At the AutoClub Speedway race, the POC had a dyno to measure power output at the rear wheels (there is currently no maximum power spec). The top 3 qualifiers and top 3 race finishers were required to have their cars tested. I had mine tested of my own desire.
Here are three data points;
My Car: 196hp
Car 2: 187hp
Car 3: 203hp
From my perspective, its good news that my $1,800 salvage yard, never been opened, previous tiptronic, engine with 90,000 prior miles still managed 196hp at the rear wheels!
Of course, you might be wondering: with a rating of 200hp at the crank, how can I get 194hp at the rear wheels from a stock engine?
200hp at the crank
- 20hp 10% driveline loss
+ 7hp TopSpeed cat back exhaust (verified on dyno: Spec Boxster Build)
+ 5hp Removal of cat's (verified on dyno)
+ 5hp Under drive pulley (per other testing)
________
196 hp net at the rear wheels
Nice plug for the junk yard :-)
What is allowed in an engine rebuild? Can you custom make the rings?
What limits are there on the valve job.
IMS retrofit isn't going to get you anything.
Anything else would seem to be illegal.
What weight oil do you guys run?
Could you alter the cam to exhaust timing on the vario-cam by displacing a tooth and still not have interference but gain anything?
Note I don't race spec boxster -- but I've been involved in a few M96 rebuilds and its not hard to accidentally alter the vari-cam timing during install (but I've always caught it :-).
What is allowed in an engine rebuild? Can you custom make the rings?
What limits are there on the valve job.
IMS retrofit isn't going to get you anything.
Anything else would seem to be illegal.
What weight oil do you guys run?
Could you alter the cam to exhaust timing on the vario-cam by displacing a tooth and still not have interference but gain anything?
Note I don't race spec boxster -- but I've been involved in a few M96 rebuilds and its not hard to accidentally alter the vari-cam timing during install (but I've always caught it :-).
Mike
Yeah, some of the high mile motors run good after being loosened up!
There aren't very clear/good/complete rules when it comes to the rebuilds like you would find in Spec Miata or a class run by a more professional organization, unfortunately. So the term "stock spec" really covers most of your questions. At the least, we're trying to make sure everyone is using stock components.
We're supposed to be using stock Porsche pistons and rings. No aftermarket pistons/rings built to same size or anything like that. I have not seen limitations on valve jobs, other than the valves need to be stock.
Oil weight is up to the competitor/engine builder, there is no stock spec. I use 0w-50 Mobil 1 Racing oil.
You cannot legally alter the cam timing. However, I'm sure there are some that do. It is not something I've done or experimented with so I can't speak to the specific advantages.
__________________
4.0L Dry Sump Boxster GT race car - HRG #23
2005 Cayenne S - DD
There aren't very clear/good/complete rules when it comes to the rebuilds like you would find in Spec Miata or a class run by a more professional organization, unfortunately. So the term "stock spec" really covers most of your questions. At the least, we're trying to make sure everyone is using stock components.
We're supposed to be using stock Porsche pistons and rings. No aftermarket pistons/rings built to same size or anything like that. I have not seen limitations on valve jobs, other than the valves need to be stock.
It has come to my attention that my statement above has been cherry picked to support ones own personal thoughts and I just want to clarify...
A gentleman asked specifically about valve job rules and I replied above, that there are no specific rules in the rule book other than ''stock'', unfortunately. Some that wish to read into that assume that meant I would manipulate a valve job... that's not the case, just you hearing what you want to hear. It was a reply to a question specifically about valve job specifications.
As referenced just beforehand, a rule set like spec Miata actually has several pages about engine internal specifics, like posted below.
I did not say ''I have not seen limitations'' because I have exploited them, I said that because there are no posted values of limitations...
Short of buying new cylinder heads for every rebuild, there are modifications that need to be completed on any regular standard engine build. This is supposed to be cost controlled spec racing and engine rebuilding is part of it. There should be rules with values about plunge cutting and valve jobs and decking heads like any other reasonable spec but BSR is not at that level of precision, yet.
People will believe what they want... even with several independent dyno runs at several tracks back to back against other cars right out of qualifying. We know what the cars are running HP wise across the field because they have ramped up dyno testing and that is a big step forward.
It has come to my attention that my statement above has been cherry picked to support ones own personal thoughts and I just want to clarify...
A gentleman asked specifically about valve job rules and I replied above, that there are no specific rules in the rule book other than ''stock'', unfortunately. Some that wish to read into that assume that meant I would manipulate a valve job... that's not the case, just you hearing what you want to hear. It was a reply to a question specifically about valve job specifications.
As referenced just beforehand, a rule set like spec Miata actually has several pages about engine internal specifics, like posted below.
I did not say ''I have not seen limitations'' because I have exploited them, I said that because there are no posted values of limitations...
Short of buying new cylinder heads for every rebuild, there are modifications that need to be completed on any regular standard engine build. This is supposed to be cost controlled spec racing and engine rebuilding is part of it. There should be rules with values about plunge cutting and valve jobs and decking heads like any other reasonable spec but BSR is not at that level of precision, yet.
People will believe what they want... even with several independent dyno runs at several tracks back to back against other cars right out of qualifying. We know what the cars are running HP wise across the field because they have ramped up dyno testing and that is a big step forward.
Eric,
Never thought otherwise -- basically having a beer discussion over the net :-)
I'm building a pair of SP-1s, so arguably my question is mute to me. However I do track a Boxster S and I have either rebuilt or been a part of about a dozen rebuilds of these engines and I was trying to envision how the HPs could vary.
Note I'm a EE and shade tree mechanic hack not a professional engine builder -- so this is more of a thought exercise for me.
Yeah, some of the high mile motors run good after being loosened up!
There aren't very clear/good/complete rules when it comes to the rebuilds like you would find in Spec Miata or a class run by a more professional organization, unfortunately. So the term "stock spec" really covers most of your questions. At the least, we're trying to make sure everyone is using stock components.
We're supposed to be using stock Porsche pistons and rings. No aftermarket pistons/rings built to same size or anything like that. I have not seen limitations on valve jobs, other than the valves need to be stock.
Oil weight is up to the competitor/engine builder, there is no stock spec. I use 0w-50 Mobil 1 Racing oil.
You cannot legally alter the cam timing. However, I'm sure there are some that do. It is not something I've done or experimented with so I can't speak to the specific advantages.
I was reading up on the VarioCam -- as I understand it, the solenoid opens up from about 3K-5K, and is shut off above and below. If it wasn't working "properly", you would have different engine behavior. I'm not sure if that would be better or worse overall. I have to think there would be a tradeoff if it was to be engaged all the time as an example.
I was reading up on the VarioCam -- as I understand it, the solenoid opens up from about 3K-5K, and is shut off above and below. If it wasn't working "properly", you would have different engine behavior. I'm not sure if that would be better or worse overall. I have to think there would be a tradeoff if it was to be engaged all the time as an example.
Mike
Better to be working as designed, for sure. These solenoids and tensioners fail from time to time and there is an overall performance loss.
__________________
4.0L Dry Sump Boxster GT race car - HRG #23
2005 Cayenne S - DD
Couple laps in my stock (minus studs and gas pedal) from High Plains Raceway today. Still need to gain some confidence in the car and more in the driver Can't wait to be done with my build... you guys are having too much fun without me.
Let me start this post by saying that taking your car to the track can be a humbling experience. It is still one area where personal performance is easily measured and easily compared with others. And sometimes, whether you like it or not, the truth just stares back and gives you the middle finger.
Yesterday was one of those days for me.
Well, let's talk about the positive things first; the San Diego region PCA hosted an excellent event at Buttonwillow raceway with both racing and time trials on a beautiful 70F sunny day in middle of Central California farmland.
I also had to opportunity to meet fellow Forum member JayG and his son who were there for the time trial and I got a personal and upclose look at Topless' shiny white Cayman. That Cayman is a beautiful car!
Now, the reality check: I was S-L-O-W. As in 12 seconds off the pace in the first practice session. 12 seconds!!
I got better during the second practice session and took off 5 seconds. Then took another 5 seconds off in the third/qualifying session.
So I was only a few seconds behind the leaders pace right? Unfortunately, no. By the time that I caught up those 10 seconds, the leaders had taken 3 more seconds off of their times. And it wasn't just one or two drivers, 9 of the 13 cars in the Spec Boxster field were 3-5 seconds per lap faster than me!
During the race, I started well and kept up with the race pace (which is almost always slower than qualifying) until the halfway point when I started to fade rearwards. I think that I finished 12th or 13th. I say 12th or 13th because if I actually look it up, then I would know for sure and would have to say that I finished last. Ouch. That hurt.
To sum it up; I sucked and got my assed kicked.
The video should be pretty good since there was a lot of close racing in the first half of the race. I'll edit it quickly and get it posted.
P.S. I did not race today due to the rain that rolled in this morning.
__________________
1999 996 C2 - sold - bought back - sold for more
1997 Spec Boxster BSR #254
1979 911 SC
POC Licensed DE/TT Instructor
Good to see you out there Tom, sorry it wasn't a better day for you. We all have a few bad days at the track but the good ones keep sucking us back in. Racing ALWAYS beats sitting at home watching Oprah reruns.
Dan and I managed to have a pretty good weekend. We both posted personal best times as the track seemed to get faster all weekend. The Cayman works better at BW than Chuckie because there are more long straights so she can stretch her legs a bit. Still way too softly sprung so I have some work to do over this end of season break. Looking forward to 2016 with fresh tires, suspension, and weight loss.
__________________
2009 Cayman 2.9L PDK (with a few tweaks)
PCA-GPX Chief Driving Instructor-Ret.
Great meeting you finally as well. Sorry you had a bad day. I enjoyed watching all you guys with the running start. Real racing!
It was my first time at Buttonwillow. Its a challenging and fast with the long straights. Got into the low triple digits in 4th. Especially fun is the 4th to 2nd downshift at Star Mazda and then fast into the esses Sunset and the front straight. woohoo!
The rain came in the beginning of my 2nd session on Sunday. Got a good lap in and then started a bit of sliding in the corners as the rain started coming down faster. Brought it in, there is always another day...
All in all a great fun weekend.
__________________
2004 Boxster S 6 speed - DRL relay hack, Polaris AutoTop DIY
2004 996 Targa Tip
Instructor - San Diego region
2014 Porsche Performance Driving School
2020 BMW X3, 2013 Ram 1500, 2016 Cmax, 2004 F-150 "Big Red"
Currently, I am not using either of those. I do plan to install the TechnoSump (2 qt deep sump with horizontal tray) over Thanksgiving.
Thanks. If you don't mind, let me know how it goes. I've been evaluating the engine cooling options out there and have not been able to find a definitive answer ... probably user dependent
I've heard the S cooler only provides marginal cooling improvements
With an accusump type setup, I've heard that an oil leak will result in the entire system purging itself
External setups can be complicated and expensive, and cooler location can expose it to damage
Wish there was just an easy, straight-forward, proven solution
I can add a data point - in October I was at Roebling and my oil pressure was dropping in the sweepers. I added the LN Engineering 2 QT Deep Sump with X-51 baffle, and this past weekend at Road Atlanta my oil pressure did not drop. There are some possible "catches" however:
Catch 1 - I did not data log or have a camera - the oil pressure drops were "recorded" by the instructors riding with me watching the gauge at my request, and by me (foolishly) quickly peeking down during a steady state portion of a sweeper.
Catch 2 - RRR is my home track. While I am not in the fastest drivers there, it is the fastest for me and the car is cornering harder there for me.
Catch 3 - I have only ever been to Road Atlanta once before and that was 18 months ago. While RRR is pretty flat (as are all the other tracks I have gone to) and it is wide open with lots of runoff room, Road Atlanta has lots of elevation, and also lots of walls. 2 cars were heavily damaged when I was there last June, and this past weekend 2 more were heavily damaged (1 still drivable) and 2 others damaged but drivable due to a tailgating type collision. I bought the track insurance, and took it easy. And the corners are different. For me turn 1, 4, and 6 were the ones that I had my passenger watch the oil gauge on, and they reported no drops - the needle stayed steady at around 60'ish. Turn 4, a left hand sweeper before the esses is probably the one most like some of the turns at RRR.
The real test will be next time I go to RRR so it can be an apples to apples comparison, and maybe I can have a go pro setup to record the oil pressure gauge.
But I feel pretty confident that the issue is greatly mitigated. Also one difference was that the oil temp barely ever went above 200 F, where at RRR on my fastest laps it got over 200 but less than 220, maybe 215'ish? That may be due to the extra 2 quarts of oil I was running or that is was cold as $%^& this past weekend, water temp only ever briefly moved above the 180 hash mark.
I got a good deal on the LN Skid Plate so I put that on too. Probably not necessary since my car is not lowered. Charles N of LN engineering has an early Boxster with a 911 engine (so the engine is 1 inch lower) and he is lowered suspension too I believe. He said he ran without the plate for a while and was fine, but recently he went to pass a car on the highway and ran over some roadkill that lifted the whole back of the car up, and he said he was glad of the skid plate then. The front part mounts on the two lower bolts that hold the engine mount to the engine. The back part mounts on the two forward bolts of the diamond sheet metal brace. In my opinion this ties the engine to the rear frame and makes some interesting sounds. I kind of isolated it in the back with some rubber and fiber washers and I am trying to think up a solution to put some bushings or something back there, I can definitely tell the plate is on and while you don't hear or feel it at the track, at street speeds/noise there is some kind of unpleasant noises/rattling going on. Maybe the skis plate is rattling my rear trailing arms which are probably shot...
It took 11 quarts to fill it up the middle segment between the high and low mark on the dash gauge which is where I like to run it to avoid smoke bombs.
I am looking forward to reading more about Tom's install and experiences. I will say I love Reinzosil, it is 10,000,000,000 times easier than Loctite 5800 (or 5900 or whichever the one it is) to apply.
Steve
PS My oil temp sender is in the unused port on the driver side cover (where DOF oil feed would go), Chris Zang has a guide on here somewhere, and for oil pressure I replaced the oil pressure switch with a VDO oil pressure sender with warning terminal, not the Porsche part but the regular VDO part. I used part number VDO 360009 with an adapter (I should have gotten 360028 which had the right size with no adapter needed), and VDO 323055 oil temp sender.
Thanks for the contribution! I did forget to include the feedback on the deep sump pans being a risk, especially for folks that like to hop curbs, in an off situation where the ground is a bit uneven (we see that at a few of the tracks out here in CO).
Can't wait to be done with my build... you guys are having too much fun without me.
Lil Red
2009 Porsche Cayman 2.9L
Racing ALWAYS beats sitting at home watching Oprah reruns.
2002 Porsche Boxter S
2001 Porsche Boxster S
1999 Porsche Boxster
1999 Porsche Boxster
1999 Porsche Boxster
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1999 Porsche 996 C4
1972 Porsche 914
1984 Porsche 928S
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