44 replies to this topic

[piwo]

you perfect control the car.

Congratulations.

[Firthy]

I have heard from the problem with the engine temp when using the pro alloay radiator for intercooling.
The dual radiators would solve this problem.
If you just want to stay on stage 2 SC then I think the WI is a little over powered.

It cools down the IAT by evaporating the injected water. You can measure a big decrease in IAT.
But the biggest amount of cooling takes place inside the engine when the air gets compressed.
At these high temperatures the water takes a lot of energy out of the air with its phase transition.
So the combustion can run much more effective and the EGT drops about 80-100°C.
The wohle engine runs much healthier. You could also drive a leaner mixture because you dont have to cool down the engine with your fuel.

Thank you that seems to be the consensus that WI is overkill, when moving to the two rad solution are the louvers a necessity because of the air flow into the arch? Or can you just run the cut outs at the front bumper?

[Nev]

How on earth do they machine the block to insert the decking plate so exactly. Must be an interesting process.

[fezzasus]

How on earth do they machine the block to insert the decking plate so exactly. Must be an interesting process.

 

Easy with a computerised programme that creates the inverse shape of the deck plate. 

[Vladimir]

Impressive job, you did what I'm dreaming to do for several years already!

 

May I ask the size of the Setrab coolers you're using and could you share some sketches of the cooling box and mounts if you have them? Would help to save lots of time on re-inventing it.

I wonder also why did you connect them in parallel? I’m thinking on putting them in series and make flow the same way as the cooling fluid flow goes.

 

May you also share contacts of “Tobias Kroll from "KT-Fahrzeugtechnik”, I’m doing B207 preparation right now would be nice to get it girdered as well at the same time.

[alexb]

I asked myself the same thing about the parallel vs serial set up. Luckily Setrab (and Mocal) actually publish performance graphs of their products. In a parallel set up, you half the flow through the radiator, but have the same delta T (difference between ambient and coolant) for both radiators. In a serial set up, your flow is the same through both radiators, but you have a smaller delta T for the second one. If you look at the graphs and the trade off between decreasing flow vs delta T, it's better in cases with sufficient flow to maximize delta T. Which means parallel is better. 

 

[Vladimir]

Well, looking on the "cooling effect per tube" (Setrab graphs) I see that the more flow gets though the tube the better is heat rejection.

When in serial the flow is constant, but in parallel it halfs the flow i.e. that heat rejection will decrease as well.

 

I assume that Setrab Series 1 should be used due to the limited space, then difference is not so big, but exist anyway.

[Vladimir]

I asked myself the same thing about the parallel vs serial set up. Luckily Setrab (and Mocal) actually publish performance graphs of their products. In a parallel set up, you half the flow through the radiator, but have the same delta T (difference between ambient and coolant) for both radiators. In a serial set up, your flow is the same through both radiators, but you have a smaller delta T for the second one. If you look at the graphs and the trade off between decreasing flow vs delta T, it's better in cases with sufficient flow to maximize delta T. Which means parallel is better. 

 

Right, further it depends on temperature diferrence, and in parallel it will be bigger. 

 

Solved.

[alexb]

To get total heat rejection you multiply with delta T. See their example calculations. So total heat rejection is linear with delta T and when you look at the heat rejection per tube graph, you'll see that the curve goes almost flat with higher flow. As an example, assume you use a Setrab series 1 25 row cooler. Which I think is used in this case. To make it easy, assume a 25 l/min pump is used, which is quite common. That's 1 l/min per tube tube. Looking in the graph, heat rejection for 1 l/min per tube for the series 1 is approximately 2.2 W/C/tube. For 0.5 l/min it's 2.0 W/C/tube. I did some calculations and although the difference is very small, serial turns out to be better, as the actual temperature drop is small. I expected that drop to be much more, in which case parallel is better. But again, the difference under practical conditions is small 

 

 

[FLD]

I guess the other delta T is in the laminova. You need cold(er) water or a longer dwell. Many years ago I used a Lockheed heat exchanger I sourced from a missile. It was a cryogenic system. I plumbed this into the air con system for charge cooling. The path length was short at 50mm and it really hammered the AC which obviously saps power. The end result was it didn't work too well. I've recently seen killer-chiller systems where people have plumbed the AC into the charge cooler circuit. I'm guessing this does the opposite of heat soak in that it could build up some cold water. Not sure how it would fare on track where there is high load but it could work quite well on a road car. I'd be interested to see peoples opinions.

[FabianG]

As you said, the bigger the delta T, the bigger the heat rejection. 

Thats why you do the dualpass thing in the back. To have 2x a big delta T. 

If you look at just one tube and the delta T along the tube is small or lets say 0, then you wont have any heat rejection. no matter how fast the fluid flows. (that would be the case at the end of a very long single tube).

So the bigger influence is the delta T. Thats why the tubes on the radaiator itself are ordered in prallel instead of in series. 

You would do even better if the four laminovas in the back would all be connected in parallel. And even more better if you could let the fluid flow against the air stream in the intake manifold.

But thats not poissble, sadly. 

 

I could imagine that the dual radiators in the front could be really effective if you modify the intake manifold to a 4 way parallel laminova system.

If I had no WI, I think thats what I would go for.

 

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To the AC thing: thermodynamics wise that wont have any positive effects. Maybe for a first short time because of the inertia of the system.

But the energy that is necessary to run the AC wont be gained with the resulting drop in IAT. 

 

Its like you want to cool down your room by opening the fridge. Just in a more complex way. 

 

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Sadly I dont have any sketches of the cooling box. I built it directly on the car. 

And you will find out that you have to build every side on its own because the car or the crash box isnt 100% symmetric. 

 

 

 

Edited by FabianG, 21 January 2019 - 01:06 PM.

[Rosssco]

Great project Fabian! Watched your Racelogic TC review a couple of times..  

[mementaurum]

Fabian, what can I say...fantastic job, great clear pictures.

[FabianG]

Great project Fabian! Watched your Racelogic TC review a couple of times..  

 

Thank you ! Yes, it was a lot of fun to do those videos

 

 

 

Fabian, what can I say...fantastic job, great clear pictures.

 

Thanks mate !

 

-------------------------

 

A few more pictures of my suspension

 

I did a complete freshup last year. Drives better than new now   

 

 

 

 

 

 

Edited by FabianG, 22 January 2019 - 12:59 PM.

[Dan r]

It looks better than new as well!
Very nice


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[gozer 1.4]

A few more pics from the front radiators

 

 

 

 

This bar connecting the two toe-links, where did you got it?
Could you please share more picture of it?

 

thanks a lot

[mementaurum]

Is your car "Miss January" on the German Opel Speedster Calendar?

[FabianG]

 

A few more pics from the front radiators

 

 

 

 

This bar connecting the two toe-links, where did you got it?
Could you please share more picture of it?

 

thanks a lot

 

 

 

I got this bar with the toe links from Dempert-Automotive. Sadly they don't exist any more and you cant order any parts from them. 

The cool thing about these toe links is the "forked mountig" (do you say that in english ?) on the subframe side. These mountings send the force into the bar which is mounted under preload so that there is less elastic 

bending of the subframe before the force can be absorbed in both sides. (Sorry, but difficult to explain in english). 

 

 

Is your car "Miss January" on the German Opel Speedster Calendar?

 

My car was a few times in the german clandar. But sadly I missed to send in any pictures this year.  

[Firthy]

Can I ask what charge cooler rad setup you were running before you moved to the twin Setrab?

Just trying to understand whether or not I would get a reduction in IAT vs the standard pro alloy setup?

If I can cure the engine temps and get better IATs it's a no brainer!

Edited by Firthy, 27 January 2019 - 10:21 AM.

[gozer 1.4]

 

 

A few more pics from the front radiators

 

 

 

 

This bar connecting the two toe-links, where did you got it?
Could you please share more picture of it?

 

thanks a lot

 

 

 

I got this bar with the toe links from Dempert-Automotive. Sadly they don't exist any more and you cant order any parts from them. 

The cool thing about these toe links is the "forked mountig" (do you say that in english ?) on the subframe side. These mountings send the force into the bar which is mounted under preload so that there is less elastic 

bending of the subframe before the force can be absorbed in both sides. (Sorry, but difficult to explain in english). 

 

 

 

Thanks for the information.

I'd like to find that bar.

Do you have any more picture to share regarding this bar setup?

Thanks a lot