hypa

Since I'm running relatively low boost - 9psi on my jrsc, with no real opportunity to increase ot further without a serious increase in intake temps, is there anything that can be done with the jrsc manifold or blower to allow more air into the engine without compressing it any further?

I was thinking of modifying the exit of the jrsc. Looking at the exit of the unit, you can see that there could be benefits to slightly opening the port, and adding a radius to the edges. Am I right in this line of thinking, or out to lunch?

The manifold could be cleaned up, but I can do that myself. Just some minor casting imperfections. Besides, I don't think that there are any real gains to be had on the intake side.

On the head, I was going to slightly open the exhaust ports. Going into the short primary Kami header, this should give me a slight increase when the boost kicks in. Other than that, I'll be adding a larger diameter TB, and some Hondata tuning.

Is there anyone (other than TOO) who can actually modify a positive displacement supercharger?

Are there any real benefits to doing this?

Please don't say "Go turbo" because I've committed to the jrsc for this season, and autoX'ing a turbo car isn't as much fun as competing with a blown one. Just ask my competition last season

falcongsr

i dont think so.

and i wont tell you to GO TURBO...i'd recommend a smaller turbo with standalone that has antilag to keep the turbo spooled, but thats expensive and high maintenance since it puts much more thermal stress on the whole exhaust system.

austrian type-R

So, you think so? I AutoX my turbo ITR 10times in a season, it is soo much fun as with the JRSC, when not even more.....and trust me....I know what I talk about...had an JRSC

BudaKai

I not going to say it, but Falcon's right.
If you start going at the exit of the supercharger your going to either lose some of your boost, or lose efficiency. The opening was made that big to keep the boost in a concentrated flow so it doesn't flow back as much as it would with out that specific opening. It was designed that way for a reason in other words. As far as the manifold mine was nasty so we took a dremel to it and the temps dropped slightly, but I don't know about the newer ones though.
Buy a turbo you won't regret it. If your having problems when you fall out of boost maybe a stroked NA car is for you.

hypa

I have a turbo vehicle, and even with the mods I made to it, it still lags.
With the jrsc, I have throttle response equal to that of a well built inline 6, and a sound that puts the "whoosh, pshhhh" to shame

tzsir, I have no problems with actually lowering the boost levels, if I could get more air into the motor. I'd much rather have cfm than boost. I'm also building the car with stock compression which should make it a killer on the autoX, lapping days, and with a bit of nitrous, a killer on the 1320.

To the guys who have had a jrsc before, why did you change?

I love driving my car.
It hits 60mph in about 5 seconds, and 100mph in about 12 seconds as it stands.
The jrsc is a great system, it just doesn't have the support the turbos do. That's what I'm trying to create here. I'm trying to show people that it is a great method of modding a car, and for most people on the street/autoX, it is a better way to go.

hypa

something to add here.

I'm GE sleeving the block to a 1.9L, running a Hondata stage 4b, full exhaust, Iceman intake system, and a Zex kit for the drag. So next season I'll still be able to go turbo if I decide that I've maxed out the jrsc, and with the stock high CR, still have great off-boost drivability.

volitaire

you sound like a ricer :D

but i guess you'll need all the help u can get to catch up to me!! ahahah

ur pretty much topping out the jrsc with your planned setup anyways
go turbo

Def

JRSC cars are not dyno queens, but they can be pretty quick. They reach their upper limits relatively quickly once you start trying to go for more power over the base kit though, and I think that's why most people lose interest in the kit and go turbo.

TOO isn't some magic porting fairy or something. You can do anything he does with a die grinder. Just don't go too extreme if you don't know what you are doing. Basically, make the path the air wants to take slightly larger and make it as straight as possible. Can't really lose there, as you will reduce pumping losses in all situations.

I hear the S-tube is an area where you can pick up quite a bit of efficiency. Get a decent grinder and concentrate on the short radius. Try not to appreciably increase cross-sectional area, but make sure you open up the path that the air will want to take(D-shaped ports are always a good starting point here IMO). It doesn't sound like you want to get too crazy on the blower, so just use a weekend to 'clean-up' parts of it. You probably won't notice much difference, but lower intake charge temps are always a good thing, especially when you drive your car hard for longer than 13 secs.

hypa

Def, thanks for the well thought out reply. Exactly the kind of thing I was looking for

I completely forgot about the "S" tube. If memory serves correct though, it was a rough area that could very well be cleaned up. I'll look further into this tonite when I get home to my big box o' parts.

I know I'm coming close to the limits of the blower. Without any consistant method of cooling the charge (other than water), I'll need to make up the power elsewhere.

Antoher option could be to run pullies equal to 14psi (the max I'd ever take an M62 blower), with a cooling shot of nitrous when at that level. Using a boost limiter I could turn down the boost when it comes time for street driving or autoX.

The best of both worlds?
I hope so.

If not, then next season I'll go turbo (or jrsc'd H22).


thanks for all of the replies so far.

and volitaire, wait until we do a lapping day in the rain. You'll spin into the mud at turn 5 and 6 of MRP, just like every other MR2 that 's followed me hot into those turns

volitaire

then only thing that'll be spinning is your head when i lap you about 50times

my suspension is tuned and i know how to drive so spinning will be hard to do

Gearheaded

First of all, let me commend you on your stubborn sense.

If all you are looking for is cooler temps, then there are various way to do it, if you know what you are doing...IM me, and I'll let you know what my friend did to his JRSC, running at 12psi all night and all day, w/ almost non-existant heat saturation... It costs a little, but I've driven his car, and it's well worth it...

No I;m not talking about water misting it, or whatever that is either...just IM me...

cool?

Late,

Jay

hypa

Thank you gearheaded.


check your PM.

ModAddict

Don't keep it a secret, do tell! ......or im me please?

slammed_93_hatch

have you ever thought of doing a intercooler system on it i know a long while back so dude on civicsi.com or something like that a guy on there did a custom IC kit. i know its not exactly what your looking for but hey can't go worng with lower temps

Rory Breaker

That sounds like some SERIOUS overkill I think you may want to research it a bit and see what goes into a setup like that, and how you can make it more efficient aside from the water injection.

Good post, BTW...Im on the same page as you man, I'd just like other people to take the falls and be the guinea pigs first

speedy108

Gearheaded: What's the secret?

lazerus

probably something called a 'supercharger intercooler'

hypa

I'm curious as to what makes this an innefficient system?
Running the system @10psi with the water injection will make the car a serious street runner, especially when it's been Hondata tuned. The 35 shot will cool the charge even further, while adding oxygen to the fire.

With the nitrous, traction, and a lucky day, a 2600lb GSR could potentially make 300whp for a power to weight ratio of 8.6:1 The ultimate addition would be a boost limiter, so you could run a pulley that shows 12psi when you're on the nitrous, and still run 6psi at the autoX, or street.


Thanks for the
I have no problems being a guinea pig, since I'll be Golden Eagle built to 45psi. Of course I'll never see that on an M62 blower, but the overkill build on the bottom end gives me a bit more confidence

An aftercooler would be nice, but I want to wait until someone is willing to prove their design by dyno tuning and racing it. I've seen dyno sheets of SOHC jrsc cars gaining at least 5whp across the WHOLE power range.

Of course I have to dyno my final setup to prove the gains.
And then race it, which is the whole point.



[Modified by hypa, 4:56 PM 1/19/2003]

hypa

Your setup is similar to the one I plan to run next season.
What CR will you be running when you rebuild the internals?

Smashback

Inline 6? You should compare it to something that makes real torque...like an SOHC 427 Ford

falcongsr

everything with JRSCs is shrouded in secrecy. All the high power JRSCs that will make more power than any turbo? they are hidden away.

500 hp JRSC dyno plots? kept under lock and key.

27psi blower pulleys? they are made of a special metal NASA invented called unobtainium. YOU cant get em.

video's of JRSCs deep into the 8s at the track? they are confiscated and destroyed.

what about the time slips you ask???? they are shown to the driver and then eaten by a track official.

JRSC intercoolers are made of a special hybrid material that consists of peanut butter and carbon fiber that allow them to cool the intake charge to -27F without the use of a heat exchanger.

being a JRSC owner is like being part of the most secret gov't organization. you cant even go fast or it might attract too much attention.

wicx

JRSC

FMXer

There will be men in Moss Motorsports jackets and dark sunglasses ariving at your house shortly for speaking of the federation of JR owners.

[evil smirk]sure kids you can never have a fast SC'ed four banger, always buy turbos[/evil smirk]

BudaKai

Good one Falcon .

norcalcrx

Please do tell or im me also.