mr.horsepower

New to both rennlist and Porsche.

I have an 997.1 GT3, which is my first Porsche and the only Porsche I have driven. Except 991 GT3 RS for 15 min.

When I drive below 3000rpm I have som hesitation. Is this normal for these cars?
It does not matter if she is warm or cold.

Sparkplugs are changed and coils. Got a bit better but not running 100% smooth.

Spesifications is 3.9l Sharkwerks engine, 4.0l RS clutch and flywheel. BMC drop in panel filter. Removed side mufflers. Stock headers and rear muffler.

Thanks

FLT6SPD

You have a 3.9 and your asking if the hesitation is normal? Did you buy it with hesitation or have it built and have the hesitation since then? You should be able to answer your own question.

Could be a number of things, did you clean and re-oil your filter lately? Could be your driving style with a 4.0 lwfw under 3krpm? Have you read your ecu for fault codes?

Do you have access to a qualified mechanic to help diagnose?

HarmonyJim

Wouldn't the guys at Sharkwerks be your very first call? Dirty fuel filter, fouled plugs (don't want to go there!), the list is long.

pissedpuppy

lucky you, congrats!

Call Sharkwerks (or email them) they're great guys and very informative

Where'd you get the car? Is it black?

MC 968CS

ngng

you know it's not a PDK like the 991. maybe try downshifting out of 6th gear lol

flsupraguy

Did you ever get this resolved? If so what was the issue?

sharkster

hey there, congrats on the purchase and as I understand it this is your first GT3 (and one with a LWF to boot). The first thing I would say is no 997 GT3 enjoys being lugged around below 3000rpms in the higher gears. It's a free/high-revving motor and to be honest this is even more the case with a LWF installed (from the 4.0). If you have to drive around 3000 and below in higher gears and can't downshift I would suggest maybe setting the car up back with a dual mass flywheel. We haven't seen the car since 2011 when I believe it shipped to Europe so I'm not aware of the service history and/or changes that have been made over the last 8 years and/or the mileage (other than I know it was campainged and raced a few seasons). I do see it has side muffler deletes which we also don't usually have on these cars (that also drops the back pressure and doesn't help for low rpms). There are a few other suggestions I'd be happy to email you if you like but by the sound of it there doesn't really seem to be anything actually wrong etc...

mr.horsepower

Thanks for reply.

I've not done any more searching on this so called issue. Winter is here for full time now. If it's supposed to be like this it's fine by me. Just need to know if it's right or wrong.

I have mailed SW regarding this, but they stopped replying. Probably sick of many questions.

I'm starting a new job as a parts store manager at Porsche 1st March, so I'll be able to get more knowledge pretty soon.

Dan@SharkWerks

Sorry I thought I had answered all of your questions and emails over the last months, and saw Alex had responded to you here.

As I've mentioned it's especially difficult to diagnose your car because you're in Norway and without driving it, I can't even really say if there's actually anything wrong with it. You may be trying to fix an issue that doesn't exist, so I would definitely recommend having someone look it over if you're concerned (or send it here) about the mechanical condition of the car. The car shouldn't have a "hesitation", and when we first assemble and ship a 3.9L, it always runs very smooth. There are a many articles online where journalists comment on how it drives as-good as stock with no hesitations or strangle issues like this. I did give you some things to check and wasn't sure if you did a leak down test, replaced the mass air sensor (these do go bad and usually have errors but while dying they can do weird things), or checked for vacuum leaks but I would probably start there if you're concerned about its condition mechanically. Remember, this car saw a ton of track use and was driven very hard since we built it. Also on a Durametric or PIWIS, were there any engine fault codes or pending codes?

But really this car was built at least 8 years ago by a customer who only drove the car on the track. I'm not sure what parts may have been changed or modified since it was last here, but I know it was not tuned for the fuel you have in Norway or the exhaust with side muffler deletes and a stock center muffler (which changes the back pressure significantly and the low-RPM driving characteristics). I know it's been through other others owners now as well and these are just the changes I'm aware of. This car was tuned for 91-octane with an aggressive throttle map and a lightweight flywheel. If you would prefer a smoother driving street car, this could be accomplished with new programming for the ECU, reverting to the OEM dual mass flywheel, and re-installing the OEM side mufflers. This will make it drive more like a factory GT3 than a modified GT3RS and the throttle can be programmed to be closer to stock. The aggressive tip-in he had for this race car is probably a bit too touchy for the street.

If you want to update your tune file,you can send us the ECU and we can flash it for less aggressive throttle mapping and higher octane-fuel. This will make it more street friendly. Even though you were not the original owner of the car or the engine we built, I would be happy to re-tune it for you and not charge you for this if you send the ECU here (you would just need to pay for the shipping). As Alex mentioned, these cars really don't drive well below 3000 RPMs where you're experiencing this hesitation (and this is more true with the 3.9, more aggressive cams, lighter flywheel, and more compression etc.). If you can drive a stock 997 GT3RS versus a stock 997 GT3, you might notice the behavior is more similar to a 3.9 GT3.

mooty

^ NO one should ever drive GT3 below 7000 rpm.
if you are shifting before 7k (other than backing out of trailer) you are doing it wrong.
sh*t I shoot into my trailer at about 7000 rpm. ask my spotter, haha.

mr.horsepower

Hi, you did not reply after I sendt you the movies.

I'm aware that I bought a racecar. And I'm going to track it as hard as possible, but also drive it to and from the track.
The so called hesitation do not bother me, unless it is something wrong. There is no problem to keep it over 3000rpm. But from time to time we are forced to drive under that here in Norway. Since the car is stored away for the Winter, I have not been able to do any more
research. I have been passenger in a car with very aggressive cams, and an idle that is way more lumpy than the 3.9l. He could not drive under 2500rpm. It was jumping and jerking like crazy. The 3.9 however is possible to drive, but you feel some hesitating. There is no problem getting the car up to speed.

I have sendt an email to EVOMS if is possible to do a mapping of the ECU over Teamviewer when the car is in the dyno at my tuner. He has done this with other US based company before. They never replied.

Regagrding the fuel. We have 95 and 98 RON fuel here. I use 98 RON. Which is the same as your 93MON fuel.

I have complete and detailed history of parts and Things that is changed on the car. It did not go many miles in US before it was shipped to Norway. Cameron that had the 3.9l buildt was the owner before the guy I bought it from. So the history is solid.
There is no bits that has been changed after other than the exhaust. It had the SW track pipes when it arrived here i Norway. And that did not pass the regulations.

I can send you the ECU for a retune, but I do not want less aggressive throttle. hehe

Further communication can be done via e-mail if that is more appropiate.

mr.horsepower

Here is the car now

pissedpuppy

well, good luck with all of your inquiries - I can say the car looks the part, she's a beauty!

mr.horsepower

I can inform that after an hour phonecall with Alex at Shark Werks, the so called problem is not a problem at all.