GT4 - Unlocking the Power Potential!
02-17-2016, 03:59 PM
#331
Nordschleife Master
I guess one could say that 50% of the benefits are realized without tuning. If the motor is sucking more air then it will make more power. BUT, it's being told to target a certain Air Fuel Ratio and the motor will compensate once it sees additional air volume via the MAP sensor. You do get an added bit of HP IF the ECU does not find a way to back down the Air Fuel Ratio and can't physically "fatten up" the mixture. Most standard DFI Porsches from the factory run 12.7 on the Air Fuel Ratio at WOT when moving up and passed 6K RPM so if the added throttle body adds air and the ECU does nothing about it, it will in fact become leaner and approach 13.0 which is the magic HP spot on a Porsche from 6K RPM to redline. Going beyond this is going into aggressive territory just like adding a bunch of ignition timing would also be but that's an entirely different discussion.
I should've mentioned 15 to 1 is what the computer wants to see at idle of course. At WOT it goes into open loop anyway and the O2s are irrelevant(they are not switching within stoichiometric).
02-17-2016, 04:26 PM
#332
Pro
Join Date: Nov 2008
Location: Sierra Madre, Ca.
Posts: 569
Likes: 0
Received 0 Likes
on
0 Posts
I was told by a Southern California dealer that they sent one of their first GT4's to a Southern California tuner that has a good rep amongst the GT3 crowd for the 82mm TB conversion, and that no CEL resulted from the swap.
02-17-2016, 04:37 PM
#333
best not to assume those gains at all imo with no back up dyno.
with the tune and the parts you get 415BHP with the sports cat manifold.
with the Manifold only you get 5bhp gain at the top end.
Just no point fitting any single part imo, you do the kit or nothing imo.
02-17-2016, 04:46 PM
#334
Rennlist Member
I assume there is no flash done ?
TIA
Regards
Ed
02-17-2016, 04:51 PM
#335
Race Director
First shop to post tb/plenum gains without a tune and without cells is going to sell a lot of product. First owner to buy is going to get a lot of questions via pm.. My inbox jammed up when I posted about my header install. Looking forward to all this... If we figure out whether the Porsche ecu allows for this flexibility it will be a really important step for all of us who are concerned about the potential tune/warranty deletion issue. Then again.. First person to get reliable info that they installed a tune like the Cobb, removed it, and it was not visible to Porsche is going to be the real ground-breaker... But I doubt that can happen with today's OEM ecu logging.
02-17-2016, 05:07 PM
#336
Rennlist Member
doubt it.
best not to assume those gains at all imo with no back up dyno.
with the tune and the parts you get 415BHP with the sports cat manifold.
with the Manifold only you get 5bhp gain at the top end.
Just no point fitting any single part imo, you do the kit or nothing imo.
best not to assume those gains at all imo with no back up dyno.
with the tune and the parts you get 415BHP with the sports cat manifold.
with the Manifold only you get 5bhp gain at the top end.
Just no point fitting any single part imo, you do the kit or nothing imo.
02-17-2016, 06:05 PM
#337
Rennlist Member
Just so we are clear, I am not refuting what you are saying; yes, I agree with you 100% that the easiest way to make more power is to add more air to the giant air pump. I was just chiming in to defend the reason we suggest the tune with the intake mod. Outside of closing the throttle down via the ROM map, the single biggest way to mechanically restrict any car is to give it a smaller throttle body which is the same thing racing sanctioning bodies do when they give cars a "restrictor." If you make the hole smaller, it makes less power and less torque. Sure you can try and tune around some of it but the reality is that less air is less power. Furthermore, I am not assuming you don't already know any of the above, just adding color for the folks reading along.
Had i just stated that the car will make more power with a bigger throttle body and no flash then you probably would have seen the point I was trying to make.
Had i just stated that the car will make more power with a bigger throttle body and no flash then you probably would have seen the point I was trying to make.
. I appreciate all the info you provide us. If my car was a track car, I'd already have data to provide all the RL'ers....LOL. I might just install one anyway, or get one of the other 4 local guys to, they all track theirs. I'll put a bug in somebody's ear this week.....
In general, I think this is a great discussion, that gives people as many options as possible.
02-17-2016, 06:53 PM
#338
and does not know if the car will burn your pistons running to lean, or rich or what ever , if the parts are fitted with no tune.to assume a figure is not wise.
there is ONE guy who has all this Data, Jens Ehresmann, if you want to know what just fitting the parts will do with no tune , send him a mail.
(he is on Holiday atm though)
to edit, I sent him a message and the car will run too rich if you fit the parts with no tune ;-)
Last edited by mrd_spy; 02-17-2016 at 07:25 PM.
02-17-2016, 07:01 PM
#339
Basic Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Thread Starter
Yes, has he has no data and does not know if the car will burn your pistons running to lean if the parts are fitted with no tune. to assume a figure is not wise. there is ONE guy who has all this Data, Jens Ehresmann, if you want to know what just fitting the parts will do with no tune , send him a mail. (he is on Holiday atm though)
and does not know if the car will burn your pistons running to lean if the parts are fitted with no tune. to assume a figure is not wise. there is ONE guy who has all this Data, Jens Ehresmann, if you want to know what just fitting the parts will do with no tune , send him a mail. (he is on Holiday atm though)Last edited by BGB Motorsports; 02-17-2016 at 08:29 PM.
02-17-2016, 07:05 PM
#340
Nordschleife Master
Yes, has he has no data and does not know if the car will burn your pistons running to lean if the parts are fitted with no tune. to assume a figure is not wise. there is ONE guy who has all this Data, Jens Ehresmann, if you want to know what just fitting the parts will do with no tune , send him a mail. (he is on Holiday atm though)
and does not know if the car will burn your pistons running to lean if the parts are fitted with no tune. to assume a figure is not wise. there is ONE guy who has all this Data, Jens Ehresmann, if you want to know what just fitting the parts will do with no tune , send him a mail. (he is on Holiday atm though)He estimated a number and I'm sure that's conservative if you ask me. But he did it because many here,myself included are always asking for numbers.
I don't know about your guy,have never heard of him. If he would like to join Rennlist as a forum sponsor and present his work,we will be more than happy to have options,but let's not " talk down " someone else's thread.
02-17-2016, 07:17 PM
#341
John from BGB Motorsports is a very reputable presence on this board. He has been more than honest and open with his data. If I were a tuner,I wouldn't have discussed all my secrets wide open like he did. I am sure he will provide solid numbers once all the options have been tested.
He estimated a number and I'm sure that's conservative if you ask me. But he did it because many here,myself included are always asking for numbers.
I don't know about your guy,have never heard of him. If he would like to join Rennlist as a forum sponsor and present his work,we will be more than happy to have options,but let's not " talk down " someone else's thread.
He estimated a number and I'm sure that's conservative if you ask me. But he did it because many here,myself included are always asking for numbers.
I don't know about your guy,have never heard of him. If he would like to join Rennlist as a forum sponsor and present his work,we will be more than happy to have options,but let's not " talk down " someone else's thread.
All the current dyno's on this forum are from Jens workshop in Germany !!
02-17-2016, 07:19 PM
#342
You my friend, are quite the character.
1.) my numbers I quoted are directly from Jens in Germany; I didn't make them up, he told them to me and I can't for the life of me figure out why you never give credit to what I say but refer to his findings as gospel. Where do you think I got my dyno runs?
2.) i hate to break it to you but people have been installing Plenums on Porsches with no tune for over 8 years now.
If you wouldn't mind, search for another bridge to hang out under if you get a chance! If you need me, I will be making up data and hiding my records of piston and motor failures.
just to confirm, everyone is going to buy Plenums and throttle bodies from a shop who tries this and documents it, regardless of their knowledge of anything else?
1.) my numbers I quoted are directly from Jens in Germany; I didn't make them up, he told them to me and I can't for the life of me figure out why you never give credit to what I say but refer to his findings as gospel. Where do you think I got my dyno runs?
2.) i hate to break it to you but people have been installing Plenums on Porsches with no tune for over 8 years now.
If you wouldn't mind, search for another bridge to hang out under if you get a chance! If you need me, I will be making up data and hiding my records of piston and motor failures.
just to confirm, everyone is going to buy Plenums and throttle bodies from a shop who tries this and documents it, regardless of their knowledge of anything else?
Jens Ehresmann ...you could install everthing without a proper tune. But the engine runs far to rich. That's the reason why we sell our powerkits only with a 2nd ecu including related mapping.
02-17-2016, 07:23 PM
#343
Pro
Join Date: Nov 2008
Location: Sierra Madre, Ca.
Posts: 569
Likes: 0
Received 0 Likes
on
0 Posts
02-17-2016, 07:32 PM
#344
Nordschleife Master
Also,rest assured I do my homework very well and I think I have a pretty good understanding of how things work...
02-17-2016, 07:43 PM
#345
have a nice night ;-)