GSteg

iTrader: (15)

RMM said the actual boost is 5.7psi. It doesn't necessarily mean he's running on a 5.7psi pulley He could be running on a 8psi pulley witha 2.3psi lost somewhere in the system. You can change the actual pressure just by changing the inlet pipe of the system.

JPI Racing

Actually if you change the inlet pipe it won't make a difference on the boost reading. On the RMM kit if you running the same belt configuration, Your boost level will get up to 7 psi and then belt slipage and breakage is the problem. This is reason why we had to change Speedadic(aka thomas) belt ruoting. The intercooler contribute to the pressure drop also.
JPI

GSteg

iTrader: (15)

To my knowledge, physics has always told us there is a relationship between pressure and pipe size so as long as volume is constant. I'm not sure how you can change the pipe without changing the pressure while keeping the volume the same. Either I'm missing something, or the engineer at Kenne Bell (supercharger) lied to me. A buddy of mine with a turbo'ed Integra changed out his exhaust system for a larger piping setup and his boost reading actually decreased a bit. So something tells me pressure does change somewhat. If you can enlighten me, please do (I really mean it). I would love to get the number RMMGS4 is getting out of 5.7psi since I'm going boosted in a year or two.

IAGS400

Boost pressure is based on how much air you are forcing into an engine and how fast it can get out the exhaust. Changing the inlet piping will barely change your boost. Change your exhaust from stock to a free flowing exhaust will change boost.

(Not my GS) I lost 2 lbs of boost just by replacing my stock mufflers with Magnaflows and I didn't change the exhaust pipe size. Replaced the factory air box and inlet pipe to a cone filter and much larger piping and boost didn't change at all.

speedaddic

iTrader: (10)

Yep, if those are true whp #'s it would make me lean more towards a piggyback or standalone unit for sure. We'll have to wait til he gets it on a dynojet

RMMGS4

iTrader: (5)

Just flew in to LA this morning and luckily the hotel has free Internet.

Yes, this is what I'm questioning, how have others in the past based the boost numbers they are reporting?

I remember a year or two ago, someone posted they had a "stock" RMM set up with a 3.12 pulley ( I think) and were confused why they were only measuring something around 4lbs when RMM claimed 6psi.

Now that I have the kit, I realize that many of those who posted in the past, probably never measured their actual boost. They're probably just reporting the claimed psi based on pulley size, not actual.

So moving forward, I suggest people should report whether their "claimed" boost levels are actually measured or based off of pulley size and the estimated boost for that size.?

So for the record I have a 2.87" pulley, which I know others have claimed to be much more than the 6lbs that I am barely getting.


Hope this all makes sense now. Let me know what ya'al thinks.

RMMGS4

iTrader: (5)

As I mentioned earlier, I intentionally did the DJ run in order to back up the DP run. (See Post #39)

I vagely remember the numbers, but I WILL say the HP/ TQ values on the DynoJet were only a small % less than the DynaPack.

Sorry to tease you on the actual readings, but all I can say is that good news coming soon.

I wish Carlon would get that chart posted for me soon. Let me call him now.

Signing off now till tomorrow.

GSteg

iTrader: (15)

IAGS400, your boost will only change significantly if you have a restrictive inlet piping. Most of the the time, the exhaust will be the more restrictive system than the intake side anyways, which is why you dont experience large pressure loss in the first place. The loss may be small, but it IS there. I'm going to leave the subject the way it is. I dont want to go way off tangent to the thread's topic.

Give us a ballpark number

JPI Racing

Bigger doesn't mean better in this case. Now if you are pushing 35 psi through this supercharger then it's a different case.
JPI

JPI Racing

Glen hurry up and post that dyno sheet
JPI

jawnthen

DJ chart coming soon....how do I know, cuz I converted the pdfs to jpgs for glen...haha. I guess ya'll will have to wait until he posts but I can tell you it will be soon.

jawnthen

Okay I can probably say other than Glen, I've logged the most time behind the wheel of his GS. I didn't just take his car for a ride around the block but there were for longish trips.

First drive with the supercharger, pre-tuned. Driving from LasVegas meet 2007 to LA. I was driving his wife's IS when that broke down and to make a long story really short, Glen stayed with the IS to have it towed to Todd's shop and I got to drive the GS 100 miles so I could catch my flight out of LA and back to the bay. Anyways onto the driving impressions...The drive in one word was effortless. I was cruising around 70-80 and would quickly get to 110 in some stretches as I passed folks. The car felt strong in 5th gear. Actually it never shifted down to 4th when I gas'd it a bit. That prolly shows how light I was on the pedal. The most I probably got on it was 1/2 throttle. I didn't really have to go WOT before the car was going at highly illegal speeds. I definitely felt my chest pushed into the seat but it was never violent. It was a steady linear force.

Second drive after tuning. Got to drive the car 20 miles from Glen's house to EOS 2007. Whoa...is this the same car? For the first time in my life driving a GS, I was actually scared of the car. The car had ridiculous pull. So when I first got on the freeway and went again only 1/2 throttle, the acceleration made me chuckle. This time the push in the seat was violent. There was definitely some head snapping back. It caught me off guard how hard it was pulling. I had to left of the gas and hit the brake since I was running out of freeway...thank god he has those massive AP brakes. On a sweeping on fwy interchange ramp, I was careful on the throttle since this car definitely felt like it had the power to oversteer at 80 mph. Thats with VSC on, massive 295 tires in the back and whole lotta suspension braces to keep the car in check. My one note about his suspension setup, Tein CS v2 at full stiff, with every tightening bar imaginable still felt too soft for the amount of power this car was putting to the ground now. I don't know if that makes sense, but I would have felt safer if the suspension had more damping. Okay so back on a fairly straight freeway, I would get on the throttle bout 75% down and did that needle go from 80 to 120 in a couple seconds...sure looked like it. I didn't do anything scientific but more of an observation. All I know is the freeway wasn't clear enough to see what this thing could do. It was pulling hard at 120+mph with no sense the the power was running out at the top. After doing a couple of those runs I backed her down to 80mph again and I'd pause for a minute gather my thoughts and like a kid who got tasted candy for the first time went back for some more...haha. One last note, as we exited and got to a stop light, I couldn't help but try to see what would happen if I went WOT from a standstill....VSC still on, and remember he had 295 tires in the back....I got about half way into the intersection when the wheels started to spin out in the back. I didn't stomp on the gas pedal but more of a gradual push until it was WOT, but as soon as the tires started to spin, I got off of it. I know how expensive those tires are out back and didn't have permission to do a burnout.

So that's my impressions of the car. Its one scary beast! I'm gonna do FI down the line but I'm gonna keep it mellow. I'm perfectly happy if I can get the same performance of Glen's pre-tuned FI GS.

jesod

Any dyno numbers or track numbers? Sounds awesome though.