480 HP/ 476 ft-lbs on CIS @ .96 bar!

[porschett]

408 RWHP / 405 RTQ (with 15% drivetrain loss)

So finally got the beast dynoed with the RPM switch/solenoid mod that Brian Leask (bleask@cox.net) designed. Check out how flat the AFR curve is now. It's like EFI!

WUR Boost enrichment is set at 2.2 bar. I'm going to lower it to 2.1 bar to richen it a bit top end. Right now, it's around 12.5 AFR around 6K.

The blue run is before the RPM switch/solenoid mod. The red run is with boost enrichment to trigger at 4400. Notice how much smoother the HP/TQ curve is in mid range. No overich stumbling. I've gained 30 RWHP between 2800-3600! Incredible.

Mods:
36mm port
K27
1 bar spring (actually getting .96 bar)
IA fuel head
C2 cams
C2 bypass assembly
Baileys diverter valve
Borla exhaust
goingsuperfast.com headers
Blownsix Design 965 IC
Custom powerflow intake
ARP head studs & rod bolts
Nology wires
Car corner balanced and weighed in at 2750 w/ 1/2 tank of gas

[RarlyL8]

Fantastic!
Can you go into detail on this RPM Switch mod? Is it more than his custom WUR? What does he charge nowdays for the custom WUR?

[porschett]

I think Brian has a package deal with the RPM switch/solenoid and custom WUR. You may need to contact him for more details (bleask@cox.net). The switch/solenoid is way cheaper than the custom WUR.

Depending on your setup, you can swap out modules at different RPMs. I had it to trigger the boost enrichment at 4600, but saw the AFR start to go lean. So we made another run with the 4400 module (takes less than 2 sec to swap out) and saw the positive results.

[Mr Beau]

At 13:1 AFR it appears another rebuild will be in the cards in the not too distant future... That's just too lean for the power being produced. Even 12.5:1 wouldn't be safe as far as I'm concerned.

[porschett]

Yep, I realize that. That's why I mentioned that I'm going to increase fuel by lowering the boost enrichment pressure at the WUR.

[DW SD]

Congrats David!

Doug

[azasadny]

Beautiful car!!! Wow!

[WydRyd]

Awesome figures! Congrats

[beepbeep]

This is a real-world example of how leaning out the mixture sometimes can provide more power. There are many on Pelican Parts that firmly believe that "richer is better". I presonally don't think you should go much further down than 12.6 while on boost.

AFR curve on display is perfectly OK to me and I don't believe that "At 13:1 AFR it appears another rebuild will be in the cards in the not too distant future".
Car has perfect AFR curve where it matters: from 3000 to 5500 RPM. It reaches max power @ 5400 RPM and keeps ~ 12.5 troughout majority of boost part of rev-band.

Breathing efficiency falls off over 5500 RPM (probably due to CIS) so I don't think engine is risking detonation even if revved past it's power peak from time to time. Only thing I would do is to richen it a bit after 5200 if possible, otherwise it's OK.

[Mr Beau]

OK, but what are the EGT's at 12.6 AFR with a 1 bar of boost? 1600F? 1800F? more? Extra fuel is needed to keep temps within acceptable limits. Too much heat can lead to preignition from the exhaust valve getting too hot. The life of the exhaust valves, guides, headers, and turbo are all reduced when temps get too high.

[beepbeep]

Originally posted by Mr Beau
OK, but what are the EGT's at 12.6 AFR with a 1 bar of boost? 1600F? 1800F? more? Extra fuel is needed to keep temps within acceptable limits. Too much heat can lead to preignition from the exhaust valve getting too hot. The life of the exhaust valves, guides, headers, and turbo are all reduced when temps get too high.

EGT varies with backpressure, boost, ignition timing, turbine sizing and heaps of other parameters. EGT's are not visible on the graph so making blanket-statements of "13.0, EGT is too high" doesn't work. Only way to know EGT for sure is to insert a probe just before turbine.

[RarlyL8]

Exact or perfect A/F ratios and tuning simply do not matter in a street car, there is a range of values that are acceptable for longevity. You are not on boost long enough for heat to build up. Folks on this board tend to get lost in perfection and miss the big picture. A track car and a street car are soooooooo different in setup that you simply cannot apply the rules of one to another.

[SLO-BOB]

Originally posted by RarlyL8
Folks on this board tend to get lost in perfection and miss the big picture.

D'ya think?
Probably the most true statement I've read today. That said-

Nice work Porschett! Thanks for sharing vitals.

[porschett]

I forgot to mention that at dyno time, I was running MS109 and was tuning for max hp and tq.

VP MS109
• Motor Octane: 101
• R+M/2: 105
• Research Octane: 109


With that said, I downloaded my logs from my LM-1. At full boost and 6000 RPM, my AFR never went over 12.6 even though the dyno says it's close to 12:8. I'll err on the save side and go with the dyno's readings.

I agree with Rarly8 that it's not a race car and probably won't see anything over 5000 RPM on the streets. I rarely boost anyways. It's just good that the HP's there in case I see a Z06 ;P

Normal setup for the car will be .8 bar on 91 octane. So I think the current setup should suffice.

Glad beepbeep "approved" of my setup...oh wait...didn't he have to rebuild his motor. LOL

[Craig 930 RS]

Any updates?

[asphaltgambler]

And people think you have to install a V-8 to get that kind of power

With CIS that HP / TQ output is bad-as! You go boy!