Engine 1st Gen Next step in my Modding

There are some good threads on Thumper heads over on the side of the Pond. 1320 is a British Tuner that apparently has done allot of tuning on all of Thumper's heads.

I had Jan at RMW tune my car when I installed his cam and 450 injectors. Since that time I have gone to a 19% pulley ratio, a header with a 200 cell cat and meth injection system that I am not using for tuning but rather cooling the intake manifold temps from the 19%. Any of the larger valve heads have different valve springs so the Rev Redline can be increased. The issue with increasing the Redline is that will there be a point where an injector may have a maxed out "duty cycle" and with the 450's that is probably more than a possibility.

The 19% provides better low end torque but at higher revs the heat developed can cause premature detonation. IMO I addressed that for my driving habits by installing the Meth injection. I keep stressing that I am not tracking or do autocross.

To get the most benefit from the larger valve heads you need to push that redline but I am not into bragging rights and to push the redline it might be best to remove the 19%. The 450's duty cycle also come into play here so at this point I am thinking about leaving the redline at 6,750. I will still get the benefit of more torque and will not be pushing the supercharger even more. I have my ultra gauge set to monitor the O2 voltage outputs. On this subject, a voltage of .045 is equal to a F/A of 14.7:1, a 0.1 is lean with 0.9 being rich. Remember that the OEM O2 are narrow band sensors and do not provide Lamda outputs.

Jan did the tune for the cam and injectors and it would appear the ECU can address the additional air flow relative to A/F. I plan on logging the O2 voltage prior to the swap and then will watch it when I have the new head installed. What I see will determine whether I pursue another tune. I push redline in 1st gear and then in 2nd on mountain runs. I will hit the limit in 1st but have not in 2nd. The 19% will address low end torque, the head will increase the total torque and the horsepower will also be increased. Tracking would expose the supercharger to long durations of high rpms and also result in higher intake temps. The instances of doing this on my spirited mountain do not exist and the loss of any top end hp due to lover revs is not going compromise the fun I am having.

 

On pulleys, here are some spreadsheets that reflect pulley ratios, motor rpms and supercharger rpms.

 

When I start a thread of this nature I always hope that some good discussions result and that is just what is occurring. I am not into asking somebody what color of car I should purchase or whether I should use all-season tires. There are some very informative posts here. How many people when thinking about a head change also realize that injector size and fuel pump pressure/volume are going to be involved?

I have spent allot of time around MINI forums over the past two years and cannot remember seeing current good discussions on these type of matters. The Gen1 is a car that was developed almost 20 years ago. Technology has not stopped in that time so many older posts on any of these types or issues are loosing their relevancy.

 

Any forum is a microcosm. There will be those "for" a particular item/part/procedure and those "against." Being involved with NAM in an Admin/Mod position, I was privy to information that many people have no knowledge of. Internet Brands (IB), which owns NAM, also owns 130 other auto/boat/atv/motorcycle forums. Their perspective on a forum community relative to participation, topics and the dynamics of a forum are very interesting. Through years of forum ownership and analyzing forum participation, they acknowledged that there was a 1% rule. This rule is that of all those that visit a forum, only 1% become involved enough to create posts. Nine percent of those that visit will join and participate in "consuming" the posts made by the 1%. The other 90% visit but leave.

As noted previously, Mini Torque has allot of information on the Thumper heads. There is data posted that reflects horsepower/torque gains that one would associate with porting/polishing and larger valves. IMO there is enough of this information for an individual to make up their mind on what path to take with a head change. This data also reflects how the variables of intakes, cams, exhausts, tunes and temperatures all impact actual data recording. There is even variables relative to the type of device used for the collection of data.

In a competitive atmosphere it would be logical to assume that an engine component with very strict tolerances would be able to function
better than something "crafted" by human hands. Such is the case with a RMW head versus a Thumper head, but unless the person is looking for bragging rights, is the tolerance factor enough to justify the additional cost between the two?

The answer is of course that some will agree and some will disagree . . . . . .

 

I take very good care of my MINI but it is 10 years old and has over 60,000 miles on the mass produced engine that it came with . An engine that by no means is balanced or blueprinted. The car goes as fast as I want to go on the twisties that I frequent. Do I need more horsepower and torque, no, but I want it.

Now just because I want it and even though I have more than enough money to put the most expensive stuff made on it, I will not. I just cannot justify paying for that finely machined CNC head when a "crafted by hand" unit will do just fine for allot less money. Yes the machining has made each port just about the same, sorry nothing is exact as there are tolerances involved, but my pistons, rings, crankshaft and bearings are by no means worthy or requiring the CNC tolerances.

Not looking for bragging rights, just looking to have a grin on my face.

I ordered the ported intake today from Thumper and he is going to send me some pictures of the process that I will post here.

 

If I could turn back time, and take my MINI with me, I would just love to drive it to high school and then do a drive from Cazenovia to Chittenango on Falls Road. The guys I knew that had MoTown Muscle cars would just be sitting in their cars with their jaws wide open and a look of total amazement on their faces.

In 1972 my Flyin Pig MINI would be a Supercar.

 

So which Thumper head did you buy?

 

Thanks for replying as actually trying to get some real consumer type thoughts from those that have had either let alone both is so much better than just opinion.

From @BlwnAway it appears he had both heads. He also had the cam gear that Thumper Heads sells. Thumper will time the gear for you as well.

 

From what I have been able to find it appears the torque curve of my RMW Dominator cam starts around 2200 rpms with the OEM valves. The bigger valve heads will push that value up more toward 3000 but it also appears that if the cam timing is changed just a little with a cam gear I will be able to get the torque back down toward 2500 rpms.

I am not planning to increase the redline at this time. My type of driving benefits more from torque than HP at higher revs. I talked to Thumper and he thinks he can tweak the Dominator with his Cam Gear to get me down to 2500 when it is matched up to his TPR2 head.