The U20SED track-reliable power limit.

N/A tech, Cold Air Intakes, Spark Plugs/wires, Cat backs, Exhaust...etc

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gse_turbo
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Re: The U20SED track-reliable power limit.

Post by gse_turbo »

Most of the gains in RPM will come from top end upgrades. Balancing everything in the bottom end just insures that the bottom end is working with the top end and not working against it.

As far as my site, it's pretty much been reduced to simple information. All the store pages have been taking down because the host I've been using doesn't support a proper database for products. Right now all product requests are taken via email or through the forum.
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Efratech
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Re: The U20SED track-reliable power limit.

Post by Efratech »

garrido,

Mine is not a U20, its an 20XE. it had 150 at the fly in factory form.

We made a custom intake manifold and a Honda ECU hybrid (can be fully mapped) and after a few dyno runs it made 148hp 130+tq at the wheels and the limiter is set to 7250.

Is a norm to use aftermaket rod bolts on these engines to rev it to 7500+.

I understand that with a good exhaust manifold, a good intake manifold, a bigger throttle body, rod bolts and some porting and a megasquirt you can achive the 7500 limiter and 170+ at the fly you're looking for and still be very reliable.

I trashed mine everyday of the week for over 3 years and no mayor issues.

Right now is sitting in my parking space waiting for a rebuild.
'88 Pontiac Lemans GTE - 2.0 16v XE - fully programable ECU, Custom made intake manifold and other bits.
146.6WHP/135lb.ft - 14.81@94mph
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PrecisionBoost
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Re: The U20SED track-reliable power limit.

Post by PrecisionBoost »

garridob wrote: This sounds like a high rev way to build an engine. I'm not opposed to that per-se, but is an 8500 rpm us20d a rebuild it every 5,000 miles sort of engine?

I've heard the intakes are really bad, but my students fabricated a new manifold that should support higher revs. Am I barking up the wrong tree here?
It's the head design that is bad on the U20SED in my opinion, it requires extensive modification to help it breath, the C20XE/C20LET Cosworth heads are really free flowing from stock.

The U20SED head on my main project engine has heavy porting on the edges of the bends to straighten the pathway for air as well as stiffer springs and different valves with shaved stems, 5 angle grind, modified silicone bronze valve guides and a few other bits and pieces.

It was set to be happy running all day long at 8000RPM, but I would bet that I could take it a little further if I removed a bit of material from the crankshaft.


At times I still question whether it's still comparable to the C20XE head, at times I'm tempted to abandon the U20SED head and have a modified Coscast C20LET head shipped over from the UK.

In the end, modifying the U20SED head really doesn't cost much, most tuners that have a good idea about how to remove ( or add ) material on the head will be able to do a good job on the U20SED.

Even the combustion chamber could use a little work to clean up the shape for a more efficient burn at higher RPM


There are lots of options, again, nothing specifically cheap due to the lack of support in certain areas of the world.

The main places to look are UK, South America, Germany for tuning the U20SED ( simply look for X20XEV )
2010 BMW 335D
1994 Opel Calibra 4X4 turbo ( C20LET 2.0L Turbo )
2002 Daewoo lanos
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