Engine Modifications???

This is really an extension to a previous thread re: Evo Intake ... but want to take it just a step further. Is there any real HP and TRQ increase in any bolt-ons besides a supercharger. I.E. if I get headers, hi-flow cats, intake, mufflers and chip - what can I realistically expect to gain???? Like someone said in the other thread the X51 package includes cams, heads, intake manifold etc.. and gains only 25HP - I do not think there is very much more anyone can squeeze out of this baby - if you add the HP claims by the product manufacturers the above bolt-ons should add in the area of 50-70HP ???? Are we all being taken for fools??

Well you know what they say, a fool and his money.....

John There are some things, that can be done to increase HP, But our cars are tuned very well from the factory, thats its almost inpossible to get the gains they are stating with out adding a supercharger.You will only be taken for a fool if you do these mods. Maybe if you do the intake ,headers and flash the DME, you might see 10-15 hp.....yea thats it. Aak me how i know..

I upgraded the Following a couple of months ago - VFLOW Cold Air Intake, Fabspeed T504 Headers and Tro Flow Mufflers and the Chip Upgrade - Overall Gain Maybe 20hp - MAYBE - But I love the Output Sound and the better throttle response. Is it truly night and day - NOPE (Except For Exhaust Note).

the GIAC flashes work better on the 3.4 motorthan they do on the 3.6; best on the 99 3.4 motor with NON-egas.

they make power. do before an after dyno runs. if you were in AZ I would put you on my Dyno for free to show you. Better air flow, tuned fuel, equals HP. Whether it is bottom or top end is different. But it will add power. You will notice this from different elements. But 1 or 2 bolt ons will not net you the crazy results as the complete package will when you tie the puzzle together with a ECU. Doing a intake, mufflers, and header package with the ECU reflash tuned properly to those components will net you about 20-30 HP guaranteed. Or send the stuff back!!!!!!! There is a big difference in price compared to a supercharger. But at the same time, the supercharger is useless with out a better flowing exhaust and tuned ecu, see the overall picture. PM me for some more details.

True That Dan ! P.S. How's your back amigo ?

When will one of the tuners post some engine dyno numbers................................................................. ........................................................................ .........................................................don't hold your breath.

I can't speak for the 3.6 cars but with the GIAC flash on my 99 3.4 I certainly felt it beyond 4000 rpm... car felt eager and pulled harder... especially from 4500-7000 rpm... just where you need it when your racing... also the lethargy of the 3.4 @ 3000 rpm is gone - slightly more pep... for the money I think it's a great upgrade... certainly 20 hp isn't going to snap your neck back but your engine will behave in ways it hasn't before and you will notice this behavior on your favorite roads.... I'm going to do some stopwatch runs when the weather gets a little cooler and I'll post my results... as for headers... I don't know if they give you anything at all... I'd like to see some before after dyno numbers on the 3.6

I'm not an engine expert but I spend a lot of time with folks trying to squeeze out another .1 second. The issue with getting more power out of our engines is not that they are already at their max. A n/a 3.6L flat six can easily make 400 hp. I think the issue is that the engine is pretty well balanced so there is no magical restriction that you can just remove and make instant hp. If you believe the claims that you can just change the intake and make 20 hp then you have to believe that Porsche made a 340 hp engine and then put a crappy intake on it that pulled it back to 320. Does that make sense? I know the story is that they put it on to meet Swiss noise laws. Give me a break. Does anyone really think they took 20 free hp out of the thousands of cars sold worldwide to satisfy the 200 sold in Switzerland? The reason the X51 is the only real way to get more power out of our n/a engines is that it improves the efficiency of the whole engine. I'm not saying you can't make any "spot" improvements but to think you are going to find a significant imbalance or a restriction that the Porsche engineers didn't think of is a little naive isn't it? Just an early morning rant. Feel free to ignore it. Jim

All the bolt-ons will give you about 20 HP, all at high RPM, at the expense of losing some low-end TQ. If you're looking for a place to start modding, swap out the stock springs and shocks for some H&R springs with Bilstein HD or Sport shocks. Coilovers are great too, but unless you're planning on changing your ride height regularly or using the car exclusively as a track toy they're a waste of money.

What Jim said

I totally agree, suspension mods will give a much more noticable improvement. FWIW RoW M030 rocks on a 996.

I did all that whiz bang stuff on my car and was on the verg of the ECU remapping when I pulled the trigger on the SC. Wow what a differance. I think it is getting faster all the time. The exhaust was the best mod before the SC because of the great sound, but I really could not tell any significant differance from the intake, headers, exhaust. I would love to do suspension but I am too low for around here already and just have no good place to autocross or track my car. I can't see spending 14k for 25 hp with the X51. Now the new 997S X51 is supposed to get the car to 381 hp. That is more like it but how close would you be to a new turbo? Will

Did all this stuff to my last sports car(ricer) and there was no difference at all.

What you did on previous cars has no bearing on these cars. For example, on my Supra TT an intake, and straight through exhaust (and a slight increase in boost due to reduced exhaust backpressure) yeilds 50 rwhp. It's all about the individual engines, their efficiency, and any compromises the factory made. Based on the volumetric efficiency data I've seen on my 3.4, I can't imagine picking up more than about 10 rwhp across the board (without the use of forced induction). Of course if you shift the torque band to a higher rpm you'll see higher horsepower numbers at the expense of low end torque.

And therein lies the rub. So many folks do mods to their NA Porsches and make them less potent for real world driving. Now if you are a track junky and don't mind the decreased reliablilty (and possible voiding of warranty) then go for it. You may pick up a tenth or two. Although I can see replacing the exhaust for a more vocal one as the stock exhaust is too sterile for my tastes.

A car with the mods mentioned is NOT less potent in every day driving... quite the opposite actually... The same people seem to keep speaking out against these mods (ecu, intake, headers, exhaust), but few of them have actually tried for themselves... You couldn't pay me to switch back to stock... Here is the key though... be patient and pick up the parts used (other than ECU)!!! The gains are very nice for $2k... at a $4k investment, it would be a stretch... Be smart about your upgrade plan and you will not be disapointed in the end.

If you have had good experiences on used stuff, then "CHEERS". My experiences have been horrible - it's either misrepresented, broken, used to death or I am dissapointed in some way - rarely am I happy with a used item. My experience has told me to buy NEW because if you don't - you will end up paying for it anyways. I should say that being up here in Canada, the used market is somewhat limited so I have to buy from the U.S. - with that said its not like I can drive down and examine the parts - so I end up buying sight unseen - and TADUM - dissapointment.

I agree with John and others...there's no way to be sure about "add ons." I don't know what your motive is to strap on another 50-70HP. Are you tracking the car? If so, how long have you been tracking? If I were that interested to "take the plunge," I would certainly Dyno the car first. Then you'd have a base to compare. However, before I'd rush around trying to go faster, I'd have to be convinced that my skills' levels were appropriate for the additional speed. Keep in mind getting around the track fast, if that's your objective, is a function of more than greater HP. Good luck and keep us posted.

In the latest Flat-6 a french Porsche mag, they stated that RUF has now made a bolt on supercharger kit that gives 60 BHP to the 3.4 engine and likewise for the 3.6. Cost is 13k euros.

Wow, 60 additional horsepower compared to the proven 100+ hp gain of the EVO for the same price. I feel compelled to swap out the EVO system fpr the unproven RUF system. RUF, as always, is behind the curve and is again counting on therr name recognition to suck people into buying inferior systems for higher prices. I thought RUF was the one that a few years ago was quoted as stating that "to supercharge a Porsche would forever distroy a legendary automobile". I guess they had a change of heart? Maybe following the money rather than the legend??? But, there are always buyers, such as those who pay $300 for a Porsche Certified oil change.

Strong words, I don't know what you have against Ruf but say their products are inferior and unproven is very biased. Do you have some data to back that up? Have you seen the Ruf SC install? I think it looks very slick as one would expect from Ruf. IMO if you are comparing Ruf and Evo there is no contest, I'm sure you may feel differently. I wonder who will still be around in 10, 15 or 20 years? I will agree with you that Ruf stuff is way overpriced.

I couldn't disagree more. Here's my story: First off, I bought my 996 used (couldn't afford a new one, heh). I bought a barely-used set of Fabspeed mufflers from another Rennlister off of eBay for $700. He has a GT3, seemingly plenty of $$ and was trying one exhaust after another after another. I then bought a set of (new) Fabspeed headers at a blowout price of $990, also off of eBay. Then I bought a used EVO cold-air intake kit from a guy who was trading in his C4S and needed to put his stock intake back on it for the dealer. I think I paid around $175 for a $379 item - also off of eBay. After it was installed, you would've never known it was "used". He included every screw and washer in a zip-lock baggie. BTW, both of my Porshes were bought off of eBay as well. My point is, that if you put some effort into it, used parts are not a terrible way to go. I'm more of a smart shopper than anything else. My funds are limited and if I paid top dollar for everything, I wouldn't have all that much. Now as to the topic at hand, I love the mods. As someone else stated... you couldn't pay me to put the stock parts back on it. There was a slight decrease in the bottom end (and I mean very bottom). But the mid-range and top-end is so much better. We only have two lane highways around this island and it really sucks to be stuck behind someone doing 50mph along with limited "windows" for passing. I drop it into 3rd, hit the yes pedal and in no time at all I'm doing 90-100 for virtually incredible passing accelleration. My wife's Boxster S is really peppy on the bottom end, but feels anemic in this very same situation, as did the 3.4 996 before the mods. Not bad for a $2k investment. Next up, the ECU modification!

Steve, I see you have a tip... your really gonna like the GIAC upgrade... it's gonna pull everything together and give you even more top end from beyond 4500... talk to Steve Weiner at Rennsport Systems - he also has an upgrade for your tiptronic ECU as well. Do you find the EVO filter works well in hot weather... from what I heard it works best on cool days...

Stevo '99 If you have had good used experiences that is great - I don't seem to have that luck at all.

I've had pretty good luck with stuff off the net as well... bought my PSE for real cheap and also the T-equipment tips for next to nothing.... here is a tip: on eBay I always make the transaction through paypal.. this way it is a recorded purchase through EBAY that they can arbitrate if it comes down to it... you have to be careful of sellers asking you to forward funds directly to them and not via a 3rd party like paypal.... doing this kind of takes the responsibility off EBAY to act as an ombudsman if something does go wrong.

*budding in* All CAI's(cold air intake) work better in cool weather, fyi.

yes the cold air intakes work better under cool weather... but in warm-hot weather they absolutely suck. Perhaps I will buy an EVO intake kit for the "cold" season up here and switch back to the stock airbox when it gets warm....the factory airbox is more consistent in terms of performance...

these are my results FWIW. 281 RWHP ~338.5 FWHP 17% drivetrain loss. so do you think my mods have gained any HP?

Performance is always better in colder temps regardless of what intake you have installed. If you compare the performance of the EVO or stock or any other intake, it will ALWAYS provide better power in cold compared to hot climates. The performance difference as far as temp goes has nothing to do with the intake.

Read this to understand why a performance increase on a chassis dyno may actually represent a loss of performance in real world driving: http://dinancars.com/whitepapersFile.asp?ID=9 Written by Dinan for BMW's, but the same principles apply to Porsche.

Dyno charts are worthless. I can post my 623 RWHP chart for my 3.4 liter engine if you would like. Or, if you want, I can show more power. I love seeing a dyno run with the engine lid open and a fan blowing on it. Just like real life? I always drive with my trunk open towing a high powered fan behind me. How the car peforms is the only measurement that has any meaning. I can't begin to tell you how many cars that show a dyno of 600 hp or more that my little old 3.4 engine out performs. I have found that the more someone touts their dyno number, the lower the performance of his/her car. If you got it, prove it at the track or on the street.

I think Karlooz was just trying to show what the naysayers always ask for... numbers... looks like the run was also done with the lid closed. In the end, it still seems that the majority of us with mods are happy with the results in ALL driving conditions... yet the ones without the mods seem to know best and continously try to tell people that they are wasting their money and putting reliability at risk... This also seems to be the case with the SC vs. NA or Turbo debate... Those without the SC seem to know all the answers... I don't mean to totally downplay the opinions of those without mods... there is a lot of knowledge and experience to consider... just consider the source before you make any decisions with your checkbook...

This is funny, they have just proven that accelerometers are probably more accurate than a Dyno machine.. Everyone just get a $200 lighter plug in accelorometer from Passport/Bel etc.. .

Last night my buddy took me for a ride in his Turbo Charged Infiniti g35 coupe. We ended up next to a BPU'd WRX that runs 13.2 in the 1/4 mile and puts down 289hp(dynojet) to the wheels on a dyno. After months of tuning, my buddy's G35 puts down 360hp/400tq @6lbs of boost(via mustang dyno). My buddy beat the WRX easily even though he shifted gears at 5k rpms. There was no contest. HP, proven scientifically and on the dirty streets. I have hosted several Dyno Events in my past car club life and have seen the same cars with higher dyno numbers out perform cars with lower dyno numbers at 1/4 mile tracks. I've seen cars with intakes only out perform those without the intake some with a difference of .2 down the 1/4. .1 and .2 is a huge difference in the 1/4 world, it's almost 3 car lengths. I find it odd that a forum would find that all means of testing bolt on mods or any other type of mods are useless and ancedotal.

HUH? Are you trying to prove me right or wrong?

I beg to differ, the factory stock airbox will perform better than the EVO cold air intake/CONE filter on a very hot day... it's more consistent and doesn't bog down the engine on a warm/hot day like the EVO or ANY open cone filter element.

The EVO V Flow gets it's air from the same source as the stock unit does, so there would be absolutly no difference in intake temperature. I never even compared the stock intake to any other intake anyway. I simply stated that all intakes will benefit from colder air temps.

Yes and no... the cone has an opening which pulls in more air... more HOT air and if it's a hot/warm day it just pulls in more (I believe 36% more) hot air and bogs down the engine.... and becasue of it's increased breathing capacity it works better on a cool day... say less than 70F. The factory box is a much more consistent performer. On a hot day a car with the factory box will pull harder.

As far as I know, the V-flow only gets it's air from the OEM air scoop. The opening of the frame is sealed tightly against the deck whick closes out all engine heated air. Therefore, there is no difference in heat levels compared to the stock intake.

You are correct. You two are talking about two different types of conical intakes. The V flow is a Cold Air Intake as far as 996's go and the other intake is what we used to call HAI, hot air intakes, because it does suck in hotter air on very hot days because the intake isn't shielded from engine heat. QUOTE=1999Porsche911]As far as I know, the V-flow only gets it's air from the OEM air scoop. The opening of the frame is sealed tightly against the deck whick closes out all engine heated air. Therefore, there is no difference in heat levels compared to the stock intake.[/QUOTE]

I think the term "cold air intake" is misleading... the VFLOW certainly takes in more air and the effect is noticeable on a cool day... it is also noticeable in a -ve way on a very hot day... and the stock airbox doesn't suffer from this; that I have experienced personally.

Well, unless you are able to rewrite the laws a physics, I have no idea how the stock air box performs better than a box that functions exactly the same, only bigger. The size of the filter, in this case, since it's a closed system except for outside air, has no effect of intake temperature. What you night be feeling is that the stock airbox does not give the stepup in power in cold temps as much as the V-Flow does in the same temperatures. This would explain why you see less of a loss in power as the temperture gets warmer. Fact is" IF the V-flow allows more air to get to the engine AND computer managment can increase the fuel volume accordingly, the V-flow will always produce more power than will the stock intake.

I undestand what your saying but that was not our experience with the V-Flow on hot/days... the stock airbox ran much better... but when the weather cools off... lookout V-Flow rocks...

Chip and mods work well, many of these guys will tell you different but then they've probably never tried....... Best of luck!