Spoiled

Im considering doing a turbo setup on my S2000. One that would only boost 6 pounds at the most..

Heres the thing. Ive turboed two cars in my lifetime and I did in the past, turbo a Civic Ex which ran without an intercooler but with a rather small turbo. The kit was by Greddy.


Also I turboed a type R...but that doesnt matter.

Heres my question. Do you think it would be sensible to run a turbo setup only boosting 6 pounds without an intercooler?
I know its a different ballgame to reference, however, the comptech unit does not run with one, as well as the Jackson Unit (but its not on the S2000).


what do you think? Im assuming an intercooler might be more required if I was to use a bigger turbo no? But Im not exactly sure.



any help would be appreciated. Thanks

JBoggs

https://www.s2ki.com/forums/showthread.php?...ight=SPEEDCRAFT
see this thread most info about turbo setup can be found inside there

mechy

I consider it would be safe but then again, 6 pounds? This wouldnt improve much performance, and even worse without the intercooler.

You would get about 5-10% more power, and this beeing such a little turbo, the improvement will be noticed through the low rpms (2000-6000), since at high rpms (7000-9000) the naturally aspirated air will be sucked in faster than what the turbo can pump!

P.S. To anyone putting a turbo on their s2k, you could tweak a little the timing chains since the vtec decreases the efficiency of a turbo!

jerrypeterson

5-10% is a pretty low figure for close to a half bar of boost. Whether full boost occurs at low RPMs is dependent upon several factors including turbo size and configuration. With the added overlap in the cams VTEC profile you will lose some efficiency, but that isn't much of a concern. Take a look at the dyno charts for the Comptech supercharger or the Speedcraft Turbo kits(intercooled). It isn't black magic, its forced induction. Inefficiencies aside, people are receiving much more than a 5-10% enhancement in horsepower off six pounds of boost.

What "timing chains" are associated with the cams on a F20C?

mechy

I should have stated 10-15

Yes but have in mind turbos are NOT 100% efficient, they add back pressure to spin the turbines which decreases efficiency, and 6 psi is almost half bar boost having in mind that the ambient pressure is 14 psi (which varies depending on place).

The key here is that it does NOT have an intercooler, if it had, the % would be much higher, so there it looses some more efficiency (6 psi intercooled would do around 20-30%).

Im not an expert on S2k engines since I unfortunately (EXTREMELY) dont own one. But I do own a 95 Civic Si VTEC and its VTEC like the cams are handled by timing chains, so I figured maybe the K20C (which i can infer is the s2k engine) was like this too.

I might be wrong though, these percentages are estimates, I havent verified them.

jerrypeterson

The Speedcraft turbo in the link above is supplied with an intercooler.

tantheman

Sorry, don't know much just like to post. Although turbos due make your cars less reliable.

Tan

netwiz

???? 10-15%? I don't think so. The output of a FI engine is directly related to the amount of boost you can put thru it. If you double the pressure (14psi or so), a 2L motor will behave as if it has 4L of displacement. Triple the boost (like on some high-boost Supras) and the 3L straight-six makes power like it's a 9L NA engine. This isn't completely accurate, as you lose some efficiency due to the heating of the air during compression. But suffice it to say, 6psi of boost will produce about a 30-40% increase in power, assuming the turbo's tuned to the size and RPM of the engine.

And there's nothing innately less reliable about having a turbocharged vehicle. True any increase in complexity bumps the chances of something breaking, but w/ proper operating procedures (turbo timer, religious oil changes, etc.) there's no reason a turbo'd car will give you any greater difficulty than an averagely maintained car.

mechy

First, F1 as in Formula 1??? F1 does NOT use turbo, its CART, and the turbos are NOT even close to the size of a 6 psi, they use a turbo around 19-22 psi. (they do 900+hp because of their super high revability, not because of the turbo, which increases TORQUE)

10-15%? I do think so, a 6 psi doesnt pump 6 psi steady, there are various factors that can change this. This small turbo will have difficulty supplying the engine air at higher rpms. Perhaps 20% at its most would be possible.

A 9psi without intercooler (a friend of mine has one) gives you perhaps a 35% increase AT THE MOST, and you should have to decompress (to avoid knocking) the engine first to add this turbo, which will make the percentage decrease more.

10-15%? Yes again, you will benefit from it perhaps from idle-5000 rpm, higher than that, most of the exhaust will go through the wastegate.

RT

Make sure apples don't get mix with oranges here, the Comptech SC (non positive displacement) only gives the full 6.5 psi boost at 9,000 RPM (at 6,000 RPM it's only pumping like 2 psi or so).

And to answer the question "Have a question who TRUELY knows about turbos" I know enough about them to realize I don't "TRUELY" know about them. What?