Streetable 700whp 997.1TT, stock motor, 91 oct & 7000+ ft DA - doable or pipe dream?
#16
02-09-2019, 08:08 AM
Standard VTG. I asked in another thread without any answer: Does the 991GT2RS VTG bolt on 997.1? Any advantages over 997GT2?
I like to keep the vtg to avoid using boost controllers, external wg's... but spending 5k for less than 50hp is crazy. 991GT2RS has 700hp from factory so i would expect a increase of +100hp and that is more easy to swallow the cost ;p
I like to keep the vtg to avoid using boost controllers, external wg's... but spending 5k for less than 50hp is crazy. 991GT2RS has 700hp from factory so i would expect a increase of +100hp and that is more easy to swallow the cost ;p
#18
02-09-2019, 03:32 PM
This is my car specs: Cobb+TCU by ESMOTOR, Kline catless 70mm, HPTurbo VTG's 66mm, Forge DV's (yellow), DO88 Big Pack with IPD 82mm Y-Pipe oversized/dimpled, 82mm Throttle Body, IPD Plenum 82mm, complete 80mm intake piping from oem airbox to VTG, BMC airfilter.
Emre said that if i decided to add meth then ~750hp is possible. Even stock VTG is amazing on meth.
Thread below has gold information:
997 PDK Esmotor
Although is a 997.2 PDK, the power numbers increase on the 3.8 is similar to our 3.6. Performance not so much because of PDK advantage.
Emre said that if i decided to add meth then ~750hp is possible. Even stock VTG is amazing on meth.
Thread below has gold information:
997 PDK Esmotor
Although is a 997.2 PDK, the power numbers increase on the 3.8 is similar to our 3.6. Performance not so much because of PDK advantage.
#19
02-09-2019, 03:35 PM
Standard VTG. I asked in another thread without any answer: Does the 991GT2RS VTG bolt on 997.1? Any advantages over 997GT2?
I like to keep the vtg to avoid using boost controllers, external wg's... but spending 5k for less than 50hp is crazy. 991GT2RS has 700hp from factory so i would expect a increase of +100hp and that is more easy to swallow the cost ;p
I like to keep the vtg to avoid using boost controllers, external wg's... but spending 5k for less than 50hp is crazy. 991GT2RS has 700hp from factory so i would expect a increase of +100hp and that is more easy to swallow the cost ;p
But... I hear the price is so crazy that going with a Garret setup is way cheaper.
#20
02-12-2019, 07:38 AM
Basic Sponsor
__________________
#TeamAIM
997TT SilverSpool - 210.8 mph 1/2 Mile WR Apr 2019, 9.2 @ 168 mph 1/4 Mile Manual World Record , 3.15 60-130 mph , 2.72 100-150 mph , 1400whp E85
996TT SpoolBus - 204.6 mph 1/2 Mile 996TT WR Aug 2018, 9.5 @ 154 mph, 3.23 60-130 mph, 2.5 100-150 mph Manual Porsche World Record, 1400whp E85
997TT SlowBerry - 205.0 mph 1/2 Mile WR Nov 2018, 9.7 @ 170 mph 1/4 Mile , 3.2 60-130 mph , 2.4 100-150 mph , 1420whp E85
ESMOTOR | DO88 | TPC DSC | SYVECS | COBB | IPD | KLINE | XONA | AMS | ID | ERP | SACHS | TURBOSMART | CSF | DODSON |
#TeamAIM
997TT SilverSpool - 210.8 mph 1/2 Mile WR Apr 2019, 9.2 @ 168 mph 1/4 Mile Manual World Record , 3.15 60-130 mph , 2.72 100-150 mph , 1400whp E85
996TT SpoolBus - 204.6 mph 1/2 Mile 996TT WR Aug 2018, 9.5 @ 154 mph, 3.23 60-130 mph, 2.5 100-150 mph Manual Porsche World Record, 1400whp E85
997TT SlowBerry - 205.0 mph 1/2 Mile WR Nov 2018, 9.7 @ 170 mph 1/4 Mile , 3.2 60-130 mph , 2.4 100-150 mph , 1420whp E85
ESMOTOR | DO88 | TPC DSC | SYVECS | COBB | IPD | KLINE | XONA | AMS | ID | ERP | SACHS | TURBOSMART | CSF | DODSON |
#21
02-12-2019, 11:02 AM
Turbo cyl 4-6
Turbo cyl 1-3
But how much is a complete wg turbo kit for 750hp (headers, turbos, exhaust piping, oil/water piping, wastegates, boost controller...)? Under 15k?
Last edited by Tiago; 02-12-2019 at 11:06 AM.
#22
02-12-2019, 01:56 PM
Basic Sponsor
Turbo cyl 4-6
Turbo cyl 1-3
But how much is a complete wg turbo kit for 750hp (headers, turbos, exhaust piping, oil/water piping, wastegates, boost controller...)? Under 15k?
__________________
#TeamAIM
997TT SilverSpool - 210.8 mph 1/2 Mile WR Apr 2019, 9.2 @ 168 mph 1/4 Mile Manual World Record , 3.15 60-130 mph , 2.72 100-150 mph , 1400whp E85
996TT SpoolBus - 204.6 mph 1/2 Mile 996TT WR Aug 2018, 9.5 @ 154 mph, 3.23 60-130 mph, 2.5 100-150 mph Manual Porsche World Record, 1400whp E85
997TT SlowBerry - 205.0 mph 1/2 Mile WR Nov 2018, 9.7 @ 170 mph 1/4 Mile , 3.2 60-130 mph , 2.4 100-150 mph , 1420whp E85
ESMOTOR | DO88 | TPC DSC | SYVECS | COBB | IPD | KLINE | XONA | AMS | ID | ERP | SACHS | TURBOSMART | CSF | DODSON |
#TeamAIM
997TT SilverSpool - 210.8 mph 1/2 Mile WR Apr 2019, 9.2 @ 168 mph 1/4 Mile Manual World Record , 3.15 60-130 mph , 2.72 100-150 mph , 1400whp E85
996TT SpoolBus - 204.6 mph 1/2 Mile 996TT WR Aug 2018, 9.5 @ 154 mph, 3.23 60-130 mph, 2.5 100-150 mph Manual Porsche World Record, 1400whp E85
997TT SlowBerry - 205.0 mph 1/2 Mile WR Nov 2018, 9.7 @ 170 mph 1/4 Mile , 3.2 60-130 mph , 2.4 100-150 mph , 1420whp E85
ESMOTOR | DO88 | TPC DSC | SYVECS | COBB | IPD | KLINE | XONA | AMS | ID | ERP | SACHS | TURBOSMART | CSF | DODSON |
#23
02-18-2019, 11:48 PM
As others have said, skip the 997.2 intercoolers. The main thing is not to do things twice. So don't buy anything that doesn't meet your phase II requirements. If that means you just have a wait while you set the cash aside it's worth it vs. redoing things.
Call Robert at Forced Performance (He is half owner of Xona) and tell him what you're trying to do. He'll get you the right turbo out of the FP/Xona/Tial catalog.
Call Robert at Forced Performance (He is half owner of Xona) and tell him what you're trying to do. He'll get you the right turbo out of the FP/Xona/Tial catalog.
#26
02-26-2019, 04:28 PM
Join Date: Jan 2019
Location: Johannesburg
Age: 41
Posts: 37
Rep Power: 8 
Thank you to everyone that's weighed in - and apologies for my absence. It's been a helluva month.
I'll let this serve as an introduction for the car as well - 09 Gen 1.5 Manual Cabrio in Basalt Black - picked it up a couple of days before posting the thread. Pardon the iPhone pics.
The exhaust is on... 3" catless X-pipe system with dual resonators per bank. No drone whatsoever, but pretty loud - I love it.
As mentioned below, I'd have to do a lot of turbo homework on the intended Phase 2 setup, as I fear 3076's may drop out of boost between gear shifts, making it a schlepp to extract the best performance out of....
In fact, I might end up not going that route at all - I realize now that I should have bought a 997.2 PDK if I wanted to take on 600+ whp GT-R's without getting into the expense & commitment of a built engine. So instead of chasing the dragon for horsepower, I'll do bolt on mods that are cost effective & easily reversible, enjoy the car for a good while, and then when the time is right, weigh up the costs of an engine build & going for 900+ whp, versus the cost of getting into a 997.2 TT S and modding that to 650 whp.
Speaking of which, those sets of 63.5mm Protomotive upgraded VTG's in the classifieds section have caught my eye...
So, that probably means that for now, I could get away with:
Exhaust (Done)
Accessport
Air Filter
997.2 Intercoolers (do88's if I can swing a deal)
63.5mm VTG's
do88 Turbo inlet pipes
Custom tune
And then do these in one go when dropping the motor for the clutch job:
Sachs 2.5 Clutch
Y-Pipe, Plenum + 82mm TB kit
Aquamist Water/Meth Injection
Injectors
Pinned pipes (if necessary)
Am I once again barking up the wrong tree with the 997.2's? Or will they do the trick in this application?
EDIT: Nope, seems 997.2 IC's are still going to max out their cooling capacity relatively early on in this application, so I might as well do it properly.
A buddy of mine is flying out to the US this weekend, and has offered to mule back parts for me - so it looks like I might wind up going with AMS 5.5" coolers... costly, but reversible thanks to the included top shrouds -- which would cost me $1k to replace the stock ones locally if I had to hack them up for a different aftermarket cooler setup - so there's that at least... and the Y-pipe as well..
Thanks in advance for reading and any advice!
Good to know, thanks... I've been chatting to a chap at do88, but it doesn't seem like they intend to repeat that special anytime soon. At the $860 landed I'd pay for 997.2 IC's, they're looking appealing right now, if only as a stop-gap, or perhaps in the long run... we'll see.
Spinning the turbo's harder means more heat - an unhappy side effect of turbo tuning at altitude.
Good point... I've had a good sit-down after doing the exhaust, and realized that 3076's may not be what I'm looking for at altitude... I need to drive a 996 or 997.1 with them fitted to definitively make up my mind, but I fear that they might drop out of boost inbetween shifts and make for a very challenging car to drive quickly.
Thanks for that - helpful!
Good to know - I was thinking that a map custom-tuned to take advantage of the additional octane on meth injection might be enough to crack a safe 520-ish whp (with failsafe mode on the Aquamist unit to cut boost and save my *** if something goes wrong)
Thanks! Duly noted
Good advice, thanks. Will get hold of Robert and pick his brain regarding sizing if it does come to that.
I'll let this serve as an introduction for the car as well - 09 Gen 1.5 Manual Cabrio in Basalt Black - picked it up a couple of days before posting the thread. Pardon the iPhone pics.
The exhaust is on... 3" catless X-pipe system with dual resonators per bank. No drone whatsoever, but pretty loud - I love it.
As mentioned below, I'd have to do a lot of turbo homework on the intended Phase 2 setup, as I fear 3076's may drop out of boost between gear shifts, making it a schlepp to extract the best performance out of....
In fact, I might end up not going that route at all - I realize now that I should have bought a 997.2 PDK if I wanted to take on 600+ whp GT-R's without getting into the expense & commitment of a built engine. So instead of chasing the dragon for horsepower, I'll do bolt on mods that are cost effective & easily reversible, enjoy the car for a good while, and then when the time is right, weigh up the costs of an engine build & going for 900+ whp, versus the cost of getting into a 997.2 TT S and modding that to 650 whp.
Speaking of which, those sets of 63.5mm Protomotive upgraded VTG's in the classifieds section have caught my eye...
So, that probably means that for now, I could get away with:
Exhaust (Done)
Accessport
Air Filter
997.2 Intercoolers (do88's if I can swing a deal)
63.5mm VTG's
do88 Turbo inlet pipes
Custom tune
And then do these in one go when dropping the motor for the clutch job:
Sachs 2.5 Clutch
Y-Pipe, Plenum + 82mm TB kit
Aquamist Water/Meth Injection
Injectors
Pinned pipes (if necessary)
Am I once again barking up the wrong tree with the 997.2's? Or will they do the trick in this application?
EDIT: Nope, seems 997.2 IC's are still going to max out their cooling capacity relatively early on in this application, so I might as well do it properly.
A buddy of mine is flying out to the US this weekend, and has offered to mule back parts for me - so it looks like I might wind up going with AMS 5.5" coolers... costly, but reversible thanks to the included top shrouds -- which would cost me $1k to replace the stock ones locally if I had to hack them up for a different aftermarket cooler setup - so there's that at least... and the Y-pipe as well..
Thanks in advance for reading and any advice!
I have a pretty hot stock turbo setup, and while the 997.2 ICs were fine for a two-gear pull, IATs would destabilize after that and start heading for the sky. The Do88 big pack fixed that. Temps hardly rise above ambient on multi-gear runs (unless you're doing something like a half mile race). Do88 occasionally has 20% off sales, and that's when I grabbed mine. I would strongly recommend going with at least those based on your goals. No point in doing the intercoolers twice. Also while not hard, the IC install on these cars is annoying. Do it once 
The intercoolers would probably be fairly close. Markski uses Bell cores, they are a quality piece and for that amount of money I would jump on them. The SRM coolers are good value for the price new. I run the 997.2 coolers on a modest 1.2 bar setup in my 996tt. They are good for a road course type of setup but not as good for drag or highway racing. 997.2s are limited to modest boost levels or the end tanks blow off. The altitude should not hold you back too much, just spin the turbos higher. At your 700hp level you will likely need to upgrade your fuel pumps. Also at that level you are running some risk of pushing a head gasket. I pushed mine at the top of 5th gear at 1.3 bar. The high power stock engine build can be done, but if you aren't really committed I would just stay at that 600hp mark. I run my car around there and am very happy with it. It's best to choose a tuner that you like and go with one of the setups he has a lot of experience with. Good luck.
997.1tt stock fuel pumps will flow 1000whp worth of gasoline, also 997's have less xompression and better head gaskets than the 996tt 1.3bar is not much for this motor.
The GTX3076 is a beast but I won't use it on a stock car unless you build it in the future. Too much lag (even more for you) and you leave too much unused potential. Xona 61's have a bit better response, still overkill for a stock engine imo. Well, unless you are Brazilian then you just send it.
Best turbo for a stocker is the A28, 68 or 71 both little beasts, destroyers of many engines so make sure to tune on a dyno to keep tourque low and power high ...
Good luck ...
The GTX3076 is a beast but I won't use it on a stock car unless you build it in the future. Too much lag (even more for you) and you leave too much unused potential. Xona 61's have a bit better response, still overkill for a stock engine imo. Well, unless you are Brazilian then you just send it.
Best turbo for a stocker is the A28, 68 or 71 both little beasts, destroyers of many engines so make sure to tune on a dyno to keep tourque low and power high ...
Good luck ...
This is my car specs: Cobb+TCU by ESMOTOR, Kline catless 70mm, HPTurbo VTG's 66mm, Forge DV's (yellow), DO88 Big Pack with IPD 82mm Y-Pipe oversized/dimpled, 82mm Throttle Body, IPD Plenum 82mm, complete 80mm intake piping from oem airbox to VTG, BMC airfilter.
Emre said that if i decided to add meth then ~750hp is possible. Even stock VTG is amazing on meth.
Thread below has gold information:
997 PDK Esmotor
Although is a 997.2 PDK, the power numbers increase on the 3.8 is similar to our 3.6. Performance not so much because of PDK advantage.
Emre said that if i decided to add meth then ~750hp is possible. Even stock VTG is amazing on meth.
Thread below has gold information:
997 PDK Esmotor
Although is a 997.2 PDK, the power numbers increase on the 3.8 is similar to our 3.6. Performance not so much because of PDK advantage.
Phase 2 is very open ended, but Phase 1 will not get you 520whp. I ran virtually the same spec, and made around 580bhp at the fly, 480 at the wheels, so a 100bhp increase from stock (487 fly/402wheels). The car did 0-300 in around 30, 100-200 6.4. The stock turbos cannot flow anymore. GT2 based VTG's are the next upgrade but are very costly, so going to a wastegated turbo setup can make sense from that perspective.
Rick
Rick
I am sure with pure meth and just the right conditions you could drop to sub 6 but it isn't going to be easily repeatable. I did that in 4th only, 3rd - 4th was the same but it was a slow shift at the time. I think with your altitude you are going to struggle to reach a genuine 520WHP but the mods you suggest are spot on.
Rick
Rick
As others have said, skip the 997.2 intercoolers. The main thing is not to do things twice. So don't buy anything that doesn't meet your phase II requirements. If that means you just have a wait while you set the cash aside it's worth it vs. redoing things.
Call Robert at Forced Performance (He is half owner of Xona) and tell him what you're trying to do. He'll get you the right turbo out of the FP/Xona/Tial catalog.
Call Robert at Forced Performance (He is half owner of Xona) and tell him what you're trying to do. He'll get you the right turbo out of the FP/Xona/Tial catalog.
Last edited by BillyBawb; 02-27-2019 at 01:48 AM.
#27
03-08-2019, 08:15 AM
Join Date: Jan 2019
Location: Johannesburg
Age: 41
Posts: 37
Rep Power: 8
Right.... slippery slope, engaged.
I've purchased the Cobb AP V3 from @turboslut with the half-off custom tune offer from @SamboTT@ByDesign - many thanks to both of you gents. My buddy in Nashville has received the package, and will be bringing it back to SA for me next weekend.
I was sorely tempted to pull the trigger on the AMS Alpha intercooler kit at the same time, but ultimately I couldn't expect my buddy to lug something that bulky around in his suitcases.
Shipping from Europe is cheaper than the US, and the friendly folks at do88 cut me a hell of a deal on a bundle of goodies, so I've procured the following:
997.1 Big Pack - Coolers + Y-Pipe
Turbo Inlet Pipes
Cast Plenum for 82mm GT3 Throttle Body
Now I'll need to figure out turbo and injector upgrades... Still leaning towards a set of the used 63.5mm Proto's in the for sale section.... but if Sam could have his way, I'd probably wind up with XR 980's and a massive hole in my bank balance.
Oh, and while we're at it... a Sachs 2.5 clutch kit probably wouldn't hurt either.
I've purchased the Cobb AP V3 from @turboslut with the half-off custom tune offer from @SamboTT@ByDesign - many thanks to both of you gents. My buddy in Nashville has received the package, and will be bringing it back to SA for me next weekend.
I was sorely tempted to pull the trigger on the AMS Alpha intercooler kit at the same time, but ultimately I couldn't expect my buddy to lug something that bulky around in his suitcases.
Shipping from Europe is cheaper than the US, and the friendly folks at do88 cut me a hell of a deal on a bundle of goodies, so I've procured the following:
997.1 Big Pack - Coolers + Y-Pipe
Turbo Inlet Pipes
Cast Plenum for 82mm GT3 Throttle Body
Now I'll need to figure out turbo and injector upgrades... Still leaning towards a set of the used 63.5mm Proto's in the for sale section.... but if Sam could have his way, I'd probably wind up with XR 980's and a massive hole in my bank balance.
Oh, and while we're at it... a Sachs 2.5 clutch kit probably wouldn't hurt either.
#28
03-08-2019, 09:31 AM
First of all i'm no engineer. I had a healty discussion with DO88 about their Y-Pipe some time ago. My car has the IPD oversize y-pipe (61mm diameter and 82mm outlet), GT3 82mm throttle body size and IPD competition intake plenum 82mm . Stock y-pipe is 54mm with 74mm outlet. DO88 y-pipe is 70mm with 74mm outlet.
They was trying to make me belief that their y-pipe was better than my IPD and to buy the complete big pack. This made me think that despite the y-pipe diameter from each 2 pipes, the flow will go out by just one exit to throttle body. So atleast, you would want that the area of each pipe to be half of the area of throttle body connection.
DO88 y-pipe is made for stock throttle body 74mm. If you want the 82mm throttle body they will supply a silicone reducer from 82mm-74mm to connect throttle body to their y-pipe.
So i went back to times of school, grab a paper and calculator and start calculating circle areas. Got this numbers:
Stock Y-Pipe IN vs OUT +6.10% in
(2x54mm pipes vs 74mm)
DO88 Y-Pipe IN vs OUT +44.12% in
(2×70mm pipes vs 74mm)
IPD Oversize Y-Pipe IN vs OUT +9.65% in
(2x61mm pipes vs 82mm)
And 82mm outlet has +18.56% more area than 74mm.
My conclusion was that DO88 y-pipe will always bottle neck at oulet 74mm, despite even going larger after to 82mm TB. So i bought their DO88 big pack with connections to stock y-pipe size and kept IPD system with true 82mm diameter between y-pipe and intake plenum.
Sorry if my feedback is wrong but that made me sense at that time.
They was trying to make me belief that their y-pipe was better than my IPD and to buy the complete big pack. This made me think that despite the y-pipe diameter from each 2 pipes, the flow will go out by just one exit to throttle body. So atleast, you would want that the area of each pipe to be half of the area of throttle body connection.
DO88 y-pipe is made for stock throttle body 74mm. If you want the 82mm throttle body they will supply a silicone reducer from 82mm-74mm to connect throttle body to their y-pipe.
So i went back to times of school, grab a paper and calculator and start calculating circle areas. Got this numbers:
Stock Y-Pipe IN vs OUT +6.10% in
(2x54mm pipes vs 74mm)
DO88 Y-Pipe IN vs OUT +44.12% in
(2×70mm pipes vs 74mm)
IPD Oversize Y-Pipe IN vs OUT +9.65% in
(2x61mm pipes vs 82mm)
And 82mm outlet has +18.56% more area than 74mm.
My conclusion was that DO88 y-pipe will always bottle neck at oulet 74mm, despite even going larger after to 82mm TB. So i bought their DO88 big pack with connections to stock y-pipe size and kept IPD system with true 82mm diameter between y-pipe and intake plenum.
Sorry if my feedback is wrong but that made me sense at that time.
Last edited by Tiago; 03-08-2019 at 10:32 AM.
#29
03-14-2019, 08:12 AM
Join Date: Jan 2019
Location: Johannesburg
Age: 41
Posts: 37
Rep Power: 8
Update time... so, after finding out that the engine needs to be dropped in order to remove the stock turbo inlet pipes (and would have to be lowered anyways even just to hack them out ), I re-evaluated my options...
I did say from the start that I only intended on dropping the engine once... so cue Sam doing a deal for me on a Sachs 2.5 clutch kit and ID1300 injectors.
Be still, my aching credit card.
Now I just need to get the 82mm throttle body and a GT2 Slave kit, but those are cheap enough locally.
Interesting, thanks for your input.... Are you positive you're comparing the DO88 unit here? I'm a bit skeptical about that info, as the outlet looks significantly bigger than that in their pictures.
Have a look here:
If the two merging pipes are 70mm, then there's no way that outlet flange is 74mm, unless there's some serious perspective distortion at play...
But even in the event that it is in fact 74mm, I understand your viewpoint, and if one were to go for a really high horsepower application, I suppose the 74mm outlet could be a limiting factor.
However, seeing as the majority of the gain in fitting a Y-pipe comes from a lower pressure drop and an improved merge collector, I reckon the real world net difference between the IPD and do88 items would probably be academic at best.
However, if I'm wrong, and my setup underperforms, then I'll know where to go looking for a power upgrade.
Edit to add: I mailed Isak at @do88 earlier to enquire, and I just saw his response:
So it would seem that the do88 outlet is in fact larger in diameter than the IPD... I'll measure it myself once it arrives next week (with a bit of luck) and advise.
), I re-evaluated my options...I did say from the start that I only intended on dropping the engine once... so cue Sam doing a deal for me on a Sachs 2.5 clutch kit and ID1300 injectors.
Be still, my aching credit card.
Now I just need to get the 82mm throttle body and a GT2 Slave kit, but those are cheap enough locally.
First of all i'm no engineer. I had a healty discussion with DO88 about their Y-Pipe some time ago. My car has the IPD oversize y-pipe (61mm diameter and 82mm outlet), GT3 82mm throttle body size and IPD competition intake plenum 82mm . Stock y-pipe is 54mm with 74mm outlet. DO88 y-pipe is 70mm with 74mm outlet.
They was trying to make me belief that their y-pipe was better than my IPD and to buy the complete big pack. This made me think that despite the y-pipe diameter from each 2 pipes, the flow will go out by just one exit to throttle body. So atleast, you would want that the area of each pipe to be half of the area of throttle body connection.
DO88 y-pipe is made for stock throttle body 74mm. If you want the 82mm throttle body they will supply a silicone reducer from 82mm-74mm to connect throttle body to their y-pipe.
So i went back to times of school, grab a paper and calculator and start calculating circle areas. Got this numbers:
Stock Y-Pipe IN vs OUT +6.10% in
(2x54mm pipes vs 74mm)
DO88 Y-Pipe IN vs OUT +44.12% in
(2×70mm pipes vs 74mm)
IPD Oversize Y-Pipe IN vs OUT +9.65% in
(2x61mm pipes vs 82mm)
And 82mm outlet has +18.56% more area than 74mm.
My conclusion was that DO88 y-pipe will always bottle neck at oulet 74mm, despite even going larger after to 82mm TB. So i bought their DO88 big pack with connections to stock y-pipe size and kept IPD system with true 82mm diameter between y-pipe and intake plenum.
Sorry if my feedback is wrong but that made me sense at that time.
They was trying to make me belief that their y-pipe was better than my IPD and to buy the complete big pack. This made me think that despite the y-pipe diameter from each 2 pipes, the flow will go out by just one exit to throttle body. So atleast, you would want that the area of each pipe to be half of the area of throttle body connection.
DO88 y-pipe is made for stock throttle body 74mm. If you want the 82mm throttle body they will supply a silicone reducer from 82mm-74mm to connect throttle body to their y-pipe.
So i went back to times of school, grab a paper and calculator and start calculating circle areas. Got this numbers:
Stock Y-Pipe IN vs OUT +6.10% in
(2x54mm pipes vs 74mm)
DO88 Y-Pipe IN vs OUT +44.12% in
(2×70mm pipes vs 74mm)
IPD Oversize Y-Pipe IN vs OUT +9.65% in
(2x61mm pipes vs 82mm)
And 82mm outlet has +18.56% more area than 74mm.
My conclusion was that DO88 y-pipe will always bottle neck at oulet 74mm, despite even going larger after to 82mm TB. So i bought their DO88 big pack with connections to stock y-pipe size and kept IPD system with true 82mm diameter between y-pipe and intake plenum.
Sorry if my feedback is wrong but that made me sense at that time.
Interesting, thanks for your input.... Are you positive you're comparing the DO88 unit here? I'm a bit skeptical about that info, as the outlet looks significantly bigger than that in their pictures.
Have a look here:
If the two merging pipes are 70mm, then there's no way that outlet flange is 74mm, unless there's some serious perspective distortion at play...
But even in the event that it is in fact 74mm, I understand your viewpoint, and if one were to go for a really high horsepower application, I suppose the 74mm outlet could be a limiting factor.
However, seeing as the majority of the gain in fitting a Y-pipe comes from a lower pressure drop and an improved merge collector, I reckon the real world net difference between the IPD and do88 items would probably be academic at best.
However, if I'm wrong, and my setup underperforms, then I'll know where to go looking for a power upgrade.
Edit to add: I mailed Isak at @do88 earlier to enquire, and I just saw his response:
The inner bore facing the TB is 89 mm, and the connection diameter is 96 mm. We have never revised this item.
Last edited by BillyBawb; 03-14-2019 at 10:35 AM.
#30
03-19-2019, 05:15 PM
Join Date: Jan 2019
Location: Johannesburg
Age: 41
Posts: 37
Rep Power: 8 So my DO88 goodies arrived today, 5 days from shipping, delivered to my door (as opposed to having to fetch it from my local post office, like some imports), and also in spite of a minor clearing delay.
And it just so happens that I also got to meet up with my mate who muled the clutch, injectors and Cobb AP over from the US for me.
So with a bit of luck, we’ll be ready to install everything over the course of the next few days.
Oh, and I opened up the Y-pipe to check the outlet... it measured in at 88mm, so it’s unlikely to be a restriction point.
And it just so happens that I also got to meet up with my mate who muled the clutch, injectors and Cobb AP over from the US for me.
So with a bit of luck, we’ll be ready to install everything over the course of the next few days.
Oh, and I opened up the Y-pipe to check the outlet... it measured in at 88mm, so it’s unlikely to be a restriction point.