TheAllusionist

Great to see input from others, I have answered PMs to best of my knowledge relating to the Turbo. Unfortunately life has a way of getting in the way, I have mine torn down to head and the turbo to be next, hoping to get to it in a month, but we know how well previous predictions have gone.

I got so tired of waiting on myself that I bought a C5 Corvette (Hatch and last model of pop up headlights) that was completely gone through (except for the engine) and chasis upgraded to C6 Z06. I have all the parts for a monster normally aspirated build once the Porsche is done. Where I am going with this is that keep the faith in your 944s, Chevy copied so much of it for the C5 vette because they had it so right. Two different beast, the LS1 has crazy torque, but my impression is that the nimble 944 Turbo is a scalpel compared to an axe in some ways. They say that the C5 Z06 is the best bang for the buck performance car, and with their horsepower and traction control they may do faster lap times, but I feel like the Porsche is on rails and is going to do whatever I ask it to, even though it is older, it feels more precise and refined. I drove a C8 Corvette last weekend a bit just around a parking lot... buttons to control and shift, cameras instead of mirrors and then I had to figure out how to get out of it, no door handle, a discrete button! LOL

Back to turbo talk! I better order all the gaskets necessary, those with experience can you tell me what those are? I will be installing a dual port wastegate and 3" into 4" (downpipe is stalk size) exhaust following the trumpet principle.

Very excited, just don't have the time and figure when I get it all done I will have to replace the clutch..... Anyway, I am replacing everything except the short block basically, On a 48,000 original mile car in my stealth build and will post when it is on the road and once I get it dynoed. Now if only the planets would align and I can work on it, Step daughters wedding this summer, been working a lot and still doing some bartering, but it is paid for now and maybe I can get dirty in the garage once again.

Nowanker

Hi Allusionist! Haven't noticed you post lately. Don't know if you remember me, but I think you bought a ported head from me off ebay some time back.
Congratulations on the C5. one of the best performance buys around.

TheAllusionist

Nowanker,
Life just gets in the way, but all the kids are now, out, through college and my stepdaughter is getting married this summer, so all sorts of obligations are ending time wise and financially, still have a bunch of parent loans to pay off for that private college....... but light at the end of the tunnel.

Yes, I bought the monster head and modified intake if memory serves me correctly. Unfortunately, the combustion chamber was sized for a 3-liter engine and larger than my 2.5, so I had some other ported heads went through, new valves, springs, titanium retainers.... built and sitting on the bench waiting for me to install the new turbo before installing it and finishing the build. My car is down to the block basically, but haven't started taking off the turbo. I have those awesome heads and the modified intake (seemed to good to separate) stored for a 3 liter build some day. I have ported intake for my current build but those from you were heavily modified for matched runners.....

So yes, with Covid the car scene really picked up, they have opened up our downtown for cruises,etc. so I picked up the Vette as a project car of sorts, not too computerized, so I can work on it, it has all Z06 chasis, C7 big clutch, and all gone through and is ready for the monster NA build, I have all the parts (300 CFM high compression heads, BTR stage 3 cam, intake and headers) so as soon as I am done with the Porsche I will take on that project. So has great handling and should put down 470ish to the wheels, if I spent the bucks for a Fast 102 intake potentially 500ish maybe, but people typically project more than the get...

Anyway, back to the local car scene, I got my step-son into cars to get him out and socializing, he has a 2008 Mustang. It is just a V6 but he/we have done a lot of work on it, converted to dual exhaust, GT rear end, cold air intake and thottle body... and now he and I go to a Coffee and Cars like event every Saturday morning and of course various cruises etc..

What is cool about the Coffee and Cars is that there are a couple of Porsche guys, one has a few 911's a really nice tricked out GT3... And one gentleman has 914, 911,s and a beautiful 956 that Ferdinand? signed his glove box door on when he road in it in what of the big Porsche parades, very cool story about that, Porsche asked if his wife wouldn't mind riding with a Porsche race care driver in car five so that he could give Ferdinand (again, I think that is who it is, Porsche-Piech family member who was head of company at the time anyway.....) a ride in the 356 to lead the parade.... Apparently, it was a win-win, the wife said she had a great time with the handsome racecar driver.... and Kirk had a great time and even went and had beers with Porsche Royalty!

Anyway, really want to get the 944 going for some of those events, nice and unique and not a belly button (everyone has one) car. How are you doing and what are you up to?


P.S. I have gotten PMs from people who got the impression that I was looking for a wastegate, etc.. as I probably didn't word things clearly, but I have everything except for gaskets for the turboe and Lindsey dual port wastegate.......

Nowanker

Nice to hear from you, and that life is getting back on track.
I'm finally wrapping up my 1.8T swap... some clutch gremlins to sort out, but should be good to go with the fresh race motor in a week or so.
I deviated off into Corvette land as well.
Started with a C5 (still have it...), but always lusted for a C6Z06.
One showed up on ebay at no reserve. Stock engine, but a list of expensive track stuff a mile long.
It stalled at a ridiculously low price, and I said aloud "no way this car sells for that!', and threw up a bid.
Oooops.
Cheers!

TheAllusionist

Sweet, I remember you telling me about that! Send info and pictures of your build when you have time! Do you have a build thread?

rt

TheAllusionist

Now that I think about it, I got my Vette because I was jealous of you!!!! It is all your fault! LOL

Doyle623

I previously asked for feedback on the Evergreen Raptor turbo upgrade.. Well, this past weekend I was lucky enough to drive "MWC951" 's car, which has a Raptor K27/6 and supporting mods (Vitesse MAF, 3" exhaust, ported head, electronic boost controller, etc.). I was blown away with the responsiveness and how hard the car pulled (and sounds amazing). I used to have a K27/6 7200 with similar mods and was not even close to this performance of this thing.

TheAllusionist

Thanks for sharing input and insight!

SirLapsalot

I've seen a few references here to achieving full 1.0Bar of boost by 3.0k rpm. Anybody have a data log showing that?? Curious what gear, dyno or road, other mods, etc. I'm skeptical it's possible to achieve 1.0Bar by 3krpm and hold all the way to redline with an old school based thrust bearing turbo, but multiple people are saying it here so maybe it's actually possible??

I'm running a K27/6 "Raptor" from Evergreen and I'm not seeing full boost until 3.7-4.0k rpm... (One caveat/excuse here is that I can in-fact hear a slight exhaust leak, however I'm not sure yet if it's actually pre-turbo and it's certainly not large enough to increase lag by 0.8k rpm -1k rpm…)

Regarding back pressure, here's a data point for reference. Ratio is ~1.7:1 by redline on my car:

Specs are below.
Engine internals: Stock
Headers and cross over: Stock
Downpipe: Stock
Downpipe back: 3.0" straight through (No CAT) to Borla Muffler
Turbo: Evergreen K27/6 "Raptor" upgrade
Boost pressure: 1.0 Bar
Wastegate: Turbosmart 38mm
Boost Control: Electronic by standalone ECU - PID is setup to maximize time to target without ANY overshoot, suppose I could improve spool by 100-200rpm max by allowing some overshoot while ramping to boost but again, that's not 3000rpm.
Gear = 4th
Dyno = DynaPack hub dyno
Ramp Rate: 500rpm/sec

I've confirmed my spool performance is the same on the road


*p.s. MGP in above screen shot is intake manifold pressure in gage pressure.
**p.p.s. Not that it's important data for this example but the waste gate position signal above had an error at the time of this data log. Off by a factor of 10. If displayed in meters the decimal place needs moved one to the left, or more sensibly it's been changed to mm now. Anyway.

Droops83

@SirLapsalot , your setup is almost identical to mine, except I do have a 3" downpipe from the turbine outlet to the main 3" exhaust section (I think it is SFR). I would be willing to bet that is affecting spool in your case. I need to dig out my PC laptop that I use for tuning, but I have some logs showing MAP vs RPM (among other things), I'll have to dig them up. I definitely see 1.0 bar of boost by about 3300-3400 from what I remember.

Thank you for posting your exhaust back pressure readings, I have a fancy backpressure sensor and EMAP damper and coiled copper pipe sitting under my desk at my shop, waiting for me to install it and wire up the sensor. I have too many cars, and I never seem to get to the 944 Turbo! The #6 hot side is tiny, and I have the "prototype" of the Raptor K27/6 from Charlie; he did a lot of porting of the turbine housing, not sure if he has refined his technique. Nonetheless, 1.7:1 at redline with a tiny hot side housing and stock headers and downpipe is not too shabby! My eventual goal was to upgrade to the K27/8 version for track use, but I hardly ever make it to the track anymore . . . .

SirLapsalot

OK, 3400rpm seems more reasonable. With a downpipe maybe I would be closer to that window.

Frank@Work

AugTronic ECU with EBC, stock downpipe, AFM replaced with open pipe (MAP sensor), stock intercooler (pipes), same turbo (Evergreen Raptor), 3" exhaust:

750mBar at 3000 rpm in fourth gear.
1000 mBar at 3385 rpm in fourth gear.

I have setup the boost curve in a way that a "gradually" increase boost pressure down low to prevent an overboost spike. I think it is possible to get 1000 mBar sooner than 3385 rpm when I max out the boost buildup.

SirLapsalot

Very nice. Got a data log of that you can post?

I'm at basically max EBC duty, WG fully closed, and only seeing 300mbar @ 3000rpm.

SirLapsalot

I'm also running fairly aggressive timing off-boost/low-boost which is resulting in low EGTs. So certainly less timing would up my EGT a bit and likely help pickup some spool. May go back over my timing in this area and confirm the effect to torque versus EGT and subsequent spool. Not holding my breath for a major revelation there though.

Droops83

Yes, my timing map is somewhat conservative, with higher EGTs than I'd like to see. If and when I ever make it to a dyno, I would like to play around with that balance and see what works best.