Jemboxster Posted August 10, 2017 Report Share Posted August 10, 2017 Hi everyone im new to this forum, I need some info on upgrading my gearbox in my 986 Boxster s. I have had the car nearly 5 years now. The 2nd gear sync had started to fail as usual. I wanted to know if I can put a carrera gearbox in it or Cayman box in order to get more power and torque from the car. Has anyone done this or know what it will take to do this upgrade and if the outcome will be positive. thanks Link to comment Share on other sites More sharing options...
pquadro Posted August 10, 2017 Report Share Posted August 10, 2017 As far as I know the reccomends upgrade is a 997 shifter / box. I'm planning to install the short shifter myself https://www.porscheshop.co.uk/porsche-performance-parts/porsche-boxster-986-performance-parts-1997-to-2004/porsche-boxster-986-gearbox-transmission-upgrades-1997-to-2004/short-shift-kit-996-986-oe.html Link to comment Share on other sites More sharing options...
Jemboxster Posted August 10, 2017 Author Report Share Posted August 10, 2017 Thanks for the reply. so just the shifter or shifter and gearbox from 997 Link to comment Share on other sites More sharing options...
edc Posted August 10, 2017 Report Share Posted August 10, 2017 A short shifter is not going to help an internal gearbox or syncro problem. A new box won't give you any more power or torque either. The only way you will get that effect is if you change the gearing or ratios so you get through the gears quicker. If the gearbox is knackered then a straight replacement is probably the cheapest bet. A rebuild will be into 4 figures. Link to comment Share on other sites More sharing options...
Menoporsche Posted August 11, 2017 Report Share Posted August 11, 2017 IIRC a 2.5 box could improve your acceleration. Link to comment Share on other sites More sharing options...
Jemboxster Posted August 11, 2017 Author Report Share Posted August 11, 2017 Thanks for the reply guys, i didn't want to just improve acceleration I was hoping for more power output throughout the gear range. Im actually wondering now if the 997 gearbox will fit and if it will give me the result I'm looking for as said by EDC it will be expensive to rebuild and modify but buying a faster gear box already from a faster Porsche seems better. Link to comment Share on other sites More sharing options...
Southy Posted August 11, 2017 Report Share Posted August 11, 2017 18 minutes ago, Menoporsche said: IIRC a 2.5 box could improve your acceleration. This forget the 997 gear box, porsche are masters at producing cars at certain power levels if you really want a faster porsche you need to buy a faster porsche. Link to comment Share on other sites More sharing options...
Yuggr Posted August 11, 2017 Report Share Posted August 11, 2017 As Southy states you are barking up the wrong tree. A gear box can only change the ratio of engine revolution to rear wheels revolution, taking into account the ratio of the diff. For more power and torque you need to mod or replace the engine. Link to comment Share on other sites More sharing options...
pquadro Posted August 11, 2017 Report Share Posted August 11, 2017 Sorry I misread. I guess if you are replacing the gearbox you might as well get a better shifter Link to comment Share on other sites More sharing options...
Jemboxster Posted August 11, 2017 Author Report Share Posted August 11, 2017 Ah I see. That's very helpful info thanks guys. I was trying to avoid modding the engine as I saw a guy on youtube do the throttle body exhaust mods and although they got more power top end there was a dip in torque at lower revs. i was hoping a change of gear box would give me steady increase throughout. I won't do an engine replacement although I know they work well in these cars as I love the original noise and top end is more than enough. just wanted a better pick up speed at lower revs Link to comment Share on other sites More sharing options...
edc Posted August 11, 2017 Report Share Posted August 11, 2017 In simple terms the gearbox doesn't make any power. As already mentioned it just turns engine power into turning round the rear driven wheels. If it was a bike the engine is the body and legs of the person on the seat. The gearbox is the gearset on the bike. Link to comment Share on other sites More sharing options...
edc Posted August 11, 2017 Report Share Posted August 11, 2017 If you are new to modding then starting with gearbox is not only a rare thing to do in it's own right but also a hard place to learn. If you want to accelerate faster with the same engine you have to change the gear ratios themselves or the diff ratio. I have been looking at this on and off for 5 years and there are very few options all of which cost a lot of money. Link to comment Share on other sites More sharing options...
Patt Posted August 11, 2017 Report Share Posted August 11, 2017 Read through the link "986S 2000" link in EDC's signature. We went through various modifications on that car. The throttle body one is great and on both his and my car there was no dip in performance anywhere. Generally 6bhp and 12lbft across the whole rev-range. Whilst that doesn't sound much, it is very noticeable to drive and response is much quicker. And the required changes to the intake pipe removes one of the strangulation points Porsche put in to keep the 911 owners happier. The re-map had more changes to where the power was enhanced, but it's not necessary as the standard ECU will adapt to most modifications. Shifter change is a more personal thing. I've gone from 986 > 986/987 short shift> 997/987 > 997 GT3 style (modified 997) in the search for the feel I wanted. If you want significant power and torque increases, either change the displacement/engine or buy Porsche with that as standard. If you want to go faster - get driver training to enjoy the car you have , and more importantly safely. Link to comment Share on other sites More sharing options...
Tex24v Posted August 11, 2017 Report Share Posted August 11, 2017 I replaced my gearbox last year, (not to improve performance) but because of the syncro problem you mention, I changed the gearbox oil first, as some thought this might help and is nice and cheap, but mine got worse and in the end second gear was blocking altogether. I was quoted £1650 for a rebuild. I bought a used 2003 gearbox (with about half the mileage of my car) from Douglas Valley for around £500 and then paid about the same to get it fitted, saving about £600. I think Douglas Valley say that they test the boxes, but don't claim that they have been rebuilt/reconditioned in any way. So I guess there is a risk that you might end up with a box with the same issue, I took that chance and have been lucky that it works perfectly. My advice would be to do what I did, change oil first, see if it improves, then decide at what point you can no longer live with it, or if the failure develops like mine, and then replace rather than recondition. Obviously if you have a low mileage minter, then you may want to keep 'matching numbers' as they say. I didn't/don't so it didn't bother me. Correct me if I'm wrong but wouldn't a 911 gearbox run in the wrong direction, maybe easier than I think to switch that though? Link to comment Share on other sites More sharing options...
Jemboxster Posted August 11, 2017 Author Report Share Posted August 11, 2017 Thanks so much for all this help guys all comments have been helpful to me I should of jumped on the forums sooner. I was going to do the throttle body upgrade as I have heard it wakes the Boxster up which is what I'm looking for it's only the video on youtube put me off thats the one I saw. This guy on road and race I find very helpful while owning my Boxster. I know the gearbox and diff upgrade are expensive but I'm not ever going to sell my Boxster so don't mind investing in them mods if they were to prove useful. I'd even invest in changing the gear ratios in my current box to get the power as said by Tex24v to keep the numbers the same. Plus pulling away from the more powerful porshes will be a look on their face worth seeing Ah feeling a bit confused by all this now lol I'm not what you would call a professional at this just a youtube DIYer. Link to comment Share on other sites More sharing options...
Southy Posted August 11, 2017 Report Share Posted August 11, 2017 1 hour ago, Jemboxster said: Ah I see. That's very helpful info thanks guys. I was trying to avoid modding the engine as I saw a guy on youtube do the throttle body exhaust mods and although they got more power top end there was a dip in torque at lower revs. i was hoping a change of gear box would give me steady increase throughout. I won't do an engine replacement although I know they work well in these cars as I love the original noise and top end is more than enough. just wanted a better pick up speed at lower revs I've just re-read my original post (Done by mobile!) I doesn't come across all that well. A few have fitted 2.5 gearbox and this does improves acceleration at the cost of a few MPH at top speed, I believe quite a bit of work is involved with this and it might not be what your looking for. Check out EDC's mods for his 986, you might some that you feel you'd like to try Personally I followed some of the mods and then did a few of my own, my car being a 2001 S - it's never going to fast in the sense of a modern car, so I've added to the experience of actually driving the car. My car has the following mods done: K&N air filter (Increased induction noise) De-snorkel (More induction noise) Ebay special stainless Steel Manifolds (Helps flow and adds to exhaust note) By-pass mod on the rear exhaust back box (Makes a big difference to the overall sound) all these changes were made firstly with the intention of the aural experience and any performance enhancements is a nice side effect. I have the 911 throttle body mod to do next and that will complete my personal mechanical mods. Link to comment Share on other sites More sharing options...
edc Posted August 11, 2017 Report Share Posted August 11, 2017 Most of the stuff you see on the Youtube video you linked too was all researched and taken from users like myself on here ... Link to comment Share on other sites More sharing options...
edc Posted August 11, 2017 Report Share Posted August 11, 2017 If a simple rebuild is 1,650 then custom gear ratios or even carefully selected ones off the shelf is going to come in at at least double that price. A new shorter diff / pinion is in the same ballpark price. Then whilst you are there you might as well consider fitting a ATB or LSD of sorts so then you can add another 400-1000 again. There's a reason why you will find very little information on gearbox based stuff. It's because very few outfits actually do this work, the cost is a lot and owners typically find better value elsewhere for their mods. If you are down this road then you will also be thinking about a new clutch, add another 600. Then before you even get here you should think about under drive pulley and lightweight flywheel. The premise is the same to get the engine revving faster, effectively quicker acceleration, but again there is no power gain as such. Link to comment Share on other sites More sharing options...
jonnoshore Posted August 11, 2017 Report Share Posted August 11, 2017 Fit a 3.8 engine on a 2.5 5 speed Gbx if faster is the aim... Link to comment Share on other sites More sharing options...
Menoporsche Posted August 11, 2017 Report Share Posted August 11, 2017 Also look at marseille's thread. Rather than boosting power, he removed weight, 80kg-ish. He then boosted power Link to comment Share on other sites More sharing options...
pquadro Posted August 12, 2017 Report Share Posted August 12, 2017 14 hours ago, Menoporsche said: Also look at marseille's thread. Rather than boosting power, he removed weight, 80kg-ish. He then boosted power That's quite a lot! Could you link? Link to comment Share on other sites More sharing options...
marseille Posted August 12, 2017 Report Share Posted August 12, 2017 On 11/08/2017 at 8:07 AM, Jemboxster said: Thanks for the reply guys, i didn't want to just improve acceleration I was hoping for more power output throughout the gear range. Im actually wondering now if the 997 gearbox will fit and if it will give me the result I'm looking for as said by EDC it will be expensive to rebuild and modify but buying a faster gear box already from a faster Porsche seems better. Fitting a 997 gearbox to a Boxster will certainly give you interesting results sir, that I'll be 6 reverse gears and forward one ? Link to comment Share on other sites More sharing options...
marseille Posted August 12, 2017 Report Share Posted August 12, 2017 21 hours ago, Menoporsche said: Also look at marseille's thread. Rather than boosting power, he removed weight, 80kg-ish. He then boosted power It's actually close to a 100kg then I turned up the power to 318 hp every time I floor it the poor old 2.5 5 speed shouts out is that the best you've got. Link to comment Share on other sites More sharing options...
Jemboxster Posted August 12, 2017 Author Report Share Posted August 12, 2017 318 hp from the 2.5!!? That's brilliant what did you do to it on the modding side of things apart from stripping it Link to comment Share on other sites More sharing options...
Nobbie Posted August 12, 2017 Report Share Posted August 12, 2017 36 minutes ago, Jemboxster said: 318 hp from the 2.5!!? That's brilliant what did you do to it on the modding side of things apart from stripping it He replaced it with a 3.4 996 engine, read the details of his ride under his avatar? Link to comment Share on other sites More sharing options...
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