advancedynamix]

Nobody likes no downpipe. B rad is right, you need a down pipe! Lol

[Flyin4stroke]

I'm trying to start the new yr off right.

[bhazard]

Don't need no downpipe

[Flyin4stroke]

Festy dyno vid 302 hp

Yes. The turbo is on the car but I have to get my downpipe flange and make a dp. I have all the pieces. Also I have to move my intercooler piping but I have the pieces for that too. And add wastegate to another manifold I had. Also getting a civic rad so it's getting welded.

Fingers crossed I want to go Sunday to the track.

[bhazard]

Okay Mike, any updates? I'm kinda anxious lol

[bhearts]

^ Why? I mean why run a pipe that long if you don't have to? If you just want a dedicated pipe, a short dump should be sufficient.

Just curious. Not hating.

I think it had something to do with not disturbing the post turbo exhaust flow

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[Dragonhealer]

^ Why? I mean why run a pipe that long if you don't have to? If you just want a dedicated pipe, a short dump should be sufficient.

Just curious. Not hating.

A short dump (43" avg) would be best. bharts wants super cool, we did it to exit the hull.

[blueoval]

that's stupid fast great job man

[sketchman]

^ Why? I mean why run a pipe that long if you don't have to? If you just want a dedicated pipe, a short dump should be sufficient.

Just curious. Not hating.

[Dragonhealer]

I think it'd be super cool to run a whole car length wastegate pipe. Have it come out the back by the turbo exhaust pipe

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That's the way we did marine turbo diesels in the military......

[bhearts]

I think it'd be super cool to run a whole car length wastegate pipe. Have it come out the back by the turbo exhaust pipe

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[Advancedynamix]

Yeah, the trick with a large turbo is to use it together with a large external wastegate and a way to control the boost with a tunable map (controlled with a tunable engine management system).
Typically, you'd build an engine like this with a higher compression ratio, and tune the system to come on slowly at high rpm. The cam profile and port shape would be tuned for low to midrange power, and the turbo would work to broaden the usable TQ range. An engine like this can be tuned to have a very broad, usable power curve, but this takes a lot more planning and a very well designed exhaust manifold to work smoothly. The Festiva is a perfect car to build this type of setup, because it requires very little TQ to be fast. The BP in it's stock form is not a good engine choice though. Usually you would want an engine which could be reliably pushed to at least 8500rpm. If you push a BP hard at those revs for long you'll shatter things. The engines rod ratio is not correct for this type of job. If you destroked a BP about 12mm and increased the rod length 12mm, you'd have a stable and bulletproof engine that could be used to 8500rpm.
With a peak TQ around 5600 rpm and a turbo that doesn't become efficient until 4500rpm, you can see why this setup produces a short power spike. Your better off with a turbo that is most efficient at 3500rpm (crankshaft rpm, obviously not turbine rpm) which would give a smooth and broad tq curve.
You can spend all afternoon comparing turbine and compressor flow maps with the theoretical needs of your engine, but I find it much more effective to just study the results of similar setups with different chargers. Even the turbo manufacturer will admit that the maps are theoretical, and subject to many variables. The dyno, and racetrack are the only true way to be sure what works. We are lucky to live in a time where dyno graphs are commonly published by enthusiasts. Just be leary of any DynoJet graphs as a DynoJet is not an accurate way to measure power. Also, don't look at a dynograph for ultimate numbers, instead pay attention to the way the engine delivers TQ. This can be difficult to compare because graph scaling will be different from one test to the next.

[bhazard]

That's what I'm afraid of. Though my automatic trans might smooth it out a bit. Could a boost controller help smooth out the power?

[Advancedynamix]

The HX35 works on a 1.8 engine, but it's not a good match. To understand why you'll need to think about how turbochargers make boost, and how that boost works inside the engine.
Boost pressure with a centrifugal compressor is accomplished by inertia of rapidly accelerated air molecules. Using too large of a turbo will result in a violent boost curve. When the engine finally makes the exhaust energy necessary to spin the turbo fast enough, it is then confronted by a massive amount of air. When I was first getting into turbo engines I thought it was cool to have a boost curve that dumped massive amounts of air at the same time as the engines natural torque peak. This feels incredibly fast, and makes big numbers on a DynoJet dyno. What I came to learn though, is that it's not actually fast, it's destructive. The violent boost spike makes TQ that is hard to put to the ground. I got tired of replacing transmissions and being passed by cars with properly sized turbochargers. Now, when I drive a car with an excessively large turbo I get frustrated because the power is hard to use, and inconsistent. It's not hard to use because it makes too much power, it's hard to use because it makes unfavorable power. I like to go fast, not feel like I'm going fast when I'm just breaking things. Lol
The gt35r is a better choice than an HX35. I hope this China charger works like a real gt35.

[bhearts]

Does anyone have experience with professional rebuilds of oem turbos?

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