944obscene

Not sure if it was mentioned (skimmed through the thread on my phone), But cams will make a big difference with each application.

Also I was going to look for turbos that work well for other 2.5 engines until I realized that my Porsche mill is a single cam unit with very different properties than most imports. instead of a 1.8 or 2.0 liter with a log style or short equal distant manifold, revving to 8k, I had a 2.5 with a LONG exhaust header (effectively). All that plays a difference. I know the 968 and S2 based motors with dual cam heads are a bit different, but I thought it might be worth mentioning since it seems that I've seen a lot of built motors that work well with different ar's, hot housings or compressors. A comprehensive data sheet would be nice. Turbo sizes and specs for different builds and setups. Wasn't there a such a thread?

refresh951

s14kev - It would be great to see your results! Onspeed has installed with #8 hotside and it would be great to see his results as well. Looks like both of you are installing with the M-Tune.

onspeed

MBC set at 16psi, I hit that at ~3,000-3,200 RPM.

onspeed

I'll get you more exact measurements tomorrow. Couple issues still need to be worked out, but overall car runs well.

Scott H

Wonder if a Borg Warner Bulls-Eye S252 or S256 would fit the oil pedestal on our car. They have 3" inlets with the map width enhacning ports. They would equate to GT3071 and GT3076 respectively, yet seem to flow a tad bit more on the far end of the map, not that any of us are going to be flowing anywhere north of 50lb/hr. They achieve similar spool up compared to the Garretts, only the BW has no ball bearings, and can be rebuilt for cheap (look up rebuilding a Garrett BB, you can't, you buy a new CHRA for $500). Borg Warner acquired KKK years back so you can say that you're staying with spirit that Porsche intended, you know, if that's your thing.

That said, I was real close to buying a Turbonetics CBB TO4E Super 57/F1-57 turbo, but I'm just going to rebuild ye olde' KKK and have some fun on the cheap for a while. If I want a bigger/better turbo in the future, well, then there is nowhere to go but up, but I think I've worked out a setup that should keep me happy for a while

onspeed

At WOT in 5th, starting at 2,000 RPM I saw 5 PSI at 2,200, 10PSI at 2,600, 16PSI at 2,800. Keep in mind this is in Houston, TX, which is basically at sea level. Hope this helps in your decision-making. Garrett DBB T04e, .50 trim, #8 hotside, stage 3 compressor wheel.

refresh951

Thanks Onspeed - that spool up looks better than my K26/6 as I was getting to 16 PSI at about 3200! I am pretty sure this is the direction I am going, now just #8 or #10 hotside? Any plans to go to the dyno?

onspeed

Lag seems just a tad more than the k26/6 I took out, to be honest. On a similar type of test, I would get 16psi at 2,600 RPM. Spool up is definitely quicker on the Garrett though, like on shifts.

No plans for dyno, unfortunately. For comparison, I pulled away with relative ease from a convertible C5, LS1 Corvette the other day, in a third gear run. Not sure on the modifications, or if it was a autotragic or 6 speed. Just a random encounter on the highway.

refresh951

Onspeed - Were you running the stock airbox with the K26/6 before you installed the M-Tune?

onspeed

Negative. I've honestly never driven an AFM 951 before. My father installed an Autothority MAF kit in '93. I installed a MBC, 38mm Tial, and a 2.5'' test pipe less than a year ago. Rogue's kit didn't help with lag to be honest. It did make the transition between on boost and off much smoother though.

Even with the stock exhaust, stock wastegate, and just a Lindsey Boost Enhancer with the cycling valve, I don't think it took that long (3,200RPM) to get full boost.

refresh951

Stuff I have read shows that removing the restriction of the airbox and AFM improves the spool up. That could be some of the reason that you were seeing 16 psi at 2600 with your old setup and I was seeing 16 psi quite a bit later (3200).

Rogue_Ant

Yep, getting rid of the AFM is the main cause of improved spool-up. Going from MAF to MAF most likely won't change spool-up much. However, power/torque during spool-up is really where my Tunes shine! This translates into a smoother transition and much more linear power delivery.

onspeed

This.

Car definitely runs smoother with Rogue's tune. Part throttle response is considerably improved, and WOT is much smoother with his tune. Some like this, some don't. I personally thought the "on/off" switch was lots of fun.. although I'm sure my engine would beg to differ if it had hands to type with. AFRs are much better than the autothority tune, and plus I can now change boost (and a turbo) as I please without worrying about running too rich or lean.

Just wanted to make it clear that I'm giving my honest opinion about how I feel towards his tune. I don't give a "kiss your ***" review, unlike some I've seen, but I will say that I do not regret going with his tune. It's great, he was/is very helpful and informative, and the car does run better with it. I've only had experience with the APE Stage 2 tune and Rogue's so I won't comment on other vendors, but his tune is miles better/more sophisticated than the dated autothority I was running.

This is getting off-topic. So no more posts please unless it relates to turbos.

George D

Tuning is more important than turbo selection within reason. A good tune will spool the SAME turbo 500rpm sooner. Turbo selection is important, but it doesn't F****** matter if you don't have the correct fuel, timing, and a long list of other "little" issues correct in your Motronic chips, or piggyback. Trust me, tuning a stand alone system takes HOURS of effort...

Hats off to Rogue. Trust me, he isn't making much money selling his kits. I know he did this on his car to make it run better first. There is no business model on earth to state his efforts otherwise. I believe he loves these forgotten killer cars, and would help anyone wanting to get their 951 up to snuff.

refresh951

Onspeed, i think all of this is on topic, as I really am just trying to compare apples to apples in making a turbo selection. I do value your feedback on the Garrett turbo.

That being said, as far as "kissing ***" you might have that confused with appreciation!