Porting cylinder heads has been the way to more power since there were engines!
It has shown that MOST heads, aftermarket or stock, WILL increase power potential when massaged, ported, and a performance valve job added!! If your head is an "out of the box unit", the power output can be increased with port work! How much power? Our Clients have found Anywhere from 18 to 35 WHP on the MINI S with STOCK Tune and ECU settings and 58 to 65 WHP with ECU Tune with stock size valves.
· Why get a “Racing Head” when you don’t race?
· Want more power for the aggressive drives and weekend track day, and don’t want to sacrifice most of the low to mid-range power for the daily drives to work?
· Want better MPG for the freeway drives?
· Just want more power?
· Sure you do we all do.
The Flow Number is the amount of air the ports will flow, at a certain cam or valve lift. The larger the Flow Numbers, the more RPM is needed to get the power from the heads. That upper RPM may hurt the lower torque numbers and throttle response, for the daily commute and when off boost!
We have found two things make for a good head! Flow volume AND velocity! The velocity of the air is what fills the chambers, which allows the engine to build power. The faster the air speed, the quicker the power is made! And this is where the low to mid range power is critical. The flow volume will allow power through the mid to top end.
There are a number of ways to build flow. The first is to port. The second is to install larger valves (+ 1.0mm or +1.8mm), which is also good. However, if the ports and valve size are too big air will become "lazy" or slow moving, which causes slow, sluggish low speed response!
The way to increase the air flow is to run a higher engine RPM, to build up the flow speed (velocity). A big-valve head may run great on the top end. But... under 4000-4500 rpm… it is a dog. Lazy air movement at the lower RPMs kill the daily drive fun as the low to mid-range power is sacrificed for the higher RPM power many track only Coopers need.
We think a great head for dual purpose (spirited street and occasional track) should have crisp throttle response, snap off the line on a mildly modified engine (pulley, CAI and exhaust.) Pull hard and strong to 6800-7200 rpm. We have found that VELOCITY and Flow Numbers give our clients just that and more. How do we get that done? Keeping the stock valve size and doing a 5-angle performance valve job with a “flow cut” on the valve! The 5 angles act as a boost to the air flow as the valve just leaves the seat, and also when the valve is just about closed. This increased low-lift flow allows the air to fill the chamber faster. The faster the chamber is filled the faster and more power the engine will make. Then when coupled with custom PORT/throat/bowl work the Head will keep making power till you lift off the gas!
Since no one head fits all demands we build track heads in a different way. More about that soon.
"Still breaking things in, so I'm taking it a bit easy for now, but I've gotten on it several times and it's very, very nice. It actually chirps the tires shifting into 2nd at WOT and redline, which it never did before. One of my biggest complaints with the Shrick cam was the peakiness of it - nothing below 4000 RPM's, then all the power from there up and then falling on its face above 6400 RPM. And, a major, major dip in power between 3K and 4K rpms. While Jan's tuning did take some of that out and improve driveability, it couldn't take it all out.
With the current setup (TPR-1 and NS2), the dip between 3-4K RPM's is gone. It keeps pulling all the way to redline - and I think it would keep going, so I'll need to get that bumped up. No more drop off! Part throttle acceleration is crisp - full throttle is greatness. It actually pulls everywhere, even down low, although the fun really starts at 4000...." Team TSW
“The mileage, when I keep my foot out of it has gotten better! The first week I had it I saw about 23mpg, naturally because I was beating on it. However: On the way up to Thumper's, I saw 27.3 mpg from Tampa to Jax. That was with many (5 or 6) 75-120mph passes. On the way back, between Orange Park and Ocala, I saw 28.7mpg (calculated by filling up and dividing the distance) Between Ocala and Tampa, According to the OBC I saw 28.1 That is better than the car was stock.”
Posted SSM 12/06
( Aussie Dynos read extremely low as to the Dynos in the US!)
Hi Mike,
I went to another dyno day and wow it must be the Aussie dynos!!!!! My car was putting out 140kW (without meth injection), there were other cars there with after market heads and they only managed around the 130kW mark!!!!! With the meth my car is putting out mid-high 140's. One person in particular only put out 133kW and he had spent 3 times as much as me and has a full racing set up!!!!!!
So this makes me feel much better! LOL! Sorry to stress you out!!!!!!!! Your head rocks and all is good!
Thanks
( edit!!)
... few days later...!!
Hi Mike,
I found out what the other heads were at the dyno day and I have included 2 of their dyno graphs, the third guy would not give me a copy because he had the shits! There was a Cosworth stage 2 head, a mini madness stage 2 head and a local job polished and ported with 1.5mm oversized ultric valves. All had shrick cams. My head kicked ass and at half the price! ( Thumper Performance Head TPR-1) Check out the torque curve of mine compared to the 2 others! No wonder mine pulls like a bloody elephant!!!!
One very happy Aussie!
Thanks Mate!!!!
(edit!!)
... and finally…
Hi Mike,
I thought I would let you know what is happening down under!
I got my car tuned by some guys who finally know what they are doing and the car is putting out 163kW (without meth).
The guys at the shop think that with larger injectors and the water meth on and running properly that 170kW is possible....(the water/meth jet is too big and I need to get a smaller one but that is another story)
WOW!
163kW equates to about 220hp and this is on an Aussie dyno!!!!!
On one of your American ones it would be putting out a lot more probably more than a RMW head!!!!
YOU ARE A DEAD SET LEGEND MIKE!!!!!
One of the reasons why you see manufactures show a range of power estimates. Look at it this way: Lets say you bolt on one of his heads to a stock motored mini. Lets entertain ourselves and say he picked up 12whp on the dyno. OMG this head must not be that great only 12whp. What you have to understand is that when someone like Thumper says his product will make 18-30hp, its pretty much implied these days that you have the supporting mods to take full advantage. Since this head breathes better, the engine is now being limited in power production because of the exhaust / intake and tuning. So take the same scenario, but the next car has headers, cat back a cold air intake and a 15% pulley. Lets say they pick up 20whp. Now this same head rocks because the person was able to take advantage of the extra flow that a head provided. Lets change it up a bit. Lets say you were in the stock mini that now has the head added. You go out and see the pulley claims a 7-10whp increase. So you add the pulley and dyno again and pick up 15 whp. Wow how did the pulley do so much? It is because the head took advantage of the extra air you were putting in the motor. If I had to do all of this over again, I would have done the head first. Even though its not the cheapest mod, it is one of the best for the money. Aside from the pulley or nitrous will you not find a better bang for the buck for this car. The bottom line is that the head will make the most of any mods that you do. If you start with that, you will see much higher gains for each mod you do since those mods will likely work better with the better head.
Here are the results of Ported Thumper Performance Head on my 04 Mod’d MINI. Quarter mile time dropped from 15.4 et’s @ 93 mph to a 14.9 @ 96 mph. Of course the 60 fts were as usual.. bad!! (edit: Wheel HP went from 187 WHP to over 211 WHP ( 240+ BHP !) see Dyno run. ) Thanks Thumper .
Yesterday I had a new head installed on my 06 Cooper S, and the shrick swapped over to it. The car is freaking unleashed! The seat of the pants dyno says that this thing is unreal. Prior to getting the head done my best pull was 196.4whp/173tq with the following mods: JCW injectors/ecu software, shrick cam, megan header, milltek exhaust, Random Tech cat, Alta CAI, IC, 17%, 0% lw crank pulley. Next weekend I plan on getting it dynod at my usual dyno just to see what kinda numbers it is putting down. I can happily/sadly say traction is an issue in first gear! ( Those results were 225WHP )
Post on NAM 12/06
I already had the laundry list of mods and just wanted to be above the 200whp net. I definitely think I have surpassed this, but we will see next weekend. 2nd gear has crazy pull now, and 5th and 6th on the interstate will get you around just about anything. I cant wait till the next track event to see how the low end jump helps pull out of the corners in 2nd!!!
Posted SSM 12/06
TPR-2 VS a RMW Head ...... The TPR-2 head with 15% pulley, Janspeed manifold, JCW CAI,stock cat back and newman cam - generated the same hp/trq curve as : RMW head Janspeed JCW CAI 15% stock cat back newman cam combo.
***** Independent Dyno run in the UK, by an independent Shop (1320 Auto )
Independent dyno UK 05/11/09
"Just letting you know, your head made 276bhp with a 17% pulley with ambient temps of 22c. don't have all the figures. I’ve asked them to see the difference with a 15% pulley, may get more power at the top end and still have pretty good torque.
One of the dyno runs made 287bhp but was never reproduced due to temperatures going too high.
"As some of you aware Mike sent us a head to do some testing and see what we can get out of it in the way of performance on the dyno and on the track. As you can see from the dyno sheet comparing the RMW head and tune on Big Shows car and the Thumper head and a Chris tune on 1320’s Mini. We still need to do some more testing off combos as and when we can but we have achieved the following so far."
( Note: these numbers were with a bad ECU!)
******This car has gone 11.70's on a 80 shot of Nitrous
UPDATE: Car Has NOW Gone 11.16 @ 123.10 MPH and is the Fastest "Super Street" MINI in the United Kingdom
The power is right were we want it.. " the Sweet Spot" HP- 2500 to 7100 revs/ Torque- 2100-6800 revs