I have to agree with Saki’s post. When it comes down to it the 4.2 doesn’t have the limitations the 2.7T does on stock internals. Simply put, where the 2.7 falls off the 4.2 keeps going.
As far as the comparison of stock block capabilities the 2.7 is doing quite well. I don’t think the 4.2 limits are known yet, but let’s say the 2.7 is nearing its max @ 600 chp. That’s approx. 222 hp/liter. For the 4.2 to put that ratio on the stock motor it would have to pump out 933 hp.
^^ D lo thats exactly what I was referring to. Hp/liter on paper comparison. Obviously that means nothing in the real world though. Especially since they weigh close to the same amount.
When the hot weather returns , I will be assembling a single turbo on my RS . Hoping to have 500 to 550 hp to the wheels. So I’ll let you know if it stays together.
lolwut?
Pretty big job. Can’t wait to see who tunes it!
Where are you thinking of locating the turbo? If you don’t want to share, that’s entirely understandable.
Battle of the boosted V8 FSI… J-spec turbo vs JHM supercharged vs APR supercharged vs TTS
in for info
…for you Saki
Don’t tease us Jnaut, you can’t bring these kinds of things up an then disappear like a fart in the wind. Good luck though, looking forward to your setup and placement.
LMAO!
I will get Into details later, but all parts have been purchased and preliminary layout is handled. As for tuning I will be leaning on Jhm/ Kurt hopefully.
I went to +150 hp with nitrous . Engine ran great.
Stock rods and pistons can get you to 650 hp engine hp .
Dynamic compression ratio of the rs4 can be modified with help of variable intake and exhaust valve timing.
TTS is winning at the moment, but we’ll see what the future holds ;D
LOL
Well will have wait and see!
Well, I can report in:
The RS4 motor I am pushing has given me its’ limit. I gave the engine a “little extra” boost with the Rotrex blower and “BAM” ! The EPC function kicked right in to protect the engine. I was at 7,100rpm and the engine pulled the shute. At first, I thought I had blown the engine. Instead, the engine made a massive cut off and the car limped in to “tree hugging” mode. Drove back home w/o pushing it, and eventually it semi-recovered, and it ran like N/A stock. I guess I pushed it a little too far? My brakes are pretty messed up and I can honestly say the engine did a better job than my rotors LOL. Tuning this thing is a PITA…
I concur. Me too! Im looking at some big brembos for my next mod
How much HP is on the MRC tune? 600? 625? My brakes are completely inadequate…cant imagine how much worse it would be with your power!
[quote]How much HP is on the MRC tune? 600? 625? My brakes are completely inadequate…cant imagine how much worse it would be with your power!
[/quote]
I am not comfortable with the data we are getting from the engine, too early to give accurate/consistent readings. Right now the engine has tourette’s syndrome and I am not going to give out B/S figures.The engine is all over the place. With this said, MRC has posted very conservative numbers in our opinion, perhpas the British Isles has worse weather than our Florida humidity??
I don’t get it…epc light? What bashes you think that was a safe guard by the motor because it was being pushed to its limit?
Could be a bunch if things. Moisture in the ecu even. Was it raining? Had you been to a car wash?
was there any eml or epc lights on before the engine pulled the chute?, just cause it sounds like you hit the hard limiter at 7000rpm you get when the epc light is on.
a few of us in the uk have had the sticky manifold flaps problem, the tumble flaps sensors would record the flaps being in the wrong position and throw the eml light, after a while and more wrong positions being recorded by the sensors it would throw the epc light and impose the 7000rpm hard limiter(sounds crazy when you hit it especially with the non res milltek i had on at the time, i can see why you thought you had blown your engine).
obviously these sensors are now redundant on the tts manifold, are you sure these have been coded out correctly in the mapping?.
im no expert and probs way off but i just thought id mention it.
can doug not shead any light on it?, im sure he must have pushed dannys old car quite far(he had permission to blow it lol) before they settled on the 620ps figure.
p.s first post! ;D
Welcome sar, good input. For those who don’t know sar has an amazing RS4 (Avant?) in the UK with full JHM exhaust. Sat bit sure you noticed, but the guy who sold you the exhaust has already ditched the I’ve gee replaced it with. Guess the comments that he was being hasty were bang on. His loss, your gain!
There are indeed a bunch of things that could have caused what sobers4 described, and your post is a great example.
Sobers4…you mentioned a little more boost…how is that? Different pulley?
What octane were you tuned for and what was in the tank? I think you are in Florida right? So altitude is not a concern. Octane on fuel in the UK vs here is obviously not the same. Ron and Mon numbers can be disparate, even from the same company.
Sar:
Good to have you here! I appreciate your valuable input and I will report back when I get a chance to plug the car back in again. Currently I can only speculate what is going on and I do not want to ruffle anybody’s feathers until I get the facts. The EPC light now illuminates as soon as I push the engine and turns off shortly thereafter. I will certainly send Doug the codes for his input as well. We’ll have her fixed up in a couple of days.
Sakimano: There are a few gas stations down here in S FL with 110 octane and I just couldn’t resist. ;D. Normally I run 93. BTW Sakimano, you are up in Canada right? Send down a coldfront please, we need some cold dense air down here.
It wasn’t raining and no car wash.
Have you looked into the codes for yourself?
http://www.obd-codes.com/trouble_codes/audi/
I know I had my light come on and after I vag-com’d it, revealed some random periodic misfires.