Red Devil

A smaller pulley should equal a higher boost throughout the rpm range, not sustained boost for a lesser boost level.

We've spun a 1.0 L eaton blower to 6 psi consistently on a Renesis and boost does not fall. Were we to add an intercooler it would easily do ~7-8 psi without fail before hitting its 20 K redline.

I don't think that the size of the blower is your issue. My guess is between the 5 rib arrangemnt and jack drive that you have slippage. It would be in excess of 45 hp given the maps from Autorotor I have.



Also, I don't necessarily buy into the enthusiasm on this thread about using larger blowers. if you look at the data from Eaton or Lysholm the power to drive the positive displacement SCs is in direct proportion with the air and pr level. But the advanatage of the smaller blowers is a greater Ve and that should not be overlooked, imo. Even the engineers from Lysholm will caution oversizing blowers due to these issues.

morkusyambo

^+1. I would also like to add that I have seen and ridden in cars with sc tech from the 90's that would routinely spin .5 and 1 liter blowers well over the manufacturers recommended rpm limit for thousands of miles without issue.

The reason I want to see a larger blower is I don't like having to push 8+ lbs to make the power number that I want. Even if the larger blower has less VE, I would still be happy if it gave me more power/flow than I have now while only pushing 5 - 7 lbs.

Based on everything I have been exposed to, 5 - 7 lbs is the magic number for reliability and longevity.

Moon Assad

I like those Eatons. Cam runs one on his jet boat and it flys. Sounds cool also. Putting the 1.7 next to the 2.6 is surprising, there about the same size actually the 2.6 isnt as tall as the 1.7, isnt as wide either. Its just a little longer. The outlet port is huge, like 3 or 4 times. Rotational mass is about the same yet the KB seems a little easier to turn by hand.

Moon Assad

Definitely sounds like something is spinning. Check the pully on the blower. If you havent hit it with an impact thats going to most likely be the issue.

olddragger

iTrader: (3)

Its not just a bigger blower--other "stuff" is also being done.

marsredr100

iTrader: (1)

Watching the new SC developing, sounds great.

Meanwhile, raced at Sebring Sunday.

Track was still a little greasy from the 12 hours of Sebring a few weeks ago. Still learning heel/toe and driving with a more experienced group HPDE3.

Did not push as hard as I wanted too (shifting at 6500) cuz still waiting to have it dyno tuned hopefully on Friday May 18th before my next day race at Homestead.

Check out the videos

Rote8

Logs?

Rote8

A real cold air system would also be nice.

california style

Hi Juan, very jealous. I would love a go at Sebring (and Road Atlanta) as they are two of my favourite Forza tracks!

Hopefully for for my first proper sprint race of the year later on this month. Entrance just confirmed!

Galen Darkmoon

You go Juan, soooo jealous of those big tracks.

Moon Assad

How much higher is the mazdaspeed strut tower brace then factory?

olddragger

iTrader: (3)

about an inch? Maybe 2?

Juan are you coming to roebling Road with us next month? We are going to have a LOT of rx8's on track at the same time including 2 pettit cars
Road Atlanta is in June.
Californa-- I actually dont like Road Atlanta. I dont like that long back straight that is only a drag race. The braking going into 10A is a nice way to end it. But that back straight requires that I use 3nd, 4th, 5th and 6th gears at FULL LOAD. Its a dangerous track to drive ( even not on the edge)and has very little run off room in critical areas. I much rather drive Barber, CMP and Roebling with Roebling being my favorite. RR is a deceivingly challanging track to get right. Its also MUCH safer.
There has never been a helicopter transport to a hospital at RR, at Road Atlanta unfortunitly there are several a year. RA needs more run off room but they are too cheap to provide it.

slvrstreak

iTrader: (3)

very true Denny...they had to air lift someone out last summer at RA because they hit the wall and crossed back on the track (60's Elanor Mustang vs Prototype)
we all know why you don't like that back straight
I probably won't be driving RA this summer...it was just too dern hot last year in June...Don almost died of heat stroke

Rote8

Feelings can change. LOL

marsredr100

iTrader: (1)

I wish I could Denny but I don't have BIG pockets like you

Got to stick with NASA FL this year in order to make it up to at least HPDE4 and TT next year. However, there is always the lottery winning dream

olddragger

iTrader: (3)

Lol--now THAT is funny!!
Juan its only $225 for BOTH days!
Cheaper than renting the entire track like you do ( i never see any other cars )

Just saw the vids--you sure are getting comfortable on that track, very smooth, very little steering wheel movement etc. Yea it was obvious you where taking it very easy--but that is ok. I would too.
One question---the approach to the turn that happens right before the overpass--why dont you enter that turn from a wider approach? Make a later apex? Is the pavement bad out wider?

At road atlanta--thats a track in which you wish you had more safety equipment.

marsredr100

iTrader: (1)

Because

1- I lost it once at that turn going wide as you suggested and ended doing a 180 clockwise release brake cuz heading straight to inside wall to 180 counterclockwise and stopping about 6 feet from the outside wall. Thank goodness, no one behind me.
2. The track is REALLY bumpy on the turn (watch the video).
3. It is not a perfect half circle/turn (see attached track map).

olddragger

iTrader: (3)

ok --got ya--knew there had to be a reason
i am very cautious in a couple turns and one hill myself.
turn 12 ( downhill before the front straight)--i hold back there big time and cresting the hill approaching that same turn( its a gear change point and I have lost traction before because the car gets so light).
Makes sense.

marsredr100

iTrader: (1)

Picture or it didn't happen...rite?

Rotr8

iTrader: (2)

Awesome pic Juan

olddragger

iTrader: (3)

getting hooked aren't ya?

california style

1st official sprint test tomorrow! Wish me luck!

marsredr100

iTrader: (1)

Good L...err...Buena Suerte!

olddragger

iTrader: (3)

yee hiii!!

california style

arf, it was rubbish!

It was something called an auto solo. Cone tracks laid out, only 3 runs, then they changed the course! You never knew where you were going, and couldnt really drive fast..... it was more a "slow and steady" wins the race effort, and was held in FREEZING conditions which didn't help.

I managed to stick it for 1st 2 gos, but when they were changing the layout for the 3rd time, I just gave up and went home!
Ah well you have to try these things.....