I'm new on the forum and thought I'd share my recent project. Finally my Harrop intake project is finished after a year of work! Finish looks like an OEM setup and the numbers are relatively good. Hope you enjoy! Greetings from Germany!

 

Looks real nice and stock looking like you said.

 

Is that the one that Heinz was working on at Cool Chevy?

 

Yes exactly! Heinz did the installation, tune and details, while I did the airbox/filterting part. We are now finally seeing the results that we hoped for on the dyno as well. The run with the ITB, the dyno operator lifted his foot off the gas just above 6000 RPM as my car started to smoke because it was loosing oil, so I think there would have been a few more HP at the wheels till about 6500 RPM. That is also why you see such a sudden drop in the power there too, and the run ends a few RPM earlier...

 

LS7 with the following modifications: ARH 1 7/8 headers, Katech K501 cam with springs etc., Katech oil pump, forged Mahle pistons 4.13'' diameter, and only milled heads for a compression of 11.5, plus the rest now

I also put up a one year old dyno of the baseline set up, as that was much higher than the baseline we did a few weeks before the ITB swap so we do not over estimate the gains. If I plot those two agains each other the gain is between 20 to 30 RWHP at almost identical weather conditions. Btw, our dyno here seems to be on the conservative side compared to the numbers from a dynojet...

 

Wow!

More info please.

 

Well the Hurricane is by now probably quite renowned so I won't elaborate on that. I really wanted it in my car for obvious reasons, however with filtered air. Now the stack filters have a mesh spacing of greater than 20 microns, which lets in quite large particles. Also since the filter only covers the stacks, the filtration area is relatively small, and you would suck in hot under hood air, therefore give up a lot of power. So I decided to design/analyze/optimize the airbox/filter housing myself. I didn't have any CAD data of the engine bay or anything for that matter, so at first I started the design by 3D printing parts and then optimizing from there. The toughest part was to find a design that fits under the tight hood spacing of the c6, especially with the alternator being in the way, while not giving up performance. Also I wanted the design in a way, that there needs to be as little modification to anything, without any cutting etc., as that would drive up the cost and maybe be bad for reliability/OEM look.

The airbox/filter housing was designed using state-of-the-art temporally resolved CFD techniques. Here I got to a value of less than 1.5 % losses compared to no airboxes, which considering that you loose around 1 % on wall friction alone, is quite good! At testing we also saw that with airboxes on, we had about 20 hp more than without. This is however due to the fact that the car wasn't sucking in the hot air anymore with the airboxes on, but still shows that the design is close to the optimum.

 

Awesome job.
By designing an airbox that worked, you have solved the Harrop's major downfall concerning air filtration. On my buddy's setup, we saw a loss of 100 HP when using individual foam filters. Running them open we regained performance at the track.
Congrats.

 

Thing looks great but with hood open all the heat can escape. The way I see it the header heat (some areas looks like 6-8 inches from right below headers) will go directly to the bottom of that plastic so make sure you get some of that heat reflective stuff they have out there and put on the bottom of impacted areas. Looks like you may have coated headers which is a good idea also. They just came out with some intake manifold heat sheet stuff (see in this part of forum was posted in last month - goes underneath manifold sticks with some special adhesive backing) that would be good for this purpose. Anyway great job looks great.

 

Thanks for the info! Right now we haven't shielded it yet. And yes it gets quite hot, but the carbon fibre is heat tempered to 300 Fahrenheit. I wanted to test whether it can take the abuse first, before putting on heat shields. I have been in a few traffic jams since, with ambient temperatures above 90 Fahrenheit, oil temperatures above 200 F and coolant temp above 230 F with the hood completely closed, and so far there is no issue in the paint nor in the weave. I've tried to deform the boxes with my hands when hot, but they are still rigid.

I think the traffic jam is the worst case scenario. At the track if you go hard, you may see higher coolant and oil temps, but the entire heat is convected away from the head wind you get under the hood. At some point I will probably still put heat insulation there just for peace of mind...

 

Thanks . Wow, 100 hp is a lot, I would've never guessed that. I thought those filters will cost between 50 and 60 at tops on a 7l.

 

That is good stuff does not get soft when hot. This is not an issue while the car is moving as cool air will be going through it at a decent pace. The second reason I would put the shield in after you have tested it, is actually just sitting at a stop light or at idle/low engine speeds when the air would have time to get hot since that looks like a large plenum above the headers. Good luck with this project looks exciting.

 

Oh my.

 

I'll take that as a compliment, thanks

 

From my understanding this looks like a setup that's likely to get real hot real quick. Maybe it's time for a world challenge hood to promote heat extraction!

I also have been watching these intakes over the years and it seems that nobody can make the tune work really well with all the individual plenums to manage. Looks like you're on the right path here!