Comparing APR Stage 3 to JHM Supercharger Kit on the B7 RS4...

B6/7 S4/RS4
#1

So since these Supercharged cars started to hit the track I’ve pretty much made my decision that I will be searching for a very clean low mileage RS4 to purchase in the next year or so… IMO the AMD kit is something I would never buy and the TTS Kit is made overseas and I personally wouldn’t strap on a 10k+ blower from a company in another country on my daily driver expensive Audi.

Leaving two good viable options, APR and JHM. There has been a lot of discussion and multiple threads about this but I’d like to break down both kits pro’s and con’s and also every modification done to each car. I will only discuss the full weight, pump gas runs as I feel they are the most ‘realistic runs’.

Based off of the results and pricing which one would you chose? Both companies are very well proven and have shown to be reliable over the years so I think either way you can’t go wrong. One thing that I don’t like is how APR will not release a solid number on boost, whereas to my knowledge the JHM kit runs ~8psi…

APR’s run:
DA was -58

Modifications:
APR Stage 3 Supercharger Kit
APR High Pressure Fuel Pump Upgrade
JHM Stage 5R Clutch and Flyhweel Kit
Magnaflow HFC’s in stock diameter
19" TSW Wheels (46lbs) on street tires
K&N Drop in filter
93 Pump Fuel and Full weight

Best run:
60’ was 1.654
1/8 ET was 7.2
1/8 MPH was 99.02
1/4 ET was 11.156
1/4 MPH was 123.11

It seems the APR car has a no lift shift program and also launch control.

JHM’s run:
DA was ~+200

Modifications:
JHM Supercharger
JHM Stage 5R Clutch and Flywheel Kit
JHM LW Crank Pulley
JHM LW F+R Rotors
18" Wheels (~46lbs) on street tires
JHM 2.75" Catless Downpipes with 2.75" Catback
JHM Intake Spacers
91 octane and Full weight

Best run:
60’ was 1.697
1/8 ET was 7.215
1/8 MPH was 100.131
1/4 ET was 11.12
1/4 MPH was 125.755

So given all the information above it seems like the two kits are giving very similar results, the JHM car is slightly more modified however the APR car has upgraded fuel pumps and also is probably running a little more boost. I’m guessing probably somewhere between 12-14psi on 93…

Do you guys think the motor will be okay in the long term at those boost levels?

I’m a fan of both JHM and APR, however given the information above I think I would opt for the JHM kit over the APR for a few reasons… Those reasons being it’s probably cheaper, it’s faster and quicker on stock fueling and 91 octane, and at lower boost levels it’s probably safer for the motor in the long term…

I do love how both companies are doing testing on the track rather than a Dyno and I think that with the same supporting mods on both cars, and both on 93 in good conditions they can both go 10.9X and 125+MPH…

Sorry if some of this is repeated stuff from other threads but I thought it would be cool to look at both runs next to esch other and seeing how close they really are, rather than all the information being scattered…

If their are any errors in the modlists feel free to correct me guys…

JHM Slip:

http://i1219.photobucket.com/albums/dd440/Auditude20T/f36a30e1ef9cd45e7754ea702946502b_zps7676553a.jpg

APR Slip:

http://i1219.photobucket.com/albums/dd440/Auditude20T/8cf2dadd26f2253ccaa8bc56f6fcc8f4_zps23596834.jpg

#2

Look at it this way, RS4 owners are lucky to have TWO good options. In the early days of the S4 supercharged programs, we had TWO horrible options!

Consider yourself lucky to have this dilemma :slight_smile:

#3

Same with the RS4, the PES and VF options early on were both fail… Honestly I wish I would have kept the RS4. When I took it off my dads hands I only kept it for so short because my friend had offered me top dollar for it. Then a few months later he sold it again… If these options were around back then I would have hung onto it for sure…

It’s crazy how the platform has evolved, crazy how different these cars are in terms of the aftermarket in comparison to the domestics…

#4

Auditude, there’s an error above. JHM is making 8 psi of boost on that 11.12 @ 125 pass, and APR appears to be making 14.3 PSI according to their boost gauge readout yesterday. This is post intercooler.

Also, Axel I wouldn’t discount TTS as an option. I know you were just making a comical reference to the horrible SC kits we endured in the S4 game, but just to clarify something with respect to TTS for the thread. Their kit is excellent and of the big performance kits, is by far the most widely owned. There are a dozens I believe, with up to 2 years of customer experience. Granted they’re overseas and that’s a vald concern for us here, but there are not TWO good options. There are definitely THREE and for those who like Addict there are FOUR.

Back to APR vs. JHM, it’s virtually identical. Pretty funny to look at it. Both cars had their advantages and both cars had their disadvantages. From what I saw:

APR’s biggest advantages are fueling, boost and Density Altitude.

JHM’s biggest advantages are exhaust, more LW rotating parts

At $12,000 I think that will be the biggest differntiatoin for JHm. APR has hinted that they will be $15,000-20,000.

Both kick ass, and both are great accomplishments. Think about the B5 in context…a superstar accelerator and the benchmark against which all subsequent performance modified Audis have been measured. No B5 is ANYWHERE near these achievements with this type of street setup.

#5

Tough choice. I think it’s a wash. But I’d probably go for JHM just having had their tune before. I think the Count really really knows his shit with the tuning side of things. Just an encyclopaedia. His energy and enthusiasm are infectious too! They all came from a domestic V8 background which I think helps in this scenario. There is some epic attention to detail. And they’re the only ones to really put an emphasis on supporting mods like exhaust. All so you only run the boost you need.

And there’s too much APR going on in your neck of the woods lol

#6

I would go JHM based on the tuning alone. I’m not taking away from anything APR has done, but if another company can do the same with less boost and stock fueling, chances are the calibrator really knows what he is doing. The same calibrator that pulled more NA power out of the BHF and BNS 4.2ls than anyone would have believed a few years ago. He was also so successful with the platform that APR reached out to have him oversee and help with their 1320 kit tuning when the kit was not meeting their projected goals.

Also look at some other things the JHM kit will include…
6 rib LWCP and supporting hardware. (I wonder if APR changed the design of the belt system? Maybe you can ask Arin in the APR thread) this alone is a $600 value.

The JHM stage 1 will also probably cost half of what the APR kit will cost, and for less money you get a company that basically made themselves a name on these cars (B5S4, B6/7 S4, B7 RS4)

#7

I wrote 8psi for JHM. The 12-14 guess was for the APR Kit but I must have missed that 14.3psi reading for the APR Kit.

#8

Excellent work putting all this information together in one thread! Really makes it nice to have both slips and documentation of exactly how each car was run right in one place for comparative purposes. I was very impressed with APR, not only the times they ran, but also how they detailed exactly what was done or not done to the car for each pass. Their kit looks to be very well thought-out for this platform, it is obviously well tested, and it will come with the backing of a topnotch company. That being said, I will go with JHM. I think they have also created an excellent product. I like that they run their kit with a much lower boost level then the other. I like how driven the company seems to be in manufacturing and providing solid parts for our cars, and I really dig Jake. You just can’t ask for much better customer service.

#9

Very well said!

#10

Don’t forget saki Manu’s argument thread
http://audirevolution.net/forum/index.php?topic=499.0

Lots of historical perspective!

#11

Great thread, Pete (as well as Sak’s thread). Really cool to see how similar the results are with the two different approaches.

APR may feel the pressure to reduce the price of their blower. Otherwise, I guess they could just buy JHM. That would be an interesting merger.

#12

That would be an Epic team…

JHM and APR together…

#13

One thing to also think about is just the “fun factor”. In a 1/4 setting they’ve proven to be very equal. But I’d wage to bet due to the s/c type used the APR one puts down more Tq and more instantaneous neck snap at lower RPM’s. Just a guess since my JHM kit felt VERY linear. Just like it was NA but with more power.

I think both kits are awesome, and price/customer history is go with JHM. But I felt it was probably worth mentioning. I know linear power is better for track and more predictable, blah blah blah, but sometimes it’s fun to be a hooligan and get that neck snap feeling like big turbos spooling up. Just for the grins, but the apr kit obviously delivers as well as provide grins.

Anyhow, it’s awesome to see multiple legit kits available, ESP for such a small market and aging market. Even cooler to think about this kit on the RS5 and R8 though!!!

#14

Idk, the S4 kit was held back due to the engine, not necessarily the supercharger. It would be interesting for you to get a ride in one to see if there is indeed a difference in low end torque.

We also can’t forget that JHM re-gears the supercharger so it probably doesn’t lack much compared to the top mount blower.

#15

APR is pretty big…but not that big.

#16

lol at this comparison

Go get a ride in the JHM stage 2 RS4 and then tell me what you think.

#17

Haha, okay. Make that happen and I’ll be happy to give feedback. Hey my car was violent down low with headers and I loved it! The RS4 has the better gears too so I can only imagine. I was just speaking on the principal of how each s/c works. The cent. builds boost gradually where the tvs is much more early on.

APR claimed 550whp/585wtq didn’t they? On the S4 where JHM claimed ~430whp it was somewhere in the 350-400 wtq range. So just saying the APR unit should produce a good bit more Tq. Unless that was a fueling issue from the getgo. Also I’m not smart enough to speak about longevity/health of the different power profiles etc, so not factoring that in at all.

#18

I think if you want to quote APR’s numbers on race gas etc…you’re missing the point. You will never be a passenger in someone’s car with race gas and no catback because nobody drives like that so lets get more realistic.

On the APR pump gas tune, they mentioned around 500 whp and I can’t remember the whp…but they showed it here. It was around 375-400 if my memory serves me correctly. Same as TTS and their cfuge. Same as AMD and their 1900.

Knowing that JHM was trapping 125-126 with their pump gas setup, do you really think they’re going to be making much less torque than APR? I don’t.

#19

^ didn’t realize those were race gas numbers. But I was under the impression the JHM kit was around 525-550whp as well. So I figured the APR kit was also. Again, just based on blower dynamics, I assumed the TVS would make more TQ earlier on than the centrifugal unit does.

I had kinda understood that Stg II S4 = Stg I RS4. (With Stg 2 S4 being around 550whp).

#20

93 oct actual dyno numbers SAE corrected 525whp/490lbft. I’ve seen as high as 536/502, but a standard heat soaked pull will achieve 525/490. That being said the 104 file put down 600/540 uncorrected and 585/525 .

Be careful racing dyno charts. I can show you Hondas that trap 130mph on pump and don’t make more than 350lb ft, peaky powerbands tend to trap higher, but don’t ET as well.