hally

thanks tedesco, great data.

toddk911

Taking before and after boost readings?

I would like to know how many psi are lost through the IC.

Also, would shed more light on having the wastegate line before or after the IC.

tedesco

Pressure drops are next on the list. Don´t know when it will be ready.

I though of rather upgrading the engine in this car. I still have a 3L lying around with short rods but I´d rather go for propper low compression pistons. Any good sources?

The background of the measurement was to prepare a more radical step in improving another car. Some time ago I bought an intercooler of a tank. Had something like 35L displacement and was turbo- or supercharged. The intercooler is completly made from aluminium and for its size it is quite lite. It already has some propper 100mm flanges on in- and outlet....
I thought of cutting it to size and installing the water radiator in the back which is good for wheight distribution anyway. now I might keep all like stock (at least for some more time).
Currently I am running a Lindsey S75 with all the other usual bit installed. The turbo is actualy too big for the (2.5L) engine but still must be very efficient otherwise the compareably low compressor outlet temp could not be explained. Also have some propper Garrett stuff lying around... it is just the time that I am missing.

Perry 951

I also have plans for mapping pressure drop logging 2 MAP sensors. I gotta figure out how to bung the pipes though...

toddk911

I still feel it is better to have the WG line tapped after the IC.

Otherwise, if you are running 15psi set on your controller, when that pressure is achived, the WG opens. So 15 psi is going into the IC, but if there is a 1-3 psi drop out of the IC, then you are only getting 12-14 psi actually into the motor. If you tap the WG line after the IC, then you will actually get ALL psi that you are making into the motor. Would also explain my some have constant rich issues, since they are mapped for X amount of boost but less than that is going into the motor.

toddk911

Tedesco: I too am running the LR Super 75. And yes, contrary to what Dave L. told me, I would have gone with a smaller turbo if I had it to do over again due to lag issues.

But in the mean time, to make the 75 work with the 2.5L, I just need to run more boost and higher revs

I see 18-19 psi in 4th gear about 4,200. I have to say that some fine tuning could help spool up some I am sure, but I can't get ST to come to Orlando and tune my car

How does your spool fair?

schnellfahrer

I don't excactly get what you mean Todd.
Before or after after IC should not affect how much boost you are running.
If you are using a MBC you are usually adjusting boost based on readings from a boost gauge T'ed of the KLR line (from manifold). If your are using a EBC, it's usually also connected to the line from the KLR. Do you have a gauge or EBC attached to the line going from the banjo bolt?

toddk911

Ok.

I thought, last this topic was discussed, there was not confirmation that the boost guage that is T's from KLR was getting reading from the manifold?

Even if that is the case, how could the WG modulate the before and after pressure drop?

Dash01

The reason your results are worse with the vent open is that you've removed and/or buggered the inner black plastic diffuser duct, and in the process disrupted the internal flow. This thing expands in height as the air flows in, allowing the incoming cooling air to slow and compress, making for better cooling flow over the IC fins, with less drag in the process. NACA did a lot of optimizing work on this for WWII recip engines of fighters and bombers, and ALL of their test results indicate that better ducting and exit ducting is the way to go. Trying to just ram more air in at a sloppy inlet is poor procedure, and can be counter-productive, as you've discovered.

What you really need is not the extra inlet duct (with commensurate buggering of the inlet diffuser duct), but a better OUTLET pathway to allow smooth passage of the cooling air back into the slipstream.

Optimum point for this is just above and behind the IC, at the rear side of the header panel. That is a low pressure/high velocity point for the slipstream over the nose. An aircraft-type cowl flap at that location is the answer.

Corleone

How can the efficiency be 80%. Isnt it 68%?

You take away 95 degrees C from 140, 95/140=68 or?

If it is 80%... will it not be 140*0.2=28 degrees C after IC?

With a good IC you should not have moore than 30 on a 20 degrees C day. Stock is no good even if several people here has made much hp, with a better one they would have made moore...

Perry 951

That's what I get too. 45/140=.321 or 68%
Interesting that I see 65% on mine. Can the stock duct really account for 15%? Anyone have a stock duct in good shape they want to sell me for testing?

Laust Pedersen

At the very least an efficiency definition should be independent of the units used. The boundary numbers would be 0% if there is no temperature drop and 100% if the temperature drops to ambient.

A heat exchanger’s efficiency or effectiveness is usually calculated as (T1-T2)/(T1-Ta); where T1 is the inlet temperature, T2 is the exit temperature and Ta is ambient (cooling flow) temperature.

Plug in the numbers and you’ll get 80%.



Obviously you’ll get more HP with a more efficient IC. The question is how much HP increase for how much effort (bang for the buck).

Laust

RKD in OKC

I tested the LR stage 1 and stage 2 intercoolers during a test and tune night at the local 1/4 mile strip. It was a hot a very muggy night. I did two runs with each intercooler. I revved to 4K rpm and dropped the clutch on every launch. It wheel hopped but the times for each of the two runs for each intercooler were very very close. Several of the regulars said I should be doing dial in.

I saw about 1/2 second improvement for each stage intercooler.

My car was a mostly stock Turbo S with weltmeister chips, shim, and Lindsey Boost Enhancer.

azmi951

Just a clarification, efficiency and effectivness are different calculations and use different parameters.

Efficiency is dependant on cross flow temperatures and mass flow rates and can be modeled as a simple system. It is something that is so heavily dependant on dynamic test conditions that it is kind of worthless unless compairing A to B or if you are always operating at steady state.

Effectiveness is a UNITLESS number that evaluates the overall performance of a heat exchanger based on its mechanical design and negates all cross flow conditions and flow rates. Some of the mechanical properties that nare needed are fin area, fin design, fin spacing, all the reynolds, nuselt and prantel numbers and convection coefficents, but it does not need any temperatures of cross flow fluids.

Effectiveness takes the variables out of evaluating a heat exchanger so it is based on only what does not change.

Let me play devils advocate and ask how do you KNOW for sure that peak inlet and peak outlet temps happened at the same time? Could there not have been some kind of heat soak that would give false readings? I dont know but I could not put my confidance in it being the same. That is the engineer in me. Also I recently had a class called "heat transfer" where we investigated this type of stuff on a more basic level. I tried to calculate the effectivness of the intercooler but could not due to the complexity of the calcuations. I used the NTU Method for seperated perpendicular flow heat exchangers.

azmi951

But dont get me wrong, I love to see this type of info and discussion, keep it up.