Made about 87hp to the wheels on a dynapak, I think my r53 throttle body may be causing it to lean out around 3000rpm then the car is dumping fuel…

I did this as a baseline before Adrian tunes the car,
current mods:
Intake with cone filter
removed center resonator from exhaust
ngk wires and plugs.
r53 throttle
6 speed swap


all 3rd gear pulls

not sure what else would cause the dip in power….

 

That's really low. I have a R53 throttle body, plus a whack of other mods (cam, header, exhaust), but I haven't gone as far as a ported/polished head. My R50 makes ~130 at the wheels. Interested to see how your numbers change after a tune.

 

My 2003 R50 does the exact same thing. It's pretty extreme on my car though. I've never had it on a dyno, but Id imagine it'd be a big dip in the curve when it falls on its face. I have a CAI, ported S head, and full exhaust. I have not had it tuned yet and I'm pretty sure its slower now than it was stock .

Hey ATK666, what cam are you running and are you tuned? 130 whp is pretty dam good for a justa!

 

Hey @JerBear I definitely recommend you get a tune, otherwise your ECU can't take advantage of the modifications you've made. I am using a piggyback system that I bought years ago (UniChip), but my tuner has the software and is able to squeeze the most out of it. I am running the Crower NS1 cam. I believe it's the one that adds more torque lower down, as opposed to more power higher up. I've listed all the mods on my page. Pretty extensive, but I don't have a bigger head, like you do. I am saving up for a RMS bored-and-stroked engine, as, with ~150K miles, mine is nearing rebuild territory, and I'd rather get a new engine than slap a header on a rebuilt old engine, and, when I do, I may try a standalone ECU and ditch the UniChip.

 

I was actually just talking to Adrian yesterday about getting mine tuned. I already have the interface and 270cc injectors. I don't have a professionally ported head, just an S head I rebuilt and cleaned up a little myself. Airflow has definitely been improved though because the car is VERY lean now (read the plugs). I burned up the crappy R50 exhaust valves on mine, that's what prompted the new head. I really wanted to put a cam in with the head but this car is very budget so I opted for the stock cam.

RMS motors definitely make power but have you considered swapping to a different platform? I am trying to get this thing up to 250k miles (just because) and at that point I am seriously looking into a Honda K24. Box stock out of a TSX they make just over 200 hp. They also take well to boost.

Here is a turn key kit from RPT. Pricey but easy. You can also just get the mounts and use a combination of Honda axles and wiring too and save about $1000.
https://rptcreations.com/products/rp...ini-cooper-kit

I plan to build it all myself from scratch as I'm cheap and have the ability to fabricate whatever is necessary in my shop. I am also researching a box stock S motor as a replacement with a small turbo as opposed to the supercharger. I do love a good naturally aspirated motor in a lightweight car though...

 

Cool. Yeah, I've seen the K-swap kits, and they're interesting, but I want to keep the car MINI (i.e., something I can just drop in and that has compatibility with my existing exhaust, etc.), and I also don't have the welding skills required for the K-swap mod. I know a RMS motor is very expensive, but I plan to keep the car as long as I'm able to drive, so it's a worthwhile investment, IMO. Hoping for 150-60 WHP with a higher redline and top speed (my car revs out at about 115 mph), and that'll be more than enough for me as I don't track the car. As an aside, you may want to shell out the ~$300 for a Sprint Booster. Really helps with throttle response and makes the car feel much sportier. Have fun!

 

Yeah that all makes sense. For the same reason I'm also considering a basic R53 motor with a small turbo hanging off the back of it. I'm not the least bit concerned with top speed personally as the fastest speed zones I ever travel in are 70 mph zones. I do want hill climbing power for mountain runs and better acceleration though. And I'm told a tune can do the same as a sprint booster but with other benefits also. I can get it tuned for roughly half the cost of a sprint booster so will probably just go that route. I'd be very curious to see how this car responds to a tune. Who knows, maybe I wont see the need for a motor swap or boost at that point.