<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Well, P-51 you're the 1st that I heard to say this.<HR></BLOCKQUOTE>
That is probably because I'm the first person who isn't trying to sell you a product.
People selling roots blowers will tell you an intercooler isn't necessary, that is bacause it's almost impossible to put one on.
People selling you a turbo will tell you it *is* necessary, because they want to sell you the extra part.
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>I am talking about this type of supercharger, with 6-8lb of boost. I haven't heard anybody else sugesting the necesity of an intercooler on these. <HR></BLOCKQUOTE>
At that level of boost, an intercooler is not *necessary*. But it will still benefit if you put one on.
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>I've heard of the sugested oil cooler - about 100 bucks, that I agree.
On the other hand every turbo application without an intercooler, gives huge variations on the dyno, as well as on the 1/4 mile. Every turbo kit manufacturer will insist the necesity of the intercooler.<HR></BLOCKQUOTE>
Yes, of course it will show huge variations on the dyno, but let me assure you, the supercharger will vary just as much.
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>And let's make it even easier.
Are you saying that a turbo kit is cheaper to buy and install, less stressfull on the internals, and doesn't need any "superchip type" modifications? Let's supose for the sake of the argument that both that turbo kit and the supercharger work with 7lb of boost.<HR></BLOCKQUOTE>
Ok, yes, let's talk *for a given boost*, say 7psi.
When I look at a turbo install without intercooler, and compare it to a roots install... I'd say they are about the same. A centrifical supercharger could be easier than those two.
Cheaper to buy? The JRSC is $3000? Then yes, a Turbo should be less for a non-intercooled version. I've seen turbo kits in Europe for as low as $2000, and in the US for around $2500. Just depends on how much money the vendor is making.
Less stressful on the internals? Again, for a given boost, my vote goes to the turbo. First of all, you don't have the extra drag on the crankshaft that a super has. Second, a turbo is more efficient than a roots blower. That means the air does not get as hot, *for a given boost level*. Less heat means less detonation=good. The turbo would lose in the underhood heat battle however. The roots blower would get less hot under the hood which is good for things like cooling, and the rubber and plastic bits.
Performance? A turbo should not need a chip any more than a blower does. They both need more fuel, they both need less timing. However since the roots heats the air up more, it will need even more timing retard, so in that regard, it may actually need a chip more. A roots is supposed to have the advantage of more boost lower down, better low rpm response compared to a turbo. But according to you guys, that isn't true. You all keep saying that the boost is high up, I don't know why. If anything, your blower should be making more power down low, and less power up high since it's spinning faster and is even less efficient. All the roots installations I've seen, wether factory or aftermarket, make full boost at ~1500rpm, compared to ~2500-3500 for turbos.
HP? Well, once again, a turbo will heat the air less for a given boost, therefore it is more dense. More dense=more power.
Now, there's something you have to understand. With a turbo, it's very easy to whack the boost up to 15-20 psi. Very easy. At these pressures, an intercooler becomes *much more* important. But still not *necessary*. The XR4Ti runs 15psi without an intercooler. But it only makes 170hp, compared to 210 out of the Mustang SVO with the same engine and turbo, but with an intercooler.
The reason people think that turbo need more fuel, and *need* an intercooler is because once you go and install your 7psi kit, with the twist of a screw you can run 15psi. Now you *need* more fuel (chip) and an intercooler. That is why they have that reputation.
There's a lot of crappy information out there. Some of it comes from people who are trying to sell you whatever it is they have and bash what they don't offer. Othertimes it is people who don't know what they're talking about, and just go on hearsay. "Yeah, my friend blew up his turbo motor because he didn't have a chip". What they forget to tell you is he cranked the PSI up to 20. All you hear about is turbo=dead engine.
