Joseph Davis

Uhm.

I don't think many people understand precisely what a Roots does, or how to harness it.

hypa

All I can say is that this is probably the best thread I've ever taken part in regarding the turbo vs. JRSC argument. Both have their place in the scene, both offer their own special brand of power delivery, and both will put a big assed smile on your face.



And smaller turbos run out of CFM just as quick as the jrsc does. Imho comparing a T28 @8psi is equal to an M62 jrsc at 9psi.

Naterror

Thats the same kind of power increase my buddy made going from his JRSC @ 11psi to a Drag kit w/SC61 @ 7psi. Same exhaust, tuner, and dyno. Thats in 99-00 Si.

Cliffjumper2

bookmarking thread for further reading later tonight

klungemonger

The Kamikaze header seems to be commonly used for JRSC but I don't know why, it's not a good header! The 4-1 design with short primaries and a long fat tube is very unfavorable to low-end power. With stock boost setting on the JRSC, or even a couple psi more, any other header would probably produce better results. Even forced induction can benefit from a well tuned exhuast rather than just putting on the hugest piping you can find.

To illustrate: some might remember a few years ago SCC mag built a 5g hatch with stock Z6 engine on a JRSC with hopes of hitting 150mph. They squeezed 12 psi out of it and tried a different intakes & headers. Ultimately the goal was peak top-end power so they used a Kamikaze header but they said for any street car they would not recommend it since throttle response, low-end, & general drivability was poor compared to the Stillen 4-1 long primary tube design (just like the DC 4-1).

So at 7psi you'd have been way better off for dyno and street using probably either DC units, a 4-1 or 4-2-1...

Aerodeck

Hi,

Two pence from Europe.
This dyno is not fair to a JRSC. Leave out the intercooler on the turbo setup and test again.
Or give a very small shot of NOS on the blower and see which figures it makes then.

beepy

I would like to see a turbo vs. a centrifugal supercharger. That eliminates all of the variables.

hypa

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Aerodeck &raquo;</TD></TR><TR><TD CLASS="quote">Hi,

Two pence from Europe.
This dyno is not fair to a JRSC. Leave out the intercooler on the turbo setup and test again.
Or give a very small shot of NOS on the blower and see which figures it makes then.
</TD></TR></TABLE>

I tend to agree with you on this, however, I know that typical turbo installations will include the IC, therefore it's a realistic dyno comparison. I would really like to see a jrsc dyno from one of the people who bought the intercooler kit. An IC'd jrsc @ 10psi, vs Drag @ 10psi would make for an interesting comparison.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beepy &raquo;</TD></TR><TR><TD CLASS="quote">I would like to see a turbo vs. a centrifugal supercharger. That eliminates all of the variables </TD></TR></TABLE>
It really would have nothing to do with our dyno comparison regarding jrsc and turbo, it would be neat to see a Vortech @ 10psi along with the above.

dumpeDc2

um... one is street leagel and the other is not. you should have done like the greddy kit vs. the jackson raceing. this doesn't really prove much next time do the vortec super charger vs the drag3. but ya I still think aturbo is better or :I would have got a supercharger instead

Rory Breaker

Some of you guys blow my mind. Im not even going to address the "you should haves" and "why didnt you just test every product on the planet" lines anymore. Go do your own dyno testing with your own money then. Maybe if I reiterate myself and my intentions, you'll figure it out.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">This comparison was basically your off the shelf JRSC kit with Hondata, Kami header, etc etc, the usual stuff @ 6-7PSI vs a Drag kit with Hondata @ 7PSI. Same motor, same car, same tuner, etc. Both setups are what many people would run when deciding turbo vs sc, this just gives them a heads up in terms of how much and where they'll get their power. Not really saying one way or the other, just illustrating the powerbands and providing people with more information.</TD></TR></TABLE>

For the record, I also would love to see an intercooled JRSC vs a Drag. But then the price comparison isnt so fair. IC'd JRSC vs Full Race kit, maybe.

And I dont agree about the Kami header. It worked beautiful for me, every car Ive ever seen make impressive JRSC power has used the Kami (or, in its defense, the JDM DC 4-1). To say any other header would be better is a ridiculous, bold statement. Are you JRSC'd? Do you have a Kami header? Have you seen one, and compared it to a DC? Have you taken a, say, Comptech header off of your JRSC'd car, then put on a Kami and felt the difference? If not, how can you make such a statement?

Dont even bring up SCC. I did the test, I drove the car through its stages myself, this is not about what a magazine article told me. Which is more trustworthy, real world experience, or magazine racing? I couldnt imagine anyone would want more low end with a JRSC, it goes when and where you want it to. Top end sucks, it feels like it peaks at 6k. I'd sacrifice a TON of low end for top end power with a JRSC, and anyone who says otherwise, I cant imagine has ever driven one.

Throttle response was poor with the JRSC? Give me a break. With my Comptech and clogged stock cat, throttle response was still instant. Comparing a magazine article from 5 years ago on a completely different motor to someones real world unbiased results just makes one look uninformed. (Not to come off like an ***, its actually a beneficial discussion youre bringing up...better than "you should have done a Vortech )

program

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by newgsrdriver &raquo;</TD></TR><TR><TD CLASS="quote">

I still dont see any downside to a turbo setup vs the JRSC for daily driving.

</TD></TR></TABLE>

What about boiling your oil? what about extremely hot intake temps because intercooler does nothing in stop and go traffic? I love turbo setups but if your stuck in L.A. traffic at 100 degs, I'd rather just be heating the air insted of both. And you could also add the LHT unit and save both. But just talking for daily driving.

Ben Huynh

iTrader: (6)

How exactly do you boil your engine oil? If you're boiling oil, you've got bigger things to worry about than what the temperature is outside.

The old turbo vs. supercharger debate is back. I don't think it was Nick's intention to start this up again. He was just sharing his experience and I'm impressed he went to all that trouble. Thanks for the info Nick.

Joseph Davis

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hypa &raquo;</TD></TR><TR><TD CLASS="quote">And smaller turbos run out of CFM just as quick as the jrsc does. Imho comparing a T28 @8psi is equal to an M62 jrsc at 9psi.</TD></TR></TABLE>

They do?

OK, lets ASSume they do. What are our ASSumptions on charge exit temps - that's what matters when comparing VE in this case.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beepy &raquo;</TD></TR><TR><TD CLASS="quote">I would like to see a turbo vs. a centrifugal supercharger. That eliminates all of the variables.</TD></TR></TABLE>

.... does it now?

program

HAHAHAHA... Ok, first off, I obviosly don't meen litterally "boiling" the oil, what i ment was, heats the oil up to an excesive point. Sorry about the slang. I deffinitly like the post its a great comparison. Its just when you bring up "daily driving" its a whole defferent ball game.
Oh, by "ball game" i meen that it would fall in a differen catagory.

ludetech

I honestly think that if anyone was to really take a look at all of the options and turbo sizes compared to the sc. I dont understand how anyone could go sc except if they prefer the sound because you can get better downlow power on a greddy kit than the jrsc. I mean I think about it and its just very hard to say. I just see so many more possibilities with a turbo and a setup specific to your needs

ludetech

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by program &raquo;</TD></TR><TR><TD CLASS="quote">HAHAHAHA... Ok, first off, I obviosly don't meen litterally "boiling" the oil, what i ment was, heats the oil up to an excesive point. Sorry about the slang. I deffinitly like the post its a great comparison. Its just when you bring up "daily driving" its a whole defferent ball game.
Oh, by "ball game" i meen that it would fall in a differen catagory.</TD></TR></TABLE>

I see plenty of people daily drive a turbo car over sc and I will tell you one thing if your so godam worried about oil temps get a oil cooler. and I beleive a turbo car is more reliable #1 your getting better gas milage down low and your putting less stress on your motor in a daily drivin situation. also the charged air is cooler in a turbo setup.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by program &raquo;</TD></TR><TR><TD CLASS="quote">

What about boiling your oil? what about extremely hot intake temps because intercooler does nothing in stop and go traffic? I love turbo setups but if your stuck in L.A. traffic at 100 degs, I'd rather just be heating the air insted of both. And you could also add the LHT unit and save both. But just talking for daily driving.</TD></TR></TABLE>

because your not boosting in stop and go traffic numb nuts unless your stupid and you run up to 5k rpms everytime you shift when daily driving


Modified by ludetech at 2:33 PM 7/23/2004

program

Wow a little sensitve about the whole sc/turbo debate. I didn't mean to get you all upset . Look I'd rather have a turbo also. I'm just pointing out the the opposits to end all the SC bad mouthing. Ya might want to read a book on this or something too (not trying to sound mean). You don't have to be boosting to creat heat from a turbo or sc setup "numn nuts". Your intercooler does 95% of nothing when your stoped. The drag 3 kit does not come with a oil cooler. You can build a turbo setup or sc setup for anydaily driven situation but we are just comparing these two particular kits the way they are. right? Try and step out of the turbo good supercharg bad way of looking at at stuff. They both have pros and cons out of the box, and they both can be modified to out perform the other. Also read some books.

ludetech

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by program &raquo;</TD></TR><TR><TD CLASS="quote">Wow a little sensitve about the whole sc/turbo debate. I didn't mean to get you all upset . Look I'd rather have a turbo also. I'm just pointing out the the opposits to end all the SC bad mouthing. Ya might want to read a book on this or something too (not trying to sound mean). You don't have to be boosting to creat heat from a turbo or sc setup "numn nuts". Your intercooler does 95% of nothing when your stoped. The drag 3 kit does not come with a oil cooler. You can build a turbo setup or sc setup for anydaily driven situation but we are just comparing these two particular kits the way they are. right? Try and step out of the turbo good supercharg bad way of looking at at stuff. They both have pros and cons out of the box, and they both can be modified to out perform the other. Also read some books. </TD></TR></TABLE>


you need to read some books, your air is warmer when you are stopped but what makes your air heat up in the first place is boosting. the friction from the turbo creates heat and air runs through the turbo creating boost. your air will be warmer but not by much and the turbo wont create anymore heat than an sc.

program

A turbo at a stop will produce just as much if not more heat. The air has to travle through more heated pipes and not to mention a super heated turbo before it gets to the motor. While boosting does creat a sumbstantail amount of heat, you air (& oil on a turbo) will still be heated a great deal while stopped. Do some research, Im serious I'm not trying to be a dick, it just sounds like you don't believe me.

beepy

If you are using a water-cooled turbo, the heat absorbed by the air passing through the turbo would be about the same as by the air passing through the coolant-heated throttle body in a stock engine.

I would think that many people prefer SCs simply because they are completely bolt-on, and because there is less that can go wrong.

How many things can go wrong with a turbo? Lots of things, everything from oil coking to bad seals leaving oil in the exhaust to failure to make boost for a half dozen other reasons.

A SC has only a few things that can really go wrong, (depending on if we are talking roots or centrifugal), since they do not involve the exhaust, wastegates, blowoff valves, lots of piping, and many are self-lubricated.

program

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beepy &raquo;</TD></TR><TR><TD CLASS="quote">If you are using a water-cooled turbo, the heat absorbed by the air passing through the turbo would be about the same as by the air passing through the coolant-heated throttle body in a stock engine.

I would think that many people prefer SCs simply because they are completely bolt-on, and because there is less that can go wrong.

How many things can go wrong with a turbo? Lots of things, everything from oil coking to bad seals leaving oil in the exhaust to failure to make boost for a half dozen other reasons.

A SC has only a few things that can really go wrong, (depending on if we are talking roots or centrifugal), since they do not involve the exhaust, wastegates, blowoff valves, lots of piping, and many are self-lubricated.

</TD></TR></TABLE>

warhorse 4.6

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">Uhm.

I don't think many people understand precisely what a Roots does, or how to harness it.</TD></TR></TABLE> You just may have a point my friend. But let me tell you I had a chance to drive a GSR with a JRSC and it pulled hard down in the low to mid range. It was not that strong up top like a Turbo or Centrifugal would have been. It would be nice if we could see a Roots blower with a cooler on it. On mustangs Roots Blowers make 315Rwhp and 360Rwtq on 8psi intercooled VS Turbos Stangs 390rwhp and 420rwtq 8psi intercooled so the turbo will still out performe the Roots blower pound for pound.

Joseph Davis

Pound for pound, pfft.

Roots kills intake harmonics and most of the exhaust harmonics, acts as a check valve to prevent reversion. Flow through the head is completely alien to other setups, even other blowers.

If you look to the i-VTEC cars with JRSC, they are dialing cam angle all the way forward (more overlap) as soon as VTEC is engaged (higher lift and overlap cam profile), and keep it there, they've been known to make 260 whp at 5 psi... sounds like turbo numbers to me. No other i-VTEC setup likes that much (sustained) cam advance, and nobody but a Honduh owner would run so much valve overlap with a forced induction ride - all the mainstream dumbestic guys (not to be confused with the hardcore domestic guys) focus on cam LSA and trying to eliminate overlap.

I propose that people lack the fundamental understanding to properly build an engine to suit a roots blower.

Naterror

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">Pound for pound, pfft.

Roots kills intake harmonics and most of the exhaust harmonics, acts as a check valve to prevent reversion. Flow through the head is completely alien to other setups, even other blowers.

If you look to the i-VTEC cars with JRSC, they are dialing cam angle all the way forward (more overlap) as soon as VTEC is engaged (higher lift and overlap cam profile), and keep it there, they've been known to make 260 whp at 5 psi... sounds like turbo numbers to me. No other i-VTEC setup likes that much (sustained) cam advance, and nobody but a Honduh owner would run so much valve overlap with a forced induction ride - all the mainstream dumbestic guys (not to be confused with the hardcore domestic guys) focus on cam LSA and trying to eliminate overlap.

I propose that people lack the fundamental understanding to properly build an engine to suit a roots blower.</TD></TR></TABLE>

I was thinking the same thing. What a lot of people don't understand is how dangerious the roots type blower is. JRSC is not a root type by diffinition, it's a centrifical type. The difference is in a roots type the blower housing and intake are pressurized and in a centrifical only the intake gets pressurized under the blower, because of rotor design and its much safer than roots type.

But back to the topic, great comparison of complete kit comparison. To address the street legal topic, not everyone has the strict emission testing that places like CA and Houston have.

Joseph Davis

LOL. The Eaton blower on the JRSC is a centrifugal. Right.

You were thinking anything I was in re Roots charge harmonics, reversion, the desirability of overlap in forced induction setups, Dark Side tuning. Right. Sure you were.