I tested the Riva intercooler today

[Green Hulk]

It wasn't the back to back test I have been wanting to do though.

I got off work early and came home and switched out intercoolers. I really thought the Riva IC would perform better so i put a 80mm nozzle in the venturi as i was banging the limiter with my 81mm the previous weekend.

Got out on the water and I was down 100 RPM's on top. I think this is directly attributed to running the 1mm smaller nozzle. I should have left the 81mm nozzle in for this test

One thing I did notice was acceleration was better and the boost on my gauge was one notch higher. My top speed was down to 76.9 down from 77.7 with the RR IC last weekend. Again, i think this is due to the 1mm smaller nozzle.

So now what I think i want to do is yank the pump, put a hair more pitch in my prop. Put that 81mm nozzle back in and go back for a run with the Riva IC. Once I get my results then I will switch back to the RR IC at the landing to note any differences.

I really don't anticipate seeing much of a difference to be honest. Nonetheless, im going to back to back test them anyway.

I was really hoping for astounding gains

[Shibby1485]

well it's results, no matter how disappointing it may be! seems to me also that after tweeking, you will probably be at the exact same speed maybe? The boost increase is a good indication tho. the intercoolers are a seemingly drastic different size and totally different build and material composition. defintiely expected a dramatic difference between the two, just wasn't sure which way it was going to swing.

[amirmiz]

I waited to this test for a lot of time.I am still waiting to the results of the back to back test . in the next two weeks I intend to buy the riva intercooler .or the back to back test will say otherwise...

[Green Hulk]

I hope to do the back to back test on Monday if the weather cooperates with me.

[amirmiz]

I also hope for a good weather for you .you can come to israel ther is a good condition in our lake now.

[Green Hulk]

I bet it is very hot and sunny over there!

[Pale Rider]

Boy, am I going to have questions about intercoolers, when I need to get one...Of course you know I`ll be asking you again Jerry! ...PR...

[Green Hulk]

I'm beginning to think i shouldn't even be testing these two right now. They should be back to back tested in the heat of summer to give accurate results.

[Pale Rider]

I agree, since it`s job is to cool the incoming air charge effectively. I think hull temps would play a dramatic role if you are looking for precise results...

How`d I do with that amswer Jerry! ...PR...

could the boost pressure differential, be attributed to the materials, volumetric efficientcies, design characteristics, and air flow stacking behind the throttle blade when on and off the throttle, hence one of your quests in seeking the values of the 2 intercoolers being tested, blah, blah blah...

[Green Hulk]

I think the increase in boost is attributed to the bigger inlet/oulet of the Riva IC.

One other thing to consider is if the air is moving faster then it may not be given the opportunity to cool as much as it would if the air was moving slower.