jcbrx8

Nice, B! Man you keep pushing the envelope of the capability of our platform: 275 - 314 ft lbs on tap 4k to redline.

Brettus

iTrader: (2)

Cheers Curtis . Looking back and comparing with old logs I can see power/torque in the 4500 to 7500 range is identical so this manifold is indeed 400whp capable. Where I see improvement is from the 2500-4500 range and the 7500-8000 range . The low rpm improvement from spoolup and the high rpm (after I cut boost) due to the inability of WG to cut as much boost.
All in all ....it's definitely a quicker car now.

northzone

Brettus

What is your opinion of the exhaust porting work in this video? Would it significantly help the flow in a turbo set up? Additionally around the 6 min mark he discusses a cause for a the early (low mileage) failures. Could this be an accurate failure reason?


This shop is in my area and are known for quality work.

Brettus

iTrader: (2)

I think it would do very little as it doesn't really make the port flow better ...just open earlier which would result in a loss at low rpm and maybe a very small gain at high rpm. Although I have found benefit in doing a mod like that to the outer ports only. Helps with spoolup.It does nothing to address the port timing issue I talk about in the 450 thread.

Re the failure method ..yeah totally . I always smooth out that area he mentions for that very reason.

northzone

Thanks for the feedback. Thinking about it more later, I started to wonder if the area between the exhaust flow and coolant jacket would start to develop cracks and leak after the pressure and temperature cycles of a FI system. Figured that was dependent on how much material was actually removed but something that was possible if it was too thin.

Brettus

iTrader: (2)

Quite possible ..... there isn't much material at all to work with there. I generally port it at 45 degrees by about 4mm which just takes the corner off..... if you know what I mean. That keeps it at approx. 4mm from water to surface.

Brettus

iTrader: (2)

Came across something interesting the other day . Mazda uses this block off piece to block off and disable the VDI on 6 port auto S2 models.
Will use this in my LIM next time I'm in there.

Williard

iTrader: (18)

Thats actually quite interesting...

I've never seen that before.

Travis

Brettus

iTrader: (2)

Even more interesting is the little trick a guy local to me is doing atm. Taking S2 5 speed and S2 auto and converting them from 7500 slugs to 9000 rpm screamers. In the case of the 5 speed all that was required was a software change! The auto had a manual fitted plus the software change.

Williard

iTrader: (18)

I do know the 5 SPD manual is boasted as a more robust transmission and the optimal trans for an REW swap for most anyway.

I love the reverse placement of the R3 Trans personally.. It was almost enough to make me swap one in...

Dont discount backyard mechanics , they can surprise you

Travis

AAaF

I dont get why? Then again, I did not know that they made 6 port with auto, guess I've been sleeping in the S2 development....

Did they stop producing 4 port, but then partially strangled a 6 port to be able to use an auto trans in it?

Brettus

iTrader: (2)

Basically they did exactly that . They also made an S2 5 speed 6 port and strangled that as well for the sole reason of making sure the 6 speed was the premium high power product. So if you get a 5 speed manual S2 with a 7500 redline ....all you have to do is put a VDI back in the hole , adjust the software and VOILA ...9000 rpm redline with same power as the 6 speed.

wannawankel

Did they reduce power in the S2 AT to reduce torque delivered to the transmission to keep it from failing?

Brettus

iTrader: (2)

No ...nothing to do with torque and everything to do with rpm.

Brettus

iTrader: (2)

Putting it on the dyno tomorrow

3toedSloth

How many kms/miles are on your short block?
Looking forward to the dyno results.

Brettus

iTrader: (2)

Todays dyno . Pretty happy with this . Didn't want to push it any further with the 0.83 housing as emap was getting up there. 405whp at 14.5psi

TeamRX8

iTrader: (25)

very nice Brett

Brettus

iTrader: (2)

Engine has about 20,000kms on it plus 5 or so track days.

AAaF

80% torque just above 3500RPM on a almost 8000RPM engine. And flat all the way up.

Very impressed, indeed....

Brettus

iTrader: (2)

Thanks AAaF , I do have a higher redline than what is shown ....we just stopped it early as I cut boost there anyway. I find the perceptible drop in power pretty handy actually for gear shift timing.

I really want to try the new Garrett G30-660 ..... pretty sure it would improve both ends of the power band even more.

sinkas

didnt know they made a s2 5 speed

TeamRX8

iTrader: (25)

https://www.rx8club.com/series-i-maj...2/#post4907263
.

wannawankel

Wow only 170 hp / 155 ft-lbs is quoted there for the S2 high power. Has anyone ever dynoed a stock S2 (couldn't find it by searching RX8club)?

Brettus

iTrader: (2)

170Kw not 170hp