Recommended Turbo for 930

[CreatuR]

Looks like the K27 may be on its way out...checking it out over the weekend. At any rate, what turbo would you guys recommend? Debating a rebuild of the K27 or another MFG with modern technology. Below is the car's specs:

3.4L
Electromotive XDi
Kokeln
Factory Wastegate w/ 1 Bar spring
HKS Controller
Modified fuel head
B&B Exhaust
CIS
Group B cams
NGK H7

[RarlyL8]

Nice car!
Lots of opinions on turbos. You can fab so many options are open. Obviously the turbo needs to match the build. You going for top end or quick spool?

[CreatuR]

quick spool!

[RarlyL8]

At what engine speed does your setup reach full boost now? What would you like that number to be? Where is red line or rather where do you shift?

[CreatuR]

I used to get a pretty quick spool with a distributor with a modified ignition curve. However, I wasn't too thrilled with the sound I got at the top end. Full boost was around 3500RPM. On street tires, the vehicle would get completely sideways full in on second gear and slip quite a bit in third.

However, since then I've switched over to an XDi unit to clean up the top end and haven't figured out the proper timing. Therefore, I'm back to the old 5000RPM at full boost.

[mark houghton]

What, you don't get full boost until 5000? Or do I misunderstand your post? If true, that aint right.
My car has never gotten sideways in second, or first gear for that matter. But then, I don't get full boost until around 3800 because I'm "still" running (Cole, be gentle) with the 7006 K27. That lets me get my road speed high enough so as not to break traction when things ramp up. Then just hang on for your life. Of course, I don't have quite the mods you have.

[cole930]

Be gentle: damn kids never do listen to their elders !!!!!!

YOUR GROUNDED UNTIL YOU GET THAT DONE !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[RarlyL8]

Something isn't right, even a 7006 is on full boost before 5000rpm. What K27 do you have?
With headers, proper fuel/ignition curve, etc you should be at full boost by 3000rpm with any turbo. Those cams may be hurting you some.

[wjfk32]

Originally Posted by mark houghton

What, you don't get full boost until 5000? Or do I misunderstand your post? If true, that aint right.
My car has never gotten sideways in second, or first gear for that matter. But then, I don't get full boost until around 3800 because I'm "still" running (Cole, be gentle) with the 7006 K27. That lets me get my road speed high enough so as not to break traction when things ramp up. Then just hang on for your life. Of course, I don't have quite the mods you have.

I concur...
Had a problem awhile ago with the distributor/coil--(missing)no pull. (chk distrib-setup-vac lines-timing-etc)
Similar set-up---My boost comes in about 3200-3500-depending on weather conditons..Colder the better..1bar spring--hit 1bar now and then..holds on top end.--Freakin world of difference going from 80+degrees to low 70's
My 915- 3rd gear--3000rpm--sweet spot to 6000rpm.. K-27-7006 & SC-Cams--nice overlap--lopey/idle..
My car-Top end rebuild-rings-bearing-valve guides-etc-MSD6AL&(MSD(new-epoxy) Coil-HKS/AIC-Open/box intake/magnecor-wires/..No A/C unit..front oil cooler-braded lines.
The funny thing I just changed my belt/oil&filter change..And now the car feels much more agressive--and runs with more charge.. The Old belt was a little loose..didn't think it would make just a BIG DIFFERENCE, but it did.. I knew I had a problem downshifting--heel/toe...revs/slipping---were a little wacked..

Walt

[RarlyL8]

The 915 makes a huge difference in percieved power. My 7200 will fry the tires in 1st and 2nd. In the winter with cold tires and cold dry air you gotta pay attention. But again that is making 300+ft/lb torque from <3000rpm to redline.
We need to ID this turbo.

[mark houghton]

So this morning (perfect conditions, about 56 degrees outside) during my morning commute, I did a couple tests. Second gear, steady 2000 rpms until I'm outa the city limits....radar detector on....I put the pedal to the metal. Hold it....hold it.....and full boost hit at about 3800 (hard to tell 'cause things happen awfully fast). Then repeated the test but in 3rd gear, starting at 2000. Peak boost achieved at about 3600. I may repeat this test this afternoon, but starting at 3000 rpms.

Again, this is with a 7006 and with 12 degrees static advance timing being trimmmed down progressively eventually back to stock settings as boost builds.

If I can convince the Old Guy to give me back my keys and if I can get my dead-ass motivated, I'll slap on the 7200 sitting on the shelf. Gotta order a couple gasket thingies first.

I do like the excitement of the 7006 'cause you're forced to run at higher rpms to get the performance, which makes you feel like you're driving a race car all the time (which isn't necessarily a good thing), so I'm really interested to see the difference between the two turbos.

[911TT33]

There are newer, quicker spooling, and more efficient turbos out there these days that would see full boost 1k rpm earlier, giving you a fatter power band

[drmatera]

Mark touched on a good point. When you guys say "should make full boost by 3500rpm" you must mention what gear you are in because that makes a huge difference. Also without datalogging you could be off by as much as 300-400rpm because you really can't watch the boost and rpm needles precisely at the same time to give an accurate reading.

Now, I happen to have the ability to datalog. There is a substantial difference in boost response vs gear.

[CreatuR]

Yep, the CAMs certainly are the issue. The engine I have in this car is from someone's previous build. Kinda adopted their strategy of top-end power. I have some proper CAMs and twin plug heads with titanium bits sitting on the shelf. I just don't have time right now to install them. It will be a good winter project.

[CreatuR]

Well, I found my whistle issue. After having some time last night to take a closer look, this is what I discovered.

[CaptainCalf]

plug that sucker and let's hear a report!

if that doesn't do it for ya try one of these:

[wjfk32]

Originally Posted by mark houghton

So this morning (perfect conditions, about 56 degrees outside) during my morning commute, I did a couple tests. Second gear, steady 2000 rpms until I'm outa the city limits....radar detector on....I put the pedal to the metal. Hold it....hold it.....and full boost hit at about 3800 (hard to tell 'cause things happen awfully fast). Then repeated the test but in 3rd gear, starting at 2000. Peak boost achieved at about 3600. I may repeat this test this afternoon, but starting at 3000 rpms.

Again, this is with a 7006 and with 12 degrees static advance timing being trimmmed down progressively eventually back to stock settings as boost builds.

If I can convince the Old Guy to give me back my keys and if I can get my dead-ass motivated, I'll slap on the 7200 sitting on the shelf. Gotta order a couple gasket thingies first.

I do like the excitement of the 7006 'cause you're forced to run at higher rpms to get the performance, which makes you feel like you're driving a race car all the time (which isn't necessarily a good thing), so I'm really interested to see the difference between the two turbos.

Nice write up

Cams proabably would be your secret sauce waiting..
For me - I have Euro headers-no cat-..Quick spool is right there with a nice chill in the air..I have my car dialed in for top end..60mph to start and higher is my kill zone to boogie..I don't want my 1st&2nd gear to go bust.....Stop light to Stop light boost is just putting more stress on parts that I don't need..

The best part if some clown wants to challenge me, I don't entertain-street battles..Sometimes clowns-follow me on the hwy..Then...I just relax..cruz in 3rdgear or 4th--wait for right rpm to be in..Chk for open hwy..Then UNLEASH-..I usually get one of these looks after i shut it down...

[mark houghton]

Originally Posted by wjfk32

Nice write up

Cams proabably would be your secret sauce waiting..

Got a set of SC cams that someday I'll install. Those, the 7200, and perhaps a set of headers someday would be all that's left to consider.

[wjfk32]

Originally Posted by mark houghton

Got a set of SC cams that someday I'll install. Those, the 7200, and perhaps a set of headers someday would be all that's left to consider.

Trying to fight the MOD-BUG.. Bad sting bite.....Looking at an intercooler & one of those BorgWarner-billet babies....

Mark - U got cams waiting, I would go with one of those BW'turbos--That will take u to ANOTHER LEVEL INSTANTY..Why play around with 7200--So boost will come in a little sooner...( a little xtra sugar )...OR give me the freakn kilo..

[Thierry25]

Originally Posted by drmatera

.... There is a substantial difference in boost response vs gear.

That's completly true and logical !