AutoX hood alterations.

[spyderdrifter]

Well I think I got a good idea of what I'm gonna be doing for my hood. However, I thought of another matter, and don't really want to start a new discussion so I'm putting in here since it's related.

I've seen many questions and answers regarding under-hood temps with the FMIC blocking air flow to the radiator. Has anyone ever considered reversing the set-up and placing the rad in front of the FMIC? I'm quite sure the same problem would exist, only with the FMIC instead of the rad, and consequently would end up with hot air entering the intake instead of cold air. Would this ultimately be worse than the higher temps of the standard set-up? So all are aware, I am in no way considering this something viable enough to attempt on my car. Just more ideas. I think in the end, I will be doing a tubed frame anyway and possibly do the rad and FMIC in a 'V'-mount orientation to help enhance air flow through both cores.

 

[jtmcinder]

The target temp of the radiator is 200*. The target temp of the intercooler is ambient. You always put the heat-exchanger with the lower target temp in front.

 

[spyderdrifter]

Or else the lower target temp goal is never reached right?

 

[Diamond Star Werks]

your radiator stays,as hot as the coolant flowing through it. Do you want IATs at that temp? Yes you want the lowest target temp exchanger in front.

 

[spyderdrifter]

Spiffy... this is what I had guessed anyway, just needed the right clarification.

 

[LandoAWD]

I did the hood spacer, we verified a 20' temp drop after on run with the spacers installed. They work great for me

Why is the airflow of every other DSM, including tufted/tested ones on this very forum, so different from yours? Can you substantiate the claim?

(This is my diplomatic way of saying "bullshit")

People hate on the spacers because they are 1/100th of the price a vented hood will cost... and by all means the coolest dsm has the most money in it.

We "hate on it" because it looks like you wrecked the car and now your hood doesn't fit...and, oh yeah, it doesn't work because of the pressure differential.

 

[Diamond Star Werks]

They don't call it cowl "induction" for nothing.

 

[ViciousLord]

They don't call it cowl "induction" for nothing.

Exactly... Induction not Extraction. By forcing air in where is it going to go? Down. Which will create lift.

Cowl Induction hoods are great for carbureted vehicles where fresh air is being introduced to the filter element.

I think the main idea we're trying to achieve here is Extraction of heat. Not induction of fresh air.

 

[kamikazeredneck]

Exactly... Induction not Extraction. By forcing air in where is it going to go? Down. Which will create lift.

Cowl Induction hoods are great for carbureted vehicles where fresh air is being introduced to the filter element.

I think the main idea we're trying to achieve here is Extraction of heat. Not induction of fresh air.

This is exactly right. When you have a cowl induction you are drawing air from the windshield which is cooler than under hood temps usually are. When you have cowl induction you are pulling air into the filter from the windshield.

If you are trying to extract heat then one of the best ways is through a radiator of some sort. You want to get as much air to pass over the radiator as possible, which in turn cools the coolant and then the engine. You are not cooling the engine by having air pass over it unless you have an air cooled engine. The raised hood may be helping put cool air into the engine bay but the easier way that has been tried and true is to put a vent in the hood right after the radiator. This not only keeps the heat that you just extracted (from the radiator), out of your engine bay, but also keeps the vent in the pressure zone of the air trac, and it will help draw the air out of the radiator while air is being pushed it through it. It is like having a puller fan and a pusher fan moving air through different parts of the radiator. This then keeps temps down because the radiator is working much more efficiently essentially doing it's job more completely.

 

[cait sith]

Just put an external oil cooler on the car and leave your poor hood alone.

 

[kamikazeredneck]

Just put an external oil cooler on the car and leave your poor hood alone.

This is also a good option. I added my oil cooler (and mounted it in a location to get direct air in and out of it) and my temps were staying right where the factory had them set (203-206*) with a stock radiator, slim fans and a big FMIC. I never saw them go high once and I have taken it up hills, pushed it in 115* heat and everything and no problems. Just do the proper turbo, downpipe and manifold wrap and you should have no problems. I am currently re working my cooling system because I want it to work at its best efficiency level and so a lot of modifications need to be made but most people just need to keep it simple unless you are running 500+HP.

 

[spyderdrifter]

I forgot about all the heat wraps too. My power goal is just anywhere between 450-500. I achieve that, and I'll be happy. Probably don't even need that much for autocross, but that's the goal.

 

[snowborder714]

That's way too much power for an autox build.

 

[spyderdrifter]

350hp more ideal?

 

[snowborder714]

Much more ideal. And that even still may be too much.

You basically need to get out there with a car and learn to drive first. Then build your car around what you feel needs changed and/or what class you want to stay in if you're concerned about being competative. My car sits around an estimated 300hp and I dialed down the boost for when I went to the autox. The boost just hit too hard, too fast and caused me to spin the wheels, as well as just be too out of control. But this is a discussion for a different thread.

 

[spyderdrifter]

Sounds good. I agree, meant for a different discussion to which I know there's a lot of good info on here about. I've read through some of it. Won't go off topic.

 

[jtmcinder]

The key is that shooting for 450 hp is going to mean getting the wrong turbo. What matters more to autocrossing is having as broad a torque curve as possible. The height of the peak is almost irrelevant.

 

[spyderdrifter]

I've been planning on a 16g with supporting mods. Will be focusing a lot on handling and cooling.

 

[Diamond Star Werks]

I would say a good s16g would do you well in autox with a properly built engine. As it would have a more optimal spool time giving a better overall power curve.

 

[cait sith]

Honestly I'd get an LSD/Suspension suspension suspension before a turbo for autocross. DSMs are fat enough and have enough issues throwing down power before worrying about adding more.

 

[jtmcinder]

+1 I only got the T28 and water injection after the Konis had hats and plates and real springs. And I probably should have gotten diffs before them, too.

 

[Scott McIntyre]

Likewise, I did all my suspension mods before upgrading from the T25 to T28 for autox.

Then I focused on front / center / rear differentials.

Now I'm more focused on time attack, so my next power upgrade will be in the 500HP range.

 

[spyderdrifter]

My car has a Big T-28 on it already. Got lucky to have bought it like that I do want to upgrade the suspension and stiffen everything with the fender braces and other parts I've seen.

 

[cait sith]

T28 + Stock cooling system is more than adequate for autocross.

I'd focus on learning how to drive the car before spending more money.

I don't know about you, but I find it more embarrassing when you have a big money sink and it's still slower than the lower classes.

 

[spyderdrifter]

T28 + Stock cooling system is more than adequate for autocross.

I don't know about you, but I find it more embarrassing when you have a big money sink and it's still slower than the lower classes.

Agreed on the slow part. I got an upgraded radiator since my stock one was clogged.