Must Read - Ultimate dyno tests on Mods

I have just completed comprehensive dyno tests on my CS with a variety of modifications over a 48hr period - same car, same dyno, near as dammit identical conditions (car never left shop). The dyno-pack system is considered to be one of the most accurate available and measures power and torque at the flywheel in accordance with Porsche own strict standards. Parr Auto-sport where the tests were conducted are re-knowned for their expertise in preparing Porsche's (including 911 cup cars) for professional competition. I have dyno'd my car else where and believe that the accuracy/results from this system are as good as can be expected beyond an engine out bench-test. Here goes: 1. Standard Cayman: 293 bhp 2. Cayman + de-snork: 294 bhp (+1) 3. Cayman + de-snork + milltek headers/cat back: 316 bhp (+22) 4. Cayman+de-snork+milltek H/CB +revo stage 2 remap: 321 bhp (+5) 5. Cayman+de-snork+milltek H/CB +revo stage 2+evom filter: 326bhp (+5) 6. Torque - 290 lbft (+40) 7* Standard Cayman + fabspeed headers / tubi cat back: 304bhp (+11) The car was run on BP ultimate fuel (allegedly not great fuel but not bad - although shell V power could add an extra few bhp). You can draw your own conclusions from the above - but lets be honest, this is about as good a bench-mark as anyone is going to get. I had run before/after dyno on revo remap previously and come up with 7bhp net gain after the system had 'bedded in'. Im assuming that the 5bhp gain shown above could be marginally bettered if allowed to be run in. Conclusion - a very expensive way to get 33-35bhp. Have not driven the car yet to determine if its worth it. On the positive side - Parr have test driven it and consider it to be awesome. I will have to wait another 2 days to find out. Car spec as follows: Cayman s Eibach springs / geo set up GT3 carbon seats EVOM / de-snork Milltek H/CB Revo stage 2 re-map carerra classic wheels (from 997 911) / michelin pilot sport cups 295mm rear / 235mm front LSD (on order) Brembo 380mm brake kit (on order) Hope you all find it helpful. Beware of REVO marketing power gains of 15-20bhp. Its absolute RUBBISH. Welcome comments from REVO on this... Terry

Interesting read, thanks for the info.

What I get from this is that by doing headers and exhaust you might see a small gain but the other things are a crapshoot, software or intake or desnork may or may not do anything and definitely not anything noticable. Not really the ultimate dyno test since you should have done each mod individually and also done 2 or 3 runs each. Then done pairs, then combinations of 3, etc etc. I realize this is impractical but it would be more scientific.

Im happy to do it if somebody wants to fund it!! I tried to test the car and mods along a logical upgrade path that most are typically following. There were 3 dyno runs per stage. Doing each dyno on a single mod at a time would have been too time consuming / expensive but appreciate your point. In the perfect world I would have done it...interesting conclusions all the same. Terry

Thanks for the info Terry! I'd love to hear what the manufacturers/sponsors have to say about it all. Of course I'm expecting the typical "well, the dyno has a margin of error of +/- ____ so that doesn't prove anything." haha. I guess we're only to believe the dynos of manufacturers and sponsors. Too bad we can't squeeze out some more power out of our 3.4 w/o a blower. bummer.

Very interesting Terry and not unexpected results I'd say. What was the cost of each of the mods? Thanks for the research.

You said your car was on the dyno but you're stating power numbers in bhp instead of whp. I'm assuming you meant whp.

Terry, I have followed your meticulous scientific research, (including buying 3 exhaust systems............ and the rest) and wonder what rubbish K-ManS puts out regarding increased power output? Sounds like Bo[[ocks to me..........! I will definitely not be shelling out around $2,000 for a Revo Re-Map - sounds that it is not an economic proposition. I'll run my car 5 BHP down on yours, but with it's Uprated Anti Roll Bars, Strut Brace and my 'Sticky' Toyo R888tyres - should be able to see you off! I can pick up the Quaife ATB/LSD on Friday from Sevenoaks, and on the way home around the M25 drop down the M23 to drop it off at Parr if you wish? Just let me (and Parr Motorsport) know.

I have been a member of lots of forums throughout the years, and I don't mean to create any drama or anything of the sort. I just feel like the we get biased information from certain mods/admin on this site. Basically, if the company is a sponsor...they have amazing references, power gains, etc. If they're not a sponsor, it's never-ending scrutiny. I love all the info we get, but i'd like to see products being reviewed by unbiased parties. Example: If Acme Co. were to hook me up on the price of a cat-back, I'd make a very positive thread about them too...you get the idea. I've been sponsored by over a dozen companies and know how the game works. Hopefully, im wrong...and we get unbiased reviews. But I guess it's up to us to dyno our cars and get the scoop. Which sort of stinks, b/c thats the best thing about enthusiast forums...unbiased reviews of products.

IMHO....Best upgrade is to sell the CS and pay the difference for a 997 model 911 S model. Better long term market value plus warranty.

Where's my popcorn? Yum yum.

Great post Terry. I'm doing very similar mods on April 12th and your post goes a long way on what gains to expect from such a system. The tuning company I'm using, Pfaff Tuning in Toronto, has stated very similar results and its great to see them somewhat verified by your personal experience. With a power to weight ratio of 9.06 lb/hp (your Cayman S) vs 8.82 lb/hp for the 997S the driver in the 911 better be a VERY good driver if he/she wants to stay in front of your "mid-engine miracle". Matt

Karel, Do you care to explain the item I have highlighted above? The way I read it you are criticizing something I've said, but I'm not sure what you are criticizing and I want to make sure I understand you before I respond.

I gained +21 hp to the rear wheels with this same setup, just adding milltek headers and milltek cat back. So your estimated crank gain is right inline with what I saw as well from that modification. It is pretty clear to me that the Milltek headers are top notch as well as their catback for power gains. I was a little suprised that the Evo intake didn't add something in addition to the REVO, but I think you said later it gained maybe 7hp which is about what the combination of GIAC and EVO did for me at the rear wheels, since yours is estimated crank gain it would appear you got marginally less gain from REVO + EVO than I did rom GIAC + EVO but certainly within the same ballpark and accounting for dyno differences, etc. I'm also shocked how much the REVO update cost you vs. GIAC since both produce similar results. I gained substantial torque as well, will have to go back and look at the numbers. This is the one I was waiting for and confirms what others have shown on their dynos and that is that the Fabspeed headers are not making significant HP gains and neither is Tubi, the combo here produces 1/2 the gains of the Milltek system for what, about the same price? Ouch! It would have been interesting to mix them with the Milltek units to see individually how Fabspeed and Tubi scored separately, but I understand having a limited $$$ testing budget. Kudos on a job well done and some more good data points! I've actually found that running higher octane gas makes literally no HP difference once your car has headers, etc. on it and is running as about as efficient as it can. I netted a 38hp gain at the rear wheels, so again in the same ballpark, I would put my slightly higher numbers down to the custom tuning on the dyno to max out the GIAC programming and EVO intake. If you look at the Milltek system at $5k, plus GIAC at $1k and EVO at $350, for $6350 full retail you are getting around a 35hp gain which by naturally aspirated Porsche standards is pretty good, I understand that by Chevy Camaro standards it is pretty poor. I think you will find Parr is correct, the car will be awesome! [/quote] I never believe manufacturer claims that is why I independently test everything. As far as REVO's claims it "may" be that they mean ECU tuning ALONE with no other tuning "could" net you something in that range. I've never personally tested the REVO remap but if you've already improved the intake and exhaust sides of the engines to near their ideal efficiency there probably isn't much more than 5-10hp that anyone's ECU tuning is going to get you at that point. Whether or not it would get you more minus the other mods remains to be seen by someone else's tests and I hope another member here does it sometime! Once again, thanks for establishing some more data points that help match up to prior tests and confirm some suspicions I've had about some other products that aren't performing as well on the dyno as some others.

ttommason, how many miles do you have on your CS?

Thanks for sharing the info. I guess 326bhp with LSD should be able to match un-modded Carrera S performance, right? It would be great if you could rank each mod in terms of $/bhp to determine at what threshold the mod would be worth doing.

These results appear to confirm that the Milltek products are indeed generating good gains for sure!

WTF does this mean? Are you for one moment implying that ANY of my reviews of products (sponsored or otherwise) are inaccurate, incorrect or in some way changed because the product was a sponsored product? I thought this issue was laid to rest months ago? Why not go read my response to the original post where I agree/concur with his dyno results because they pretty much mirror what we've seen in our own testing? While I don't know how your "games" work, I do know how our reviews work here and if you are going to make such wild accusations you are going to have to back them up with FACTS or you are going to have to retract those statements.

Ok I heard from Karel and he stated that some of my HP claims in the past are rubbish because they have not been duplicated in the "real" world. I've asked him to tell me which HP claims and what sponsor those claims supposedly benefit. His example was the 13rwhp gain for the de-snork mod. Well let's examine that shall we. 1) I have said over and over throughout that thread that the 13 rwhp that I gained is probably the max for that mod and that gains are likely somewhere between 1-13. Some members have gotten 1, some around 5-7, and myself 13 in that one instance. Have I ever promised 13rwhp gain for everyone? Nope. Quite the contrary, I've said I was surprised by that number and that I think that is probably a max and a result of whatever conditions existed for those dyno runs. But the FACT remains that those results were real and based on real dyno runs done at Imagine Auto. 2) My de-snork gains were without any other mods, no headers, no ecu programming, etc. to already max out hp gains. Other tests where numbers have been lower have involved cars with other mods, so not exactly apples to apples comparisons. I have not EVER disputed anyone else's HP numbers for their desnork checks, I have accepted each and every one and I have encouraged people to do it. 3) Last, but not least WHICH SPONSOR does the de-snork mod HP numbers benefit??? Umm let's see who makes that "mod"? Ummm ME, any products being sold NOPE. Gosh, looks like those implications aren't holding any water....

De-snork gets +1 bhp at the crank, which means less than 1 at the wheel, far cry from +13 rwhp, the only outlier from this forum so far. So practically speaking, it should not even be considered a mod.

Once again someone who apparently doesn't read what was posted. Parr uses equipment that estimates crank horsepower. Ttomasson's engine was not removed and put on a bench dyno (the only way to get true crank hp). I'm not arguing Parr's numbers are accurate or inaccurate as a guestimate of crank hp. I am fully accepting the delta between before and after runs on Parr's dyno as being indicative of the gains one is likely to see. If you make a modification to you car (removing the baffle plate) how can that not be considered a MOD??? Are you telling me that if you installed the Porsche Sports Exhaust (which supposedly gains no HP) to your car that you wouldn't consider it a "mod" because there was no HP gain??? Huh? What about items that may be losing HP are those not mods either? I've said all along, if you want to do the de-snork baffle removal "mod" then do it, if you don't, then don't. I have also said all along that I did it for the sound and that if there is actually any HP gain then hey that is an added benefit. Why are some members here suddenly so down on de-snorking or any dyno results that aren't done 1,000 times over using 1,000 different Caymans to provide some sort of "scientific chart"? I would think people would be happy that he invested his $$$ (or pounds UK) and time to do these tests and report the results. What about saying "Thanks ttomasson, appreciate the efforts" ???

The numbers originally posted mimic the numbers I posted back in June 06 with very similar results. The Milltek headers and exhaust + Evo intake yielded +23 RWHP. Testing done under same conditions before and after (original posting had dyno print-out). Similarly (but with GIAC), we got no real change with ECU remapping after the above modifications. I had noted that most earlier reports either did the ECU first or did not test each seperately. In light of no real benefit from the ECU mods, I went back to the original factory software. As far as the cost / hp. A 23 hp gain and 14 ft.lbs pretty much across the rpm band is very noticeable. As noted by KMan, the Milltek headers (either matched with their exhaust or others) make noticable gains and at least when matched with their exhaust do so without excessive noise. I am always surprised that the criticism about the Milltek system often is centered around their lack of increased noise. I guess not everyone is a fan of Theodore Rooselvelt.

Now WAIT ONE SECOND.... I thought you took a patent out on the desnork! :cheers: I wouldn't worry about any of this. I think your doing a fine job testing stuff and I think you have been as objective as you can since its really just an opinion

ttommason, Anyway you can post the dyno graphs? BTW great information.

Hey, Im missing 20 replies here? Have they been taken off line? I didnt even get to see them - can somebody help with re-instating. I would like to say that according to a trusted source the EVOM works best with the de-snork and that dyno's rarely accurately mimic the air flow through the vents. In this regard I wouldnt be surprised if the de-snork produces more than the stated bhp when blasting around in real world conditions. I think its a worthwhile mod and improves sound effects if anything else. I agree with KMAN that we should be grateful for those of us that support this forum wholeheartedly - invest their own time and money - all with the intent of sharing experiences for the benefit of others. Without this forum life with the Cayman would be 2 dimensional and probably boring. One things for sure - Milltek would have suffered! Look on the bright side - you are probably driving one of the best cars on the planet - and with the mods - an absolute 911 eater for a fraction of the price. I will post the dyno's when I get them later this week. TT

I have 2700 miles on the clock.

" Hey, Im missing 20 replies here? Have they been taken off line? I didnt even get to see them - can somebody help with re-instating ." Did you by any chance not click on page 1?

A bit weird but seems they got 'wound up'. Found them after clicking on link within KMANS post...

I'm not sure what that means??? This message I am typing is #30 in this topic thread, no messages have been moved or changed since this thread started.

I have page 1 which only has my thread plus page 2 which has message 21-30. If I click on the arrow after the quote on message 21 I get to the previous message page...(but atleast I got to read all the messages). KMAN, do you think we could get a formal response from the sponsors on my findings. It would be really helpful for all if REVO, GIAC, EVOM etc could comment. To confirm one point - the total accumulative gain from the revo + evom/de-snork was 10 bhp (although I think this would increase after running in the re-map to around 12bhp or so). What 'net' result did you get from your GIAC software?

Well if you believe I got 13hp from just the desnork and 5hp from EVO and 8 from GIAC it would be 26hp total, but I know that's not right since the combined total with Milltek was 38 at the rear wheels, if you subtract out 21 for Milltek that leaves GIAC + Desnork + EVO = 17 rwhp Which component was responsible for which portion, I don't know.