PERRIN Turbo Inlet Hose and 08 Intake Test and Tune

This test was done on our 08 STI shop car.  Before we get to far into the fun stuff, the STI is in our Stage 2 form. This means it has our twin cat downpipe, 3” quad tip exhaust, and our Stage 2 AccessPORT tuning.  With that said we are going to show 2 tests in this article one, the PERRIN 08 intake and the PERRIN  Version 2 inlet hose.

First lets explain the dyno and testing methods we are using.  In Oregon, we have 92 octane, using that fact, in stock form our put down numbers a little higher than 91 guys but a little lower than east cost guys. But still our 235WHP was pretty similar to what many people are seeing.  Our dyno we are using is a Dynapack dyno.  This isn’t a dyno that reads high, or really low.  In fact it seems to be pretty close to the mustang dyno in how it reads for most cars.  All of our runs are done in 5th gear, and run for 14 seconds.  Both of these factors play into the actual HP and TQ numbers we see.  These factors are important to mention and important to understand as they can be manipulated to change the results.  We could have made the dyno read a bit higher, by changing to 4th gear, or making the run shorter, but for tuning purposes, and future part comparos, this is what we decided on.

The new intake system is different than other silicone versions we used to make. We are moving more toward all aluminum intake systems in general on old and the new car. So this is the first all aluminum intake you will see from us.  Using our newest MAF housing design, which incorporates a partial velocity stack into the front, we have a simple tube mating it to the OEM inlet hose.  What is different about this intake as well as the future ones, is that its ONLY a cold air design.  The filter is located down in the fender behind the fog lights and where a nice fresh bath of cold air is constantly passing by.
 


First up we did some runs and a little more tuning to our Stage 2 mapping.  With that said we had our base line before we installed the intake system.  Initial testing on our intake system showed the MAF curve was pretty close to the same as stock.  Our first couple runs show that it leans out the AFR’s almost 1 full point.  For a tuned car this is not good, for a bone stock car it is good.  With that said this intake will be one that requires a custom ECU tune.  Our intakes in the past didn’t have this issue, but this could be do to the change in the new MAF sensor, or the change to the intake housing.  Either way we will be selling this as an ok part for a stock ECU tune, and a custom tune required for a car with an AP.

 
Our initial results with the car running leaner were very good. But it was on the verge of being a little dangerous for the off the shelf mapping.  Also since the intake made the car run leaner, this doesn’t prove that that intake being freer flowing makes more horsepower.  This is important to note as we do not want to trick everyone into thinking our intake make more power than others.  So in order to keep things all square and equal, we retuned the ECU to the same AFR as our stage 2 tune. This way the gains shown are gains from the intake flowing more air, not from MAF trickery.  What is strange is that with out retuning the ECU we were seeing about the same power!  Adding back in the fuel only caused a loss of about 3-5HP.


 
Even with all that said, 20WHP on stage 2 PERRIN map is huge!  One other thing to note is the boost.  Boost was the same before and after the install.  Below, the green line represented the boost we saw.  So what created that purple line??

 
The above Purple line is when we installed the PERRIN version 2 inlet hose!  This is not something anyone (that we know of) have done back to back. Some have done back to back, but not in the same day or week. Now that we have a dyno sitting here we thought, why not!  After we were done with the intake hose and testing we thought, lets install the inlet hose and make a video of it! This would show how easy they are to install and be the quickest back to back inlet hose dyno runs ever done!

37 Minute install started out because I said “I bet I can do it in a half an hour!”  Now it had been quite a while since I had install one, but now I had a camera taking pictures over my shoulder, the challenge was on! After the install was all done, I was surprised that I did it in 37 minutes!  I think had I been a little more prepared (should have grabbed a part off the shelf) and with a little practice 30 minutes is totally doable.  Since I had John h taking pics of the install over my shoulder, we turned the install into a quick video.

 
As described above, the results that really surprised us was the change in boost. This proved 2 things. One the stock inlet hose is a restriction holding back the turbo from spooling up. And the other thing it shows is how much freer flowing the inlet hose is above 5000RPM.  Where the ECU built more boost at low RPM it created more TQ, and where it added more boost above 6000RPM it also added more HP. Funny, more boost equals more HP???

 
The dyno runs all showed the same thing, not much change in peak power, but about 10WHP gain up top and a 100ft-lbs gain at 2700 RPM!  This is only because the boost came on quicker.  After driving the car, the low end is very noticeable, as is the top end power compared to the stock intake system.

Another thing to note is these results are still with the stock TMIC and stock headers!  Oh, and don’t forget 2 cats in the PERRIN Downpipe!  I bet you can guess what items are being tested next………

The PERRIN inlet hose used here is the newest version of one of our best selling parts ever.Lots of good info on the Evolution of our PERRIN inlet hose can be found here.  The biggest change to our Turbo inlet hose is the new skeleton.  Our past hoses were all constructed the same, where the multiple layers of silicone and polyester created a stiff hose.  Its gone from 4 layers to 5 layer to help the stiffness stay in check.  To this day roughly ten out of thousands of parts were returned to us with the collapsing issue. The issue was due to the silicone not being cured long enough. While this was a very small issue to us, it was publicly exploited on the Internet and made out to be a much bigger problem that it really was.  Again, this small issue could be completely remedied if we made a simple and effective change.  Our new skeleton now included a steel wire running through the part.  So there we have it!  Along with this, some slight revisions to the included pieces, and instructions were done.  We feel that these changes will make an already great part even better. And with ZERO change in price.

That was kind of a one 2 punch for dyno results, so I hope its not too much to take in.  Its nice to have solid HP gains to show customers both intake and inlet hose gains.  Look for more dyno results with headers and intercoolers very soon!