mumzer

thanks

Alan C.

A friend installed one on his car and his manifold air temp, MAT, was less than my stock intercooler. Both cars using Tec3's and similar turbos. The slope of the rise in temp was also less on the Lindsey unit.
Alan

Danno

Alan, which Lindsey intercooler was this? Any temperature numbers comparing before & after? Thanks -danno

Ski

I've been pleased with the Stage I intercooler. I have no temps to publish but I did like the flow numbers on Lindseys site with regards to pressure loss. The car felt a better after the install on spool up,,maybe just from less pressure being lost from the inlet being enlarged..?

Pannan

A friend of mine had the Lindsey stage I installed in his car. The spool up was significally better than stock.

Another friend just took the stock IC and re-welded the original sides. He´s spool up is also much better now. Maybe a 1000-1500 rpm increase than stock.

//J

David Floyd

</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Another friend just took the stock IC and re-welded the original sides. He´s spool up is also much better now. Maybe a 1000-1500 rpm increase than stock </font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Wow! That is a great improvement, can you give more details on what was done?

Weissach Vampire

I had my intercooler modified on both sides, you can see it compared to the original IC <a href="http://groups.msn.com/porsche944sverige/minporrsche.msnw" target="_blank">here</a> . Haven´t had the chance to try it yet due to winter in my area...

I did it mostly because i wanted to try to minimise spool-up, sounds like i am on the right track <img border="0" alt="[jumper]" title="" src="graemlins/jumper.gif" /> .

dmoffitt

impressions of my stage1 lindsey ic:

cooler air charge (simply, i can put my hand on the pipe going to the TB now, couldn't before.. ow!)

quicker spool (at least 300rpm i'd guess).

a worthwhile upgrade at a minimal cost compared to buying a totally different intercooler, and extremely easy install / perfect fitment. plus, dave and mike offer excellent customer service & support (when i bought the intercooler, the sent me 2 boots + clamps faster AND cheaper than my local porsche dealer could get me a single boot).

Danno

While I can see their stage-1 providing less of a restriction and pressure loss, how can this reduce temperatures? Heat transfer is a fixed property of contact surface area and time. If you flow something through the intercooler faster, it won't cool as much... you have to increase the surface area.

Ski, don't you have an infrared heat gun? Maybe you can do some before & after intercooler temp readings. But it'd be tough to do this while driving the car huh? I gotta hurry up and finish our intercooler in/out gauge...

Andy

It could be that the restriction from the factory was also hindering the equal dispersion thereby limiting the contact area...

Alan C.

Danno,

I'll post some numbers on Friday. I left my laptop at work.

My friend is using the new Lindsey unit not the refurbed Porsche unit.

Alan

Ski

</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by Danno:
[QB]
Ski, don't you have an infrared heat gun?QB]</font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">I do. I'm going down to the "Mustang Dyno Ranch" a week from Monday to see how the new injectors and chip work. See if we can cross the 300 barrier. Hey, do you have any ballast resistors for the injectors yet? Email with $$ requirements.

I'll take some temp readings on the inlet pipe to the turbo and both intercooler pipes and record the temps. I'll also check the exhaust manifold to see how the Jet-Hot is holding up with regards to the first drive temps.

Sean Hall

</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by Danno:
<strong>If you flow something through the intercooler faster, it won't cool as much... you have to increase the surface area.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Danno,
If you increase flow, delta t increases too.

-Sean

dand86951

Not sure about all the physics involved but I tried to do an objective benchmark test. Made several two way runs using third gear only, starting at 40 mph off boost going to 100 mph. Got an average time. Drove back into the garage changed out the intercooler to the stage I. Went back to the same road, had to adjust the boost down a tiny bit to get the same boost, ran the same test. Results, a 4.6% decrease on 40-100mph times and a 2.7% decrease in 40-80mph times and this was with the outside air temp up 4C on the later runs.

Danno

"If you increase flow, delta t increases too."

But that's only if you increase flow of the cooling medium on the OUTSIDE of the intercooler. If the ambient temperature was say.... 70F and it flows at certain velocity through the intercooler, it may be be heated up to 100F by the time it exits the rear.

Increasing this flow velocity of the outside air will flow more volume through the intercooler. So yes, you can increase the cooling effect because a larger volume of air has flowed past the intercooler. But each individual piece of air has been heated less because it has been in contact with the intercooler for a lower amount of time. That means delta-T at the rear of the intercooler is greater because the cooling air has been heated less as it's traveled through the intercooler faster (it picked up less heat). So overall delta-T (between inside & outside) is greater with higher flow (velocity & volume) because the air at the rear of the intercooler is only 80F now.

However, the converse is true on the INSIDE of the intercooler because you've got higher velocity for the same volume resulting in less time at the same transfer rate. Let's say you have the same conditions; the same volume of air flowing through the inside at a certain CFM at the with same RPM on the turbo coming out at the same 250F temperature. Let's say we have two identical cars with only different intercoolers of the same size and contact surfaces, with the only difference being one is less restrictive than the other (outside temps and velocity the same). From the heat-flow equations, we get total heat transferred as:

joules = watts*t = t * [kA(dT)] / d

where: k is thermal conductivity to transmission medium
A is cross-sectional area of transmission medium
dT is delta of temperature gradient (T1 - T2)
d is distance heat has to travel
t time of contact in seconds

We can see that for two intercoolers of the same material and size, the heat transfer gradient is the same provided the outside ambient temperatures is the same. Everything can cancel out and we can just use watt*sec to compute total joules extracted. The more time contact is made for any individual piece of air, the more energy is transfered out of the intake charge.

Another example of this is if you were to double the size of the intercooler. For the same CFM flowing through that larger intercooler, each cubic-feet of air will flow through at half the speed thus allowing more time thus more heat to be extracted at the same watt*sec rate.

" Drove back into the garage changed out the intercooler to the stage I. Went back to the same road, had to adjust the boost down a tiny bit to get the same boost, ran the same test. "

With lower restrictions, the same boost will result in higher CFM flow. I'm not saying the Lindsey intercooler doesn't work better, because it does. But it does so by removing a restriction to flow, not necessarily by better cooling.

In order to quantify temp-drops, you have to equalize ambient air as well as intercooler-in temperatures. Higher ambient temperatures will result in higher intercooler-in temps, thus may make delta-T a wash. I think the only real way to measure that would be with a temp-in/temp-out gauge and correlate that with outside ambient temps.