Sidewinder falling on its face

[brettallen517]

I’m having issues with my sled in longer pulls, it’s a 2018 sidewinder mtx, I’ve running Hurricane secondary intercooler, aluminum charge tubes, turbo smart blow off valve, Precision EFI 280 flash, stingray mods clutch kit with TP add ins, External intake, CR Racing straight pipe, TKI Belt drive. The sled runs great on shorter steep climbs but falls on its face on the longer pulls when climbing elevation. Holds 8900-9000 steady till it falls. Riding at 6400’ where it’s falling off. Just curious if anyone has had or seen this issue. It happens around 35 seconds in in this video and continues till I have to turn out. No cel lights or codes, I’ve always ran 100ll fuel.

https://youtu.be/JNaI1lb-yQo

 

[E-Zmoke]

I’m having issues with my sled in longer pulls, it’s a 2018 sidewinder mtx, I’ve running Hurricane secondary intercooler, aluminum charge tubes, turbo smart blow off valve, Precision EFI 280 flash, stingray mods clutch kit with TP add ins, External intake, CR Racing straight pipe, TKI Belt drive. The sled runs great on shorter steep climbs but falls on its face on the longer pulls when climbing elevation. Holds 8900-9000 steady till it falls. Riding at 6400’ where it’s falling off. Just curious if anyone has had or seen this issue. It happens around 35 seconds in in this video and continues till I have to turn out. No cel lights or codes, I’ve always ran 100ll fuel.

https://youtu.be/JNaI1lb-yQo

The stock turbo is only rated for 250HP your operating the turbo above its efficiency range at 280HP, the turbo is heat soaking and you are loosing power. The turbo needs to be upgraded to a larger turbo if you want to run above 250HP.

 

[MK4TDI]

Can you see what the intake temps are doing when it starts to fall off ? If they are to high I wouldnt be surprised if the computer is trying to save the engine.

And like e-zmoke said, anything after 250 on the stock turbo doesnt work in the hills. Might work in the flat lands with a pile of airflow going through the intercooler, but it still isnt being loaded as hard as climbing.

 

[brettallen517]

Intake temp hit a high of 115degrees, another king cat same setup but with hurricane 270 elevation tune blew out the top where I turned out. According to precision they don’t detune for intake temp. It’s been doing it side by side with other sidewinders and king cats, I’m the only one in the group running precision and the only one with the sled pulling back power. If I’m gonna go bigger turbo I’m throwing the mcx stage 3 on it with the 19t charger. I ordered a flash from hurricane their 270 high elevation tune, that’s all I’m swapping at the moment I’ll update this if it fixes my issue or if it still won’t perform on the longer pulls.

 

[RGM]

What's the fuel pressure when it cuts out. Might be the pump not being able to keep up.

 

[Lund]

Intake temp hit a high of 115degrees, another king cat same setup but with hurricane 270 elevation tune blew out the top where I turned out. According to precision they don’t detune for intake temp. It’s been doing it side by side with other sidewinders and king cats, I’m the only one in the group running precision and the only one with the sled pulling back power. If I’m gonna go bigger turbo I’m throwing the mcx stage 3 on it with the 19t charger. I ordered a flash from hurricane their 270 high elevation tune, that’s all I’m swapping at the moment I’ll update this if it fixes my issue or if it still won’t perform on the longer pulls.

There are NO TUNES that will make 250 and up HP. It is physically impossible to make that type of hp safely.
The injectors max flow and turbo small sizing limit the stock set up to no more then 250hp no matter what tune. All them tunes are BS advertisement. Anything more (above 250) the torque drops off drastically and the air fuel ratios are dangerously LEAN.(why hp goes up and torque falls off)
There is only one way to make bigger HP with the Winder, that is with major component changes, like bigger injectors and turbo as a start.
IMO MCX is the only good option.

 

[Lund]

I’m having issues with my sled in longer pulls, it’s a 2018 sidewinder mtx, I’ve running Hurricane secondary intercooler, aluminum charge tubes, turbo smart blow off valve, Precision EFI 280 flash, stingray mods clutch kit with TP add ins, External intake, CR Racing straight pipe, TKI Belt drive. The sled runs great on shorter steep climbs but falls on its face on the longer pulls when climbing elevation. Holds 8900-9000 steady till it falls. Riding at 6400’ where it’s falling off. Just curious if anyone has had or seen this issue. It happens around 35 seconds in in this video and continues till I have to turn out. No cel lights or codes, I’ve always ran 100ll fuel.

https://youtu.be/JNaI1lb-yQo

I have listened to your video and to me it sounds more like your sled is forgetting to back shift, staying shifted out and pulling the engine down.
On the biggest pull's last season mine was doing the same or similar. Insane track speed and nearing the top of a pull i could distinctively hear and see the RPMs slowly but surely drop off causing the slight lost in power.
It was the secondary not holding back enough. Changed out the cam, track speed went up even more and no more power lost.

 

[1200]

Wow it sounds terrible

 

[1200]

That hill must be crazy steep or that sled is not making power?

 

[brettallen517]

Thanks everyone for all the suggestions and things to check. Ended up being the precision 280 flash. Re flashed my sled with Hurricane and 270 high elevation tune, Wow what a difference, sled pulls harder off the bottom and never skipped a beat all the way out the top. Sled held 9050 rpm, 17psi boost and intake temp never went over 110. Still going to do the hi glow fuel pump and return line relocate for peace of mind

 

[Lund]

I know a guy that ran the 270 high elevation tune from Hurricane, my 225MCX would walk on him all day long in the deep no matter what he did.
He now runs the MCX 300+hp and cleans my arse.
What's your O2 reading at?

 

[1200]

Well sweet u got it working. I got the 250 mcx on mine its ok .

 

[Lund]

Well sweet u got it working. I got the 250 mcx on mine its ok .

The MCX 250 setup is very nice, another friend of mine has it on his Winder.
When i originally did the Winder build i ordered the MCX 250 and during the build i met a guy who was looking into getting a 250 from MCX but there was no stock, anywhere. So i sold him my kit at an extra cost and ordered a 225 set up instead, stock available.
There were a couple of deciding factors on this.
1- When i had my 260hp set up in my Nytro i found my self never using it, had it dialed to about 230-40, 99% of the time. Running only 12 and 14lbs boost yet i could go 18lbs by dialing my turbosmart boost controller.
I guess its called age and a change in some riding desires. Like riding steep and deep in the back country over big chute slays.
2- i sold it for $500.00 more then what i paid.
3- The overall cost of the 250MCX, plus dialing it in (PROPERLY) many are not and proof is when you put it up against another Winder. Was nearly $2000 more then the 225mcx.
That sealed it to satisfy my needs.

 

[1200]

Ya seems to run fine. Im going to put a 174 on for next season that should be a lot better

 

[Lund]

Ya seems to run fine. Im going to put a 174 on for next season that should be a lot better

Get the 9115M and cut it down, its the only track that will hook up and not fold over giving the Winder standup wheelie in 4ft of pow.
It will give your MCX250 some bite and not just sound cool.