High intake temps when mountain riding!!

hpmaniac

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Location
Washington
Country
USA
Snowmobile
2025 mtx sidewinder
2024 9r turbo
2025 summit xpert 165 turbo r
My 300hp tune sidewinder runs like an animal on the trails with a clean front grill and intake temps less than 90f, But when playing in deep snow or hill climbing that grill gets clogged so easy and the intake temps sky rocket and power falls a bunch, On a moderate 10 second pull up a hill i can go from 70f to 125-130 intake temps and power falls off. Has anyone ever mounted a fan on the back side of the front intercooler?? i know hurricane makes the secondary cooler which would help a bunch but that is another 1k. Its not clutching, it will pull 9100 on trail, pull 8900 on the start of a climb and mid way it will pull down to 8200 and drop power a bunch. Running a 35 helix, dalton black orange so that should be plenty of backshift. I need to talk with Dave at hurricane and ask at what temps will the ecm start pulling power, timing and boost. I see 16.5 psi on a climb at 5k feet on the 300 header tune. I pressure tested system and it hold 20 psi. I have NOT checked crack pressure yet on waistagate. Wideband is showing 11.6 11.7. Tune is spot on. I can make it pull like a train on the trails. Straight 40 degree helix, 78 grams weight, 9k rpm and she is a rocket. I run the 35 helix for hill climbs.
 
Do you still have your air filter or stock air intake under the hood? The colder the air going into the turbo, the colder the air coming out of it. Also the stock turbo has it's tongue hanging out on a 300 header tune at 5,000 foot elevation. I actually think your power is probably closer to 8500 rpm with the header tune at 5,000 foot elevation.
 
Do you still have your air filter or stock air intake under the hood? The colder the air going into the turbo, the colder the air coming out of it. Also the stock turbo has it's tongue hanging out on a 300 header tune at 5,000 foot elevation. I actually think your power is probably closer to 8500 rpm with the header tune at 5,000 foot elevation.
I have ran stock intake and the under hood intake and temps are about the same. It makes more boost and feels stronger on the under hood intake. I tried the 275 flash and it did the same. The intake temps just get super hot, keep in mind in washington we are riding in the 25-35f degree air temp most days. I might clutch and tune this thing for climbing on the 275 flash and just use the 300 on trails, With a little lower boost i might experience more consistent power delivery. It makes massive power on the 300 going down the trail when the intercooler has flow. Keeps the skis off the snow past 75mph lol. You might be right on the 8500, i do know there is a huge difference in power between 8100 and 8600, somewhere in that area she really comes alive. I would bet it make more power at 8900 than it does at 8100.
 
Hurricane built a very smooth 300header tune for sure, Makes huge power on top end. I would like to see a dyno on the 275 header tune vs the manifold tune to see the difference in torque. It felt like maybe more mid range grunt on the manifold tune vs header and built boost quicker on manifold tune but the header tune kills the manifold tune up top without any doubt.
 
Check out this thread some good info:


 
thank you sir, looks like i need that intercooler to solve my issues, or at least help.
 
intercooler ordered!
Im on the fence about just going with the straight race intercooler and CR Racing light weight hood and putting a fan in there. The lower intercooler doesn't do much other than pack with snow and turn into a 20 lbs ice block in the mountains.
I did see one guy get a intercooler core from an automotive shop then he fabbed the end caps himself and mounted it under the hood with good results. He also moved the turbo back, built a new fuel tank and put the alpha plastics on as well....
 
The McXpress is great for removing heat!

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