STL engine builds?

[coreyehcx]

Greg, you guys have it correct. FYI you can get oem heads from endyn from the pr3 cast non ITR.

I can touch on a couple of things.

The butterflies in the manifold were also on the h22 prelude vtec motor and is used for more torque in city/lower rpm driving and also supposed to improve fuel efficiency until vtakkkk.


The gsr head is not as bad as people make it out to be, the combustion chambers have been quenched so if you swapped a b16 head on your gsr you would have a decrease in compression stock for stock. The b16 head flows about 5 cfm better than the gsr so its not terribly different. The intake manifold stock for stock is the issue between the 2 in my opinion (b16a3 is the best under ITR).

FWIW

The one thing people don't realize is the intake side of the gsr head was designed to accept the inverted manifolds design. The runners need to be properly angled where they meet the head, AEBS actually was proven to make more power over the skunk/ITR style manifolds. I used this on my built gsr motor I had with a lot of success.

[Rabbit07]

Still hoping someone will clarify the 100hp/liter target.

WHP or Crank?
Examples of cars that fit this target with some math?

Thanks.

It's. Crank. What math do you want?

[tyler raatz]

It's. Crank. What math do you want?

Wow, that is pretty sweet! A Honda B18C1 only needs to pick up 10hp over 100% stock numbers to meet the class target!
Too bad a Mazda BP4W needs to pick up 40hp
Too bad this isn't designed to be a Honda only class, it would make a great one
Turning my STL Miata into a LP prod car just looks better by the minute

[Rabbit07]

What is the stock cam lift of the B18?

What we knew of the hondas is that they were all very close to the class limit. Ergo not much to gain from the cams.

Many of the other engines will gain in spades with the camshaft changes.

You also can't get too crazy with duration becaue compression is limited to 11:1. To much duration and you don't get any cylinder pressure.

[coreyehcx]

If you look at the discussion at the beginning of this thread we are discussing whp and not crank.

What am I missing?

If the 1 hp per 12 Lbs (195 for 1.8) is for crank output then I'm worrying over nothing.



Edit: B18 what?

Non Vtec B18B1 has a lot to gain from its stock compression and cam lift.


B18C1 cam lift oem is very close to the limit... I can add the specs in a few mins.

[Rabbit07]

If you look at the discussion at the beginning of this thread we are discussing whp and not crank.

What am I missing?

If the 1 hp per 12 Lbs (195 for 1.8) is for crank output then I'm worrying over nothing.



Edit: B18 what?

Non Vtec B18B1 has a lot to gain from its stock compression and cam lift.


B18C1 cam lift oem is very close to the limit... I can add the specs in a few mins.

I can tell you with a great amount of confidence that the expected Target is 100 HP per liter "crank" for STL and 120 for STU. And for those that care STO is the wild west ;-)

[tyler raatz]

So a b18c1 is only expected to make a gain of 6% crank over bone stock? What is the hp gain factor used for that engine in ITS? If 180 crank is really the number, someone has really screwed up.
THIS IS TOTAL BULLSHIT!!!!!

[Rabbit07]

So a b18c1 is only expected to make a gain of 6% crank over bone stock? What is the hp gain factor used for that engine in ITS? If 180 crank is really the number, someone has really screwed up.
THIS IS TOTAL BULLSHIT!!!!!

That seems a bit dramatic don't you think?

[bamfp]

If 180 at the crank is the target for the class then the GSR engine should not be allowed. I am getting 170+ at the wheels out of an ITS preped GSR engine.

[tyler raatz]

That seems a bit dramatic don't you think?

The more I stew over these power numbers the more rediculous your 180hp crank number seems. So no I dont think it was a bit dramatic. It is a Honda class plain and simple. I screwed up and built a car for a class it will NEVER be competitive in with the current rules and current rulers of the class. I will continue to race in STL up to the point that full built Hondas start to show up and are untouchable in a straight line.. At that point I will convert to production.

[tyler raatz]

If 180 at the crank is the target for the class then the GSR engine should not be allowed. I am getting 170+ at the wheels out of an ITS preped GSR engine.

Thank you!!!! my point exactly.

[bamfp]

I found all the parts to build a B16 to put in my 95 Civic. Now if I only had the $$$.

[Rabbit07]

The more I stew over these power numbers the more rediculous your 180hp crank number seems. So no I dont think it was a bit dramatic. It is a Honda class plain and simple. I screwed up and built a car for a class it will NEVER be competitive in with the current rules and current rulers of the class. I will continue to race in STL up to the point that full built Hondas start to show up and are untouchable in a straight line.. At that point I will convert to production.

Well since I am one of the "Rulers" I guess it is a bad idea for me to build a Miata for STL? Crap! I better sell that thing today and go buy a Honda.

The point is we have to start some where. Don't fret, cars must hit the track and start racing each other before any opinions can really be taken to heart. As a comittee the STAC will help to monitor the class through the use of SCCA Data boxes. So please race your car, continue to develop you package, and run some nationals where we might get a chance to pull some data. Most of what I have read on the forums since this class went national is mostly speculation and rhetoric.

[tyler raatz]

Well since I am one of the "Rulers" I guess it is a bad idea for me to build a Miata for STL? Crap! I better sell that thing today and go buy a Honda.

The point is we have to start some where. Don't fret, cars must hit the track and start racing each other before any opinions can really be taken to heart. As a comittee the STAC will help to monitor the class through the use of SCCA Data boxes. So please race your car, continue to develop you package, and run some nationals where we might get a chance to pull some data. Most of what I have read on the forums since this class went national is mostly speculation and rhetoric.

One of the other "rulers" has openly stated that no single car/engine adjustments would be made. If the 1.8 miata is too heavy, all 1.8 cars will get a weight break. If the 1.8 miata doesn't make enough power, all 1.8 cars will get an increase in power etc. Until spec lines are implemented and concessions are givin to individual cars based on actual needs, the playing field will be unlevel. The current rules just dont work, not only is Honda the highest potential power (by a large margin) it also gets to weigh less than the miata since it is FWD.

[Rabbit07]

As a side note one of my fellow STAC members has a GSR. He and I have talked at length about this. He is convinced he is going to get his ass handed to him by a Miata.

So you have the Miata guys complaining that the GSR is going to murder them, and the Honda guys say that we are going to have to do something about the Miata!!!!!!

Wait till I build a full tilt boogey 13b powered RX8?

[tyler raatz]

As a side note one of my fellow STAC members has a GSR. He and I have talked at length about this. He is convinced he is going to get his ass handed to him by a Miata.

So you have the Miata guys complaining that the GSR is going to murder them, and the Honda guys say that we are going to have to do something about the Miata!!!!!!

Wait till I build a full tilt boogey 13b powered RX8?

Has this fellow STAC member built an all out STL engine? light weight forged rods, custom lighweight pistons, special thin low tension rings, optimized valve springs, custom ground cams designed to work with the one best cylinder head and intake manifold found when flow testing several dozen, countless hours of dyno tuning, tuned exhaust and intake on said dyno? Or is he running a pretty much stock original honda engine with better valve springs and some off the shelf bolt on's?
If the later is true, he is gonna get his ass handed to him by a properly built well drivin Miata. If the former, the Miata will look like and ITC car in a GT1 race.

[tyler raatz]

BTW, bring on the RX8, under the current stupid rules for rotarys this will be even more of a pig than my Miata.

[Rabbit07]

From the ST rules;

"

Each class will have a baseline target power-to-weight ratio. Weights
may be adjusted or cars may be subject to changes in intake restrictors
to meet these targets. Cars may be required to carry data acquisition

equipment for review of performance. "

So with all this hard work on your BP, how much power are you making?

[Rabbit07]

BTW, bring on the RX8, under the current stupid rules for rotarys this will be even more of a pig than my Miata.

If the rules are so stupid, why did you build a car for the class? The core of the rules has not suddenly changed since it went national?

[tyler raatz]

If the rules are so stupid, why did you build a car for the class? The core of the rules has not suddenly changed since it went national?

I built the car knowing that when/if the class failed or just plain sucked, I could easily unbolt my 200-300 pounds of ballast, bolt on radial slicks and change the engine and go to EP or FP. It would not take alot of work to convert to prod, and I could sell my STL spec engines to someone else wiiling to try.
I am no longer going to post any power numbers seen or expected for my engines until convinced I am done and have found 100% of the available power. Once I have maxed out the package, my dyno numbers, build specs, tuning specifics etc will be available to anyone who wants them. I refuse to have anyone tell me my car is not competitive because I have not gotten 100% out of the engine.