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Ever since I first seen under the hood of the PSD back in 2000 I have always wondered about the design of the spider on the turbo cold side. The hot air is leaving the turbo threw half of the spider which would heat the spider. After running threw an intercooler the cooled air runs back threw this same heated spider then down into the heads. Isn't the one piece spider slightly defeating the intercoolers purpose? Wouldn't it be better if these pipe were separated from one another?
Second question while we are on it, is the spider restrictive at all? I haven't had one out to look at it closely at all. it would be easy cheesy for me to build a new separated spider.
I took mine off to work on the turbo, and while I had it off I polished it out. I don't know how much of a difference it made as I didn't do any sort of Flow measurments. But what I did notice was a change in the pich of the sound come'n from my 38R. Kinda nice too..
Second question while we are on it, is the spider restrictive at all? I haven't had one out to look at it closely at all. it would be easy cheesy for me to build a new separated spider.
I don't think the spider will restrict any motor we will build
If you are worried about heat transfer from the hot to cold side of the spider, it can actually be cut apart with a band saw, and a piece of rubber insulation inserted between the two pieces. there is enough metal between the two sides to not give up any rigidity. there is also a $400 aftermarket two piece PVC spider, that has no supporting documentation as to any temp or flow improvements over a stock spider.
My Aerforce Interceptor scanguage is only showing a 10-15* difference between ambient and air temp at the spider with my current mods, so I don't think heat transfer is an issue with its design. I did port the inside awhile back. Doubt it made that much of a difference.
when you say port, you mean polished? I would think if you polished the inside it would flow a little nicer, pennies on the dollar results though no matter how you look at it.
Yeah you just cleaned the casting up. Thanks for the info guys! I figured the air wouldn't get heated much with how little surface area there is. It also looks pretty free flowing like you guys mentioned. It is just a simple thing to build so I thought if there are any gains to be had it would be worth it.
when you say port, you mean polished? I would think if you polished the inside it would flow a little nicer, pennies on the dollar results though no matter how you look at it.
The I.D. was enlarged slightly and the interior smoothed out. I used a carbide burr, followed by sanding rolls and a flapper wheel. Just a little time and a few bucks. Had most of the stuff already from my hotrodding days in the early 80's. Just tinkering. BEFOREAFTER
I did what Roland did, but I wasn't as aggressive at removing material. I just tried to round off the edges a bit and SMOOOOOTH it out in there. I doubt it did anything, but I couldn't help myself.