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@Triple Black Thanks a lot for sharing ! Is the yellow (275WHP) pre and green (291 HP) post tune, assuming yes ? Do you what MFG Dyno this was on ?
Those TQ drops of 25ish FT/LBS at 2.5K and 3.5K RPM's are weird. Couple of the other users have the similar thing, wonder why that is. I think in your case the scaling of the graph plays a part but those are 2 pretty big dips...
Right, I'm assuming the yellow and green are pre and post tune. But this was about 9 years ago. If I was doing it today I'd be more involved and have a lot more info about it. I was a 911 newbie at the time.
The engine really doesn't have much pull below about 4K but then it comes on really strong, which suits my driving style just fine. My new(er) indie actually made a comment that it feels almost like a turbo.
@Triple Black Thanks a lot for sharing ! Is the yellow (275WHP) pre and green (291 HP) post tune, assuming yes ? Do you what MFG Dyno this was on ?
Those TQ drops of 25ish FT/LBS at 2.5K and 3.5K RPM's are weird. Couple of the other users have the similar thing, wonder why that is. I think in your case the scaling of the graph plays a part but those are 2 pretty big dips...
Here is my 996 with 997 3.8 and Dundon Exhaust compared to 996 GT3. My car is blue line (hope that is right....I am color blind.). This is at the wheels so I think you add 15%
There is no way on god's green earth that a 996 GT3 made 269whp
I don't have a dog in this fight BUT I've been looking at rollers and one engine I've seen swapped that has a rep for being a solid one is a 3.2 VR6. Speed Density in TN does them and if I were to ever get a reasonable roller, I'm looking at either a Rotex Supercharged version or adding a single turbo. Very few things sound as cool as a VR6! They have a 1200hp Turbo VR6.
Yeah I would guess it’s an estimated engine hp applied in the bench.
Anyway it’s an awesome ride now with great power and sound with cup uprights with h/r coilovers, gt3 mk2 brakes, full cup exterior, half cage and gt3 buckets.
So basically looks and drives like a cup car :-)
I dont take any credit for the build though as it was bought this way! Will continue to develop it though and primarily make it lighter.
Yeah I would guess it’s an estimated engine hp applied in the bench.
Anyway it’s an awesome ride now with great power and sound with cup uprights with h/r coilovers, gt3 mk2 brakes, full cup exterior, half cage and gt3 buckets.
So basically looks and drives like a cup car :-)
I dont take any credit for the build though as it was bought this way! Will continue to develop it though and primarily make it lighter.
Awesome, sounds like a cool car for sure. Thanks again for sharing.
Nice!!! Makes me want to dyno my 4.0 to see what it's doing.
4.0, stock cams, ported/polished heads by Hoffman, fabspeed catless exhaust. Stock tune but may need to change that.
You should!!
And def need to tune it!
Would be interesting to see next step for me, what would you guys recommend? Is there a lot of gain doing the heads or a lot of dollars for small gain? What did your heads cost?
I think that engine output, including peak power IS important.
If we're going to talk about power bands, flat torque curves and BIG peak numbers, dyno graphs should form the basis of those conversations. Why wouldn't they ? What else should ?
So, let's see those higher than stock HP 996's. Share the mods you've done or not. Share how much you spent to get there, or not. There's a lot to be learned by the sharing and discussion of dyno graphs - I hope some people have seen that first hand on other forums and will help encourage, and participate in bringing some of that community knowledge gathering here.
RULES (we're not savages)
1. No Mezgers, any and all other engines allowed and encouraged, any displacement, power adder or combination of power adders also good to go.
2. Must post a chassis dyno graph, if the dyno MFG isn't overlaid on the graph, please add to your post.
3. If you're a MFG, No Development Mules, must be an engine, or parts combo that you sell or is otherwise commercially available. AND, cost of parts, or engine should be included in your post or readily available through your, or others web store.
2003 manual cabriolet
My contribution to this exercise. Keep in mind that I have no clue what I was doing. I just bought a bunch of bolt-ons and hoped for the best. I remember as a young soldier in the late 70s and the joke was “you bought everything on page 123 in the J.C. Whitney catalog.” My intent wasn’t to get a bunch of horses added, I just wanted better throttle response for random spirited driving. Also some of this was for pure maintenance.
These are my bolt-ons and modifications:
· Coil packs, plugs and wires
· Fuel injectors
· IDP competition plenum and 82mm throttle body (I think that was the size)
· MAF
· Top Gear headers
· Top Gear 200 Cell cats
· Fister mod
· 997 air box with standard air filter
· SAI
· AOS
· Engine mounts
· Transmission mounts
· Oil change
Because of some other things going on, I couldn’t get a great explanation for the dyno results. I do recall being told I got some decent gains in the mid-range. Was it worth it? I don’t know, car drives great and very responsive so I’m happy. I am curious about my numbers, are they decent or did I waste a lot of money (it was expensive), effort and time.
Per Zbomb's reuqest I wanted to share my car with the thread. I have a 2005 Porsche 996 and decided to go with a Flat 6 Innovations stage 2 4.0 motor. I had previously put on all the bolt on's, intake, exhaust, softronics tune, IPD plenum, etc and saw barely noticeable gains via the butt dyno. These are the results of my Flat 6 innovations motor, measured at the wheels of course. The car has: Speedtech exhaust with high flow cat x pipe, 997 air box - BMC air filter, IPD Plenum, and the upgraded motor. The car is completely different and has more power everywhere, by a lot. I do not think the dyno sheet is accurate however maybe due to heat soak potentially? The reason i say that is when this motor hits 6k RPM's it feels like a turbo kicking in and races to the 7500 redline ( 250 up from the stock redline ). It must have another 20 HP jump in that spot or so it seems. The dyno plot however doesn't show that surge at the end. I do have a GT2 deck lid which pumps cold air right into the intake snorkel so maybe on the road that is optimized. The car also keeps getting stronger as it breaks in, it is noticeably quicker and more responsive at 4500 miles in where I am at now verses when I first flashed the tune after break in. If anyone has any questions on this build feel free to ask.
Last edited by 2005 996 C4S; 09-21-2022 at 07:23 AM.
09-05-2022, 08:47 PM
