DeMan Motorsport GT4 4.25L engine introduction
#62
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#63
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Just got a ride in a 4.25l Spyder and the torque is insane!!! Wow. Completely different from my 4lx51 which was completely different again from a stock 3.8, it's hard to believe these are all the same engine at all. Low and mid-range torque is massive, so meaty, and when you roll into the throttle around 2500rpm the engine delivers a swell of torque without even going wot. From 3k-5k rpm where my engine is just waking up the 4.25l is already fully on and pushing you back into the seat hard. It feels like a totally different engine because there's power everywhere, all the time, and the torque delivery is super smooth through the whole rev range.
For reference, my 4lx51 is all top end with an almost stock like feel below 3k rpm that ramps up dramatically in the mid range and really screams from 6k-8k rpm. It's exciting but you need to rev it past 5k rpm to get to into it's sweet spot which isn't often reasonable on the street. The 4.25l is a hammer, it gives you torque on demand. Corner exit, hooning, commuting, whatever, this engine has a vastly wider and stronger power band. The 4lx51 feels fast because the torque builds with rpms and it's all noise and fury at the top end which I love but the 4.25l just IS fast. My 4lx51 with the lighter clutch/flywheel combo and race headers still feels like a more aggressive set-up from a sound and throttle response perspective over the 4.25l but then when you bury the pedal the 4.25l deliver so much torque it's like scrappy poo barking at a bear. I stepped back into my 4lx51 for the drive home and at street friendly rpms it honestly felt slow by comparison which I was not expecting. I have almost 9k miles on my 4lX51 and haven't driven a stock GT4 in, well, 9k miles, so I can't imagine what this would be like for someone coming from a stock engine.
Stepping back from it all, it's hard to believe these are all the same engine. The feel of these different engine builds are so different it's clear to me that Porsche gave the GT4 the engine they wanted to fit in their product line, not the best engine they could have given us for the price. Porsche de-tuning has made these maybe the most mod-friendly NA engines I've seen short of a sbc. Torque, horsepower, 4L, 4.25l, X51, GT3 intake, whatever you want there is more in this engine if you want it....
For reference, my 4lx51 is all top end with an almost stock like feel below 3k rpm that ramps up dramatically in the mid range and really screams from 6k-8k rpm. It's exciting but you need to rev it past 5k rpm to get to into it's sweet spot which isn't often reasonable on the street. The 4.25l is a hammer, it gives you torque on demand. Corner exit, hooning, commuting, whatever, this engine has a vastly wider and stronger power band. The 4lx51 feels fast because the torque builds with rpms and it's all noise and fury at the top end which I love but the 4.25l just IS fast. My 4lx51 with the lighter clutch/flywheel combo and race headers still feels like a more aggressive set-up from a sound and throttle response perspective over the 4.25l but then when you bury the pedal the 4.25l deliver so much torque it's like scrappy poo barking at a bear. I stepped back into my 4lx51 for the drive home and at street friendly rpms it honestly felt slow by comparison which I was not expecting. I have almost 9k miles on my 4lX51 and haven't driven a stock GT4 in, well, 9k miles, so I can't imagine what this would be like for someone coming from a stock engine.
Stepping back from it all, it's hard to believe these are all the same engine. The feel of these different engine builds are so different it's clear to me that Porsche gave the GT4 the engine they wanted to fit in their product line, not the best engine they could have given us for the price. Porsche de-tuning has made these maybe the most mod-friendly NA engines I've seen short of a sbc. Torque, horsepower, 4L, 4.25l, X51, GT3 intake, whatever you want there is more in this engine if you want it....
#64
Was the engine on the Spyder the Street or race version? Sounds like maybe the street which offers more torque low on the rev range.
#66
Three Wheelin'
I did! And then I spent the last hour hitting every wall at Portimao in a full motion 270 degree driving simulator. I need to trade the GT4 in for a miata and a driving coach.....
#67
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You'd have a Monster Miata conversion 1/2 way through the summer.😂😂
#68
Custom designed long stroke Crankshafts, lightweight rods and Pistons along with CNC ported heads with either Titanium or steel valve train parts, are all available, up to 4.5L.
These parts are all custom and not re using stock Porsche GT3/GT4 parts.
#69
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4.5L GT4 engine is already a reality at DeMan Motorsport. Stay tuned for dyno results and road reviews shortly!
__________________
2016 GT4-R
Rick DeMan
DeMan Motorsport
Upper Nyack, NY
845 727 3070
Porsche Sales & Service
Porsche Race services and parts
www.DeManMotorsport.com
2016 GT4-R
Rick DeMan
DeMan Motorsport
Upper Nyack, NY
845 727 3070
Porsche Sales & Service
Porsche Race services and parts
www.DeManMotorsport.com
#70
I wonder how the 4.25L would perform with Dundon runners? Seems like that would be the perfect combo if the runners added similar topend power as they're advertised to do on the stock motor while retaining the low end grunt of the street version.
#71
#72
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DeMan Motorsport is using the actual GT3 RS complete intake system. So I would imagine some comparable results would be had with the Dundon runners.
#73
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I guess I and most others would like to see the quantitative and qualitative differences between stock, 4.25L, and 4.5L when that's possible to provide. We were talking yesterday of setting up a group visit of 5-10 people to Deman Motorsport in the near future. Rick, what would the chances be for that to occur?
#74