Turbo kit component thread

Now waste gates.

Garrett has a pretty nice description with pics saves me a bunch of typing. The Mitsu wastegates are bascally the same as the Garretts. You see this question come up a lot of the times by newcomers to turbos "How do you adjust the boost on an MCX kit?". Can it be done, well yes it can. The waste gate on a Garret or Mitsu turbo is held in place by a spring loaded pot. The spring provides a range of available boost from 0 lbs to whatever. So basically all a boost controller does is spill air within the limits that the spring is set at. So if you want more boost shorten the length the wastegate rod thus increasing the spring tension, less boost make it longer. An automatic boost controller and a manual boost controller do the same thing, they its just that the automatic one is tied to baromteric pressure (pressure equals elevation) thats how it can alter the peak boost, with a manual contoller its up to you to adjust the boost for elevation, totally the same deal neither determines what your peak boost is set at they just allow you to adjust it wintin a set range depending on the controller.

http://www.turbobygarrett.com/turbobygarrett/wastegates

M5

Good post BF thats what we are looking for

M5

mattymac said:

M5, you skipped the CFM on the 2860 since it probably is one of the most common sizes on sleds today, good to have on your list for comparison!

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Fixed it, I failed typing in school.

M5

I know that there are lots of better turbos out there for sure but I think price keeps them out of the bread and butter kits. You can spend $1500- $2000 on just the turbo depending on how you spec it. Most of the companies making kits seem to be targeting price points probably with the exception of Impulse as he seems to just build what he thinks is the best at the time and they cost what they cost. So what you end up with is comapnies trying to come in under 4k 5k 6k whatever so it just doesn't leave much on the table for them which is why you are seeing turbos like the Mitsu 15G's in kits, you can buy one brand new for $649.00.

If you were willing to spend say 8K on materials and parts for a purpose built kit a guy could make a pretty skookum kit. Theres' tons of guys who know WAY more than me and I haven't looked that seriously at all the other top notch turbos out there so maybe somebody with some better info will chime in.

M5

I'll start intercoolers but I'm hoping Dave from Powderlites will jump in here cause I know he has spent a lot of time optimizing intercoolers. Simply put they are there to reduce the chance of deto and to create more power.

Might as well mention it up front here and its JMO but in the future I think you're going to see all the high end kits coming as liquid/air. In the automotive world a really good air to air with the IC in the front of the car makes perfect sense and probably will perform as well as a Liquid/Air system but on sleds in particular the Nytro you have huge packaging restrictions and its really tough to get any honest air flow through the intercooler core. Impulse and others have stood the intercooler up as in their Apex kit in an attempt to get some airflow. The MCX intercooler in the Nytro gets no air. I have vents and all that crap but they don't really work and the IC gets hot but it does fit under the hood. The nice thing about a sled is you can put a heat exchanger/cooler in the tunnel to cool your liquid air core and you have a nice consistent source of cooling. Way more predictable charge temps.

The air charge coming out of the turbo can easily get over 250 degrees f which causes the air to expand. As a result you end up with less dense air which means less O2, less fuel and ultimately less power. A good designed intercooler is a must IMO. I don't know what the effectiveness really is but I believe that the under tunnel charge tube on the MCX kits does a lot of the cooling which is likely why the 180 kit has no intercooler that and the fact that the 180 makes under 10 lbs boost. If you ever cut one up you'll see they are finned in the tube which acts as a pre cooler, so maybe chalk one up for the rear mounts.

All air to air intercoolers have pressure drop (can be as much as 4lbs), a lot more than the liquid air cores lots of which are less than 1 lb. So the boost you see on your guage taken from the plenum is less than what the turbo is actually putting out. Here's where sizing your turbo into its efficiency range comes in. If your turbo goes off the compressor map at say 12 lbs and you are running 12 lbs on your guage you are already out of the game and just making more heat than power, say goodbye to your exhaust side. There's theory out there up the ying yang on end tank design but in general I'd be inclined to steer away from ICS with squared off end tanks as the can create dead spots through the core. Most of the ones I've seen are pretty decent now days. Should your IC have velocity stacks? Well I think yes but maybe again thats just me.

One of the things a guy can check without being a scientist is how does the IC attach to the sled/engine. I've welded up a few IC's from different companies that have cracked because they weren't supported very well. They seem to all crack where the .065 end tank attaches to the 1/8" core plate. Look for good solid brackets, this especially true if you buy a low boost kit and expect to turn up the boost at a later date because while the IC will stay on at 6lbs it'll blow off for sure probably just over 10 lbs boost it needs some kind of system to attach it to the motor besides the FI boots.

There are a few different core stlyes out there like bar and plate (Impulse, I think Powderlites), tube and fin(old CPR made by Griffin) and extruded tube (MCXstyle) but they all serve the same purpose and really don't spec out much different from one another from a performance point of view. Bar and plate are supposedly the toughest most durable cores.

Thats a start, this should get interesting


M5

NM said:

I don't post much on SW anymore mostly because of the trolls, but this is a good topic and I will stay in unless it get's out of hand.

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Awesome I was hoping to draw in some expertise through civil discussion, kinda like SW used to be in the old days.

NM here is a question for you. If a guy changed the IC on an a say MCX kit from air to air to liquid air would the MCX fuel box map still work or would the extra efficiency of the liquid air whack the fuel map requiring a different controller or map?

M5