ExtendedWarranty

Current modifications on the car:
1. Fabspeed Race Header
2. IPD Plenum
3. GT3 Throttle Body
4. K&N Filters
5. Cobb Accessport

https://rennlist.com/forums/gt4/9351...at-it-too.html

The Cobb Stage 2 OTS maps were decent however I've constantly experienced erractic knock correction of up to -9.8 degree of timing predominantly in Cylinder 3 and 6. This would even occur when giving part throttle in 6th gear while cruising on the highway. I chose to use the 91 octane OTS map despite running 93 octane day in and day out. This only ameliorated the problem to a certain extent as I continued to experience knock correction now decreasing to -6.0. WOT pulls on the OTS map were quite safe as it would only pull a max of -4.5 degrees of timing and the car did pull hard. Decidedly I got fed up with it so I opted to get a protune.

Local Porsche tuners around me charged $750 for a road tune and $1000 for a dyno tune. Talk about Porsche tax! I've had highly modified, complex turbocharged cars tuned for less with FlexFuel. It is a complete affront to me to pay $1000 to get a naturally aspirated car tuned for bolt-ons.

I contacted John for a Fabspeed protune ($250). I did a 3rd gear datalog to redline and I e-mailed Steve, the tuner for Fabspeed. Steve made the appropriate fueling/timing adjustments and e-mailed a custom protune map to me based on my datalog.

Impressions:
The car feels noticeably different than how it ran with the Cobb OTS map. The throttle response is a perceptibly snappier and the gains in mid-range torque were astounding! More importantly the car is fully optimized for 93 octane - it sure beats limping around on the 91 oct OTS map with 93 oct in the tank! Redline pulls are breathtakingly savage yet smooth. Finally the protune sure-handedly addressed the problem of the car experiencing high amounts of timing correction in cylinders 3 and 6 that plagued the OTS map at part throttle.

Overall I'm 100% satisfied with the Fabspeed protune and I recommend it to anybody who has done the gamut of bolt on modifications. You spent all the money to get to this point, why not tie it together with a $250 protune cherry on top?

jmartpr

I have less mods on my car ( missing the IPD+TB) but have an exhaust system. Having a ProTune done locally (dyno) was not cheap but well worth the price. The car used to run good before the ProTune but there's a big difference once you Tune it. In my case the car for some reason was very lean (probably a similar case to yours).

cox1974

+1 on the fabspeed pro tune

kahane18

Ditto

Alan C.

If you do one pull through third gear how does the tune account for part throttle response?

ExtendedWarranty

more torque through midrange with protune so more peppy

John@Fabspeed

What an excellent write up and feedback, thank you very much my friend! It was great to work with you on all this and round it out with the protune. Very happy to have met your goals : )

I spoke with our tuner and he has seen that lean condition across many GT4s and 991 GT3s as well. He has resolved that among other things in the factory software that make a noticeable difference as you've felt yourself from your tuning.

Thanks for chiming in! Always nice to see you chiming in the GT4/Spyder convos

You know, I realized yesterday that when we were at NYST I wasn't running my protune. I compared my data from my fastest laps last time with the protune installed and I was down from 122mph to 114mph on the straight. Rookie move! So bummed I was 3/100s from breaking into the 1:37s on a damp/wet track haha.

you need to live closer haha

kahane18

You know, I realized yesterday that when we were at NYST I wasn't running my protune. I compared my data from my fastest laps last time with the protune installed and I was down from 122mph to 114mph on the straight. Rookie move! So bummed I was 3/100s from breaking into the 1:37s on a damp/wet track haha.


I thought you were a little slow...

thigos

Also curious about this...

John@Fabspeed

On vehicles that we have refined our files dozens of times already for popular combinations of products, we only ask for some hard pulls to ensure everything is copacetic. For vehicles with product combinations that are unusual or new to the market and we haven't made many revisions to, we ask for a variety of datalogging conditions including part throttle during normal driving conditions. The 981 vehicles (especially the GT4) is one of those vehicles we have done so many times that at this point various datalogging conditions would end up being redundant. Now if you want to throw a 4.0L in that baby that's a different story haha.

raclaims

Hey John I wrote you guys today
You did my buddies Spyder and it's phenomenal.
Just got my GT4 today and trying to decide what route to take.

kahane18

Follow the NJ Turnpike south to exit 6, PA Turnpike straight to Fabspeeds shop.

Thats what I did.

Trust me you wont regret it!!!

John@Fabspeed

Lol I literally JUST sent you a PM Give me a call at 267 742 3001, would love to chat with you

John@Fabspeed

So I forgot to put my protune back on at NYST the only weekend...lost 8mph on the main straight

MagicRat

Only have a Cobb OTS map on my Spyder at this stage but something nice I feel it does is turn PSE into a performance button. Car feels like it pulls more at low rpm with valves open, which is lovely!