Picked up a JRSC

JaredKaragen · Post by **JaredKaragen** » Tue Jul 15, 2008 7:57 pm

HiProfile wrote:BTW the small bypass will work, but IAT's will probably be higher. Once it becomes a restriction, it is forced into the SC intake, which compresses it. You end up making the SC work slightly, while the turbo works a bit less. It really helps if you think of things in absolute pressure and Pressure Ratios. A JRSC is just as efficient when making 6psi or 16psi, if its still at a P.R. of 1.4 (14.5psi inlet and 21.5psi inlet absolute, respectively).

good info aside from the fact that the blower needs a sealed space on the outlet side to create any amount of pressure... but rock on. i didn"t think of a dual port wg instead of the oem vac valve

HiProfile · Post by **HiProfile** » Wed Jul 16, 2008 2:15 am

SC's always get me mixed up, plus that was a lot of typing & rearanging thoughts. It would actually force the turbo to overboost to create the same manifold pressure, and it would also be moving through the SC. In most cases, worst of both worlds in terms of efficiency. Using an EBC to control the bypass would let it open smoothly. If it was with a MBC, you'd have compounded boost, then it would drop suddenly when the bypass kicks open. Given the possibilities of your setup, you really would want gear-based boost as well as electronic control of the bypass. Or a REALLY BIG turbo, use lag for traction...

JaredKaragen · Post by **JaredKaragen** » Sun Aug 24, 2008 9:48 pm

Well, things have gone good; just using the JRSC right now; except one detail: No matter how the tune is; I always get a horribly lean jump when the gas is pressed; tipin is 100%; ok, whatever to that... and the second which is the most bothersome: every time the gas pedal is lifted; every time no matter how slight, my AFR goes to 10.0 and richer... .log and .cal attached. Don;t mind the ignition values; they are actually working great for my car (maybe another distributor problem again??? who knows, but they run great! F.Y.I Even though the last motor exploded as a cause of this experiment, I have found my solution; a vacuum and boost operated valve. They use a valve like this on the Saturn RedLine series cars, and it should provide seamless transition between turbo and supercharger. New motor is being built now; I am honing the cylinders so we will resurrect the idea once more

For the track that is

Post by **Gaskleppie** » Mon Aug 25, 2008 2:20 am

I see that you have not much vacuum during fuelcut. Playing with this settings will solve it I think. And shorten the 400msec delay a bit. Will help also. Why is VE enabled? We recommend this leaving it off. Look at your data what this does to your fuel corrections.

JaredKaragen · Post by **JaredKaragen** » Mon Aug 25, 2008 4:43 am

This is an older map that has always worked well since I got the JRSC; came with VE correction on when I got the .cal emailed to me; so thus the diffetrence; during the last updates, I have retuned to compinsate (new battery offsets, etc). But yes; the low vacuum is probably because I have the PCV hooked up on the JRSC as per OEM routing; This made me have to adjust my idle, and a number of other things when I hooked it back up (disconnected for turbo+JRSC) Yeah; I'll try backing off the fcut delay probably down near 250ms. The map ran great before with VE correction; so I am not sure what really gives; as you can tell I backed off of the motorola 2.5BAR and put in the OEM sensor so I could use this map; but I don't know; I am feeling this long tuning stretch (last 2 months) was in vein, and I should start anew once more; I definately have a good hand on what the IAT and ECT compensations need to be; now that the weather has been cooling down here in mid california; but I didn't want to have to start from square one again... heh. Thanks for the input though, much appreciated!