Turbo options for Built EG33

[cdigerlando]

I was running about 60 C or 140 F intake temps with very high ambient temps, around 95 F. I'm sure this was knocked down a bit by the water injection. This was using my tec 2 intake temp sensor. I don't think anyone will get intake temps down to 100 degrees with 95 degree ambient temps no matter what your boost level. With an intercooler the boost the turbo sees is higher due to the backpressure caused by the intercooler. This must be considered in the equasion. So if you have 1 or 2 psi of loss across the intercooler this will need to be added to the turbo boost when calculating the temperture from its rated efficiency. That is why pressure drop across the intercooler, as well as heat transfer efficiency are both important factors to consider when picking an intercooler/turbo combination. Thus there is a break even boost level below which an intercooler is not really helping all that much. That is why I didn't do one yet, and why the supercharger kit did not have one when they only planned to run about 7 psi of boost. I did plan on installing an intercooler and raising the boost at some point. Intercooling will be the next thing I do. In fact, while I am breaking in the motor I will keep my boost levels around 3 psi with the water injection comming on at just above 0 psi. Then when and if the motor is running well I will dump money into an intercooler. I will be able to measure intake temps with the Tec 2 so I'll let you know what I come up with with this turbo. I may also change turbos and increase the exhaust to a full 3". We will see how the funds go.

[Phast SVX]

I was running about 60 C or 140 F intake temps with very high ambient temps, around 95 F. I'm sure this was knocked down a bit by the water injection. This was using my tec 2 intake temp sensor.

I am more concerned with when you were running before the TEC. You ran the car on 5lbs of boost with zero timing and only a RR. I have seen it myself, their is no timing for positive manifold pressure deinsity on the stock If i recall correctly, the car did not run correctly and detonated, or knocked( or maybe it was kastles kit). There was no doubt damage done at that point to the piston. Also, the Head gasket issue is consisnt with a hot spot situation, which occurs most often in relation to detonation or pre-det on one or more cylinders. I am not trying to be a poop, just saying what I have read.


I don't think anyone will get intake temps down to 100 degrees with 95 degree ambient temps no matter what your boost level. With an intercooler the boost the turbo sees is higher due to the backpressure caused by the intercooler. This must be considered in the equasion. So if you have 1 or 2 psi of loss across the intercooler this will need to be added to the turbo boost when calculating the temperture from its rated efficiency. That is why pressure drop across the intercooler, as well as heat transfer efficiency are both important factors to consider when picking an intercooler/turbo combination. Thus there is a break even boost level below which an intercooler is not really helping all that much.

You have the intercooler theory backwards. Yes, their is a pressure drop. The drop in pressure is due to the cooling of the air. Cooler air is more dense. Therefore. this is by no means a backpressure. You make power by having high density, not simply high pressure. 5psi of dense air will produce far more power then 7 psi of hotter air. If you have an internal gate you can turn your boost up to compensate for the pressure drop if it worries you that much, but you will have more power unless the turbo is large and on low boost pressures. We have small turbo’s, running ridiculous shaft rems. If you have an external gate, you can feed your pressure line to the intake manifold and not worry further.

You do not get a negative pressure field prior to the intercooler, and therefore cannot have backpressure against the impeller unless you have a 90 degree crush bent pipe directly after the impeller, or far too small of piping. The only time your intercooler is a restriction is if you have not properly measured and fitted to your application. Notice my intercooler core is thick, 3 ½ inches if I recall correctly with 2 ½ inch end tanks and ic piping. This is not an admirable trait, as the front 25% of the intercooler face does 75% of the cooling. However, I have a low boost pressure and am not worried about a large cross section, as long as I get a reasonable density increase and proper flow.

[ZephTheChef]

The drop in pressure across an intercooler is a GOOD thing...in some cases, may even create "less" backpressure on the turbo than if it wasn't there. I can definitely see the point as far as saving money goes, considering the low goals you set for that particular setup (boos pressure wise)...but for any serious reliable power, you've gotta have that intercooler(s). The resistance it adds in the intake piping is negligible next to the fact that the air is denser. True, on a very small turbocharger where you only intend to run a very small amount of boost then the gains are not so great, but when you are talking about any serious kind of power (in my opinion, why even go through the hassle to only add 30-50hp?) the cooling drastically outweighs any restriction it could provide.

I make no exaggeration of my goals for this car: 500awhp and/or 11s as cheaply as I can manage. I will certainly report the number of miles I get on that setup, whether it be less than 1 or more than 10,000. Damn, I'm getting excited about this, wish I didn't have to wait until mid January to pick up the car.

[cdigerlando]

Originally Posted by ZephTheChef

in some cases, may even create "less" backpressure on the turbo than if it wasn't there.

What cases are these? An intercooler is an obstruction that will have pressure head loss across it. I could see how having a reduced volumetric flow due to a drop in temperature (caused by the intercooler) would have less loss through the manifolds, but unless it is huge, you will almost always have more pressure drop through a system with an intercooler.

Please research this issue further. This is not some unsubstanciated claim that I alone am making. There is also discussing regarding this issue at nasioc. More recently this was discussed in the built motors forum.

[Phast SVX]

I honestly cannot think of one car I have tuned out that made more power then the same rig without an Intercooler. Most of which fall in this catagory ar 7 psi or lower straight T3 powered stock B16's running chrome or hondata. You of all people with 95 degree ambiant temps would have the most to gain out of all this.

I hate going over the the Nasioc Forums. For every person who may know something, five babble on. I talk to the people that I want to via PM when I have a question. Additionally, half the people with built motors cannot get them to even turn over, much less run they way they should.

You want to remove a majority of your "obstruction" for the intercooler that you are claiming is factor at low boost settings? Buy one with proper endtanks. Better yet, buy one that has a lateral matings with angled cores and vertical tube and fins. You cannot beat the fluidynaic chareteristics of this design. Cross section utilization is much higher as well.

Now we are back to crappy intercooler designs causing the flow restriction, or obstruction as you like to call it. I have about a psi and a half of pressure change with my setup running the wastegate signal line off of the impeller housing instead of the manifold tap with the lightest "big" tial spring in my 38MM wastegate. As i stated before, my core is thicker and therefore, has less cooling capacity. But as I said before, my rig dosnt need it.

Everything is relative.

[cdigerlando]

Originally Posted by Phast SVX

I honestly cannot think of one car I have tuned out that made more power then the same rig without an Intercooler. Most of which fall in this catagory ar 7 psi or lower straight T3 powered stock B16's running chrome or hondata. You of all people with 95 degree ambiant temps would have the most to gain out of all this.

I hate going over the the Nasioc Forums. For every person who may know something, five babble on. I talk to the people that I want to via PM when I have a question. Additionally, half the people with built motors cannot get them to even turn over, much less run they way they should.

You want to remove a majority of your "obstruction" for the intercooler that you are claiming is factor at low boost settings? Buy one with proper endtanks. Better yet, buy one that has a lateral matings with angled cores and vertical tube and fins. You cannot beat the fluidynaic chareteristics of this design. Cross section utilization is much higher as well.

Now we are back to crappy intercooler designs causing the flow restriction, or obstruction as you like to call it. I have about a psi and a half of pressure change with my setup running the wastegate signal line off of the impeller housing instead of the manifold tap with the lightest "big" tial spring in my 38MM wastegate. As i stated before, my core is thicker and therefore, has less cooling capacity. But as I said before, my rig dosnt need it.

Everything is relative.

So if you are running 1.5 psi drop across your intercooler, and lets say you are running 10 psi of boost measured at the manifold, you would be looking at the heat produced by the turbo producing 11.5 psi not 10. I think that is the difference. I'm not saying that the intercooler does not help, what I am saying is that the benifits become minor. You are right about intercooler design. Some give way too much loss, and/or don't transfer enough heat. So a good core design is a must. An air water might almost be better for a low pressure turbo. Less losses across those. They just heat soak easily.

I think we are beating this to death.

[ZephTheChef]

I'll concede the point that it's mostly a waste at very low boost...however understand that without removing the internal wastegate flapper (or unhooking the actuator from it at least), the LEAST amount of boost I can run on my current car is 11 psi so you can see why I love my intercoolers. The SVX when I build it, will be the same way (I'm too poor for external gates).

Plans have changed a little and I might be able to go pick it up a little sooner. I will hopefully have some pictures for you guys by mid January so you can see what a beauty I'm starting with.

[Phast SVX]

I run the signal line off the turbo 99% of the time. So I am not runnign the heat of 11.5psi. I like a nice dense charge, the cooler your running the more timing you can run, and that comes into play with a high compression motor with a very tight squish area. I would assume you have a J&S or something to catch knock. in which case you will loose quite a bit of timing, if you have your sensetivity set default.

I just dont agree with what you are saying, we are running high compression with boost, not low compression with medium or high boost levels.

[cdigerlando]

Originally Posted by ZephTheChef

I'll concede the point that it's mostly a waste at very low boost...however understand that without removing the internal wastegate flapper (or unhooking the actuator from it at least), the LEAST amount of boost I can run on my current car is 11 psi so you can see why I love my intercoolers. The SVX when I build it, will be the same way (I'm too poor for external gates).

Plans have changed a little and I might be able to go pick it up a little sooner. I will hopefully have some pictures for you guys by mid January so you can see what a beauty I'm starting with.

Yes you will definitely get a lot of benifit from running an intercooler with 11 psi.