STL engine builds?

[coreyehcx]

I was curious if anyone has completed an actual STL vehicle specifically built for the class?

I'm finishing up my own and I'm curious to see what type of power some of these engines will be making. I hope to dyno mine at some point in the next few months (b18b/civic) ans was looking for something to compare to.

Thanks

[Greg Amy]

I don't think there's any 10/10ths builds out there yet. But when/if STL goes National the floodgates will open!

I think our target (I'll have to check) for whp/wt is right around 12, so if you're around there you're in the ballpark (and don't hold me to that number as a hard fact). Generally speaking, the larger-displacement cars will not be able to take advantage of the cam lift and compression ratio rules as much as the smaller ones can, so that should help a lot. - GA

[TStiles]

Here's some insight in regard to where the miata guys think they will come in :

http://mazdaracers.com/topic/201-miata-stl-builds/

[coreyehcx]

I think our target (I'll have to check) for whp/wt is right around 12, so if you're around there you're in the ballpark (and don't hold me to that number as a hard fact). Generally speaking, the larger-displacement cars will not be able to take advantage of the cam lift and compression ratio rules as much as the smaller ones can, so that should help a lot. - GA

Greg, I'm just trying to get an accurate take on this.

Above, earlier in the discussion you listed an "estimate" of Whp which is different obviously than Crank.

Rabbit07 is adamant this "estimate" is crank?

I'm just trying to see which is correct.

[Greg Amy]

Forget all the discussion about targets, ratios, horsepower, crank, wheel, whatever. It's all a fantasy.

There are zero (none, nothing, nada) documented hard or soft limits/targets for any of that. Here's what's documented, right at the beginning of the Super Touring Category Specifiations:

Super Touring Light (STL) is a small-bore “tuner” class with engine
displacements of 2.0 liters and under. STL encompasses a lower level
of allowed modifications compared to STU and STO.

And later in the regulations:

Alternate engines may be used, if the manufacturer of the vehicle
and engine are the same (e.g., an Acura engine installed into a
Honda car) and was available in a car delivered in North America.

And, later in the STL regs:

The engines from the following cars are ineligible for STL:
Honda S2000, Acura Type R

Turbocharged engines are not permitted in STL.

...from which one can quickly infer that the 190hp (of the ITR) and more is not "acceptable", and stuff smaller than that is "acceptable."

That's it. Nothing more. That's all there is, laid out in black and white (well, red and white in the 2011 version). There's nothing in the CRB's or the STAC's "special super secret backdoor deals rulesbook"* about any kind of ratio guidelines. Anything else is either a fantasy or someone else's internal guidelines on what they think should be in the class. Or, maybe they're just inferring from existing information, just like you are.

You guys are getting your panties all in a twaddle about the existence of some secret backdoor deals going down; I can understand that, given my long-term history of this org. However, everything you need to know about this class is right there, downloadable in all it's glory in PDF format.

Read it, then you can choose to participate or not.

Your call.

GA


* That's a joke. There really isn't a "special super secret backdoor deals rulesbook. It's actually a "double super-secret backdoor deals rulesbook". It could be in there, I suppose, but I haven't seen that one since I'm not part of The Inner Circle...yet...bwuhuhuhuhuh...

[mossaidis]

Forget all the discussion about targets, ratios, horsepower, crank, wheel, whatever. It's all a fantasy.

There are zero (none, nothing, nada) documented hard or soft limits/targets for any of that. Here's what's documented, right at the beginning of the Super Touring Category Specifiations:

Super Touring Light (STL) is a small-bore “tuner” class with engine
displacements of 2.0 liters and under. STL encompasses a lower level
of allowed modifications compared to STU and STO.

And later in the regulations:

Alternate engines may be used, if the manufacturer of the vehicle
and engine are the same (e.g., an Acura engine installed into a
Honda car) and was available in a car delivered in North America.

And, later in the STL regs:

The engines from the following cars are ineligible for STL:
Honda S2000, Acura Type R

Turbocharged engines are not permitted in STL.

...from which one can quickly infer that the 190hp (of the ITR) and more is not "acceptable", and stuff smaller than that is "acceptable."

That's it. Nothing more. That's all there is, laid out in black and white (well, red and white in the 2011 version). There's nothing in the CRB's or the STAC's "special super secret backdoor deals rulesbook"* about any kind of ratio guidelines. Anything else is either a fantasy or someone else's internal guidelines on what they think should be in the class. Or, maybe they're just inferring from existing information, just like you are.

You guys are getting your panties all in a twaddle about the existence of some secret backdoor deals going down; I can understand that, given my long-term history of this org. However, everything you need to know about this class is right there, downloadable in all it's glory in PDF format.

Read it, then you can choose to participate or not.

Your call.

GA

It's quote-worthy, except for the last part.

[Andy Bettencourt]

Describe STL: ITA weights, ITS power, and ITR speeds.

Principle is cool.

Chris, just because Greg thinks the Miata will compete doesn't mean jack-squat. Any theory is predicated on expected hp levels. The target HP Tyler is hoping for is WAY beyond anything that the interweb has produced and I wish him luck. The Honda's are much better known. In order to be in the ballpark, the Miata is going to have to find (goal being 180whp) EIGHTY crank hp from stock with the cam and compression bumps.

Like I said before, even if the 1.8BP motor from Mazda can make decent gains and in a good chassis it can compete, it's only a two horse race.

Edit: AND - if you and Greg run around and play nice together on-track, I won't so much care, I would need to see the numbers. Right now, Greg is still in development and is running ITS times so it's really impossible to see any data until we compare the stat sheets.

Edit-Edit: I believe enough in the LAP SIM stuff to suggest that at these power levels, there should be a 5% difference in FWD-RWD given the same front suspension design.

Math example:

GSR 1.8 into a HondAcura with double wishbone fronts: 185whp. THAT is the target everyone is looking at when deciding to build. In order to hit that number, what will a RWD 1.8-based car have to make for power to be on par? How about the 1.6's? Let's do some math.

[mossaidis]

Mickey wondering if STL is some deep seeded urge and "secret" way to get other manufacturers other than Honda and *maybe* Miata to produce small displacement, higher hp, freer breathering engines in the US. hmmm...

Also, remember that rods, vales, valve springs, flywheel/clutch are free too.

[Z3_GoCar]

Edit-Edit: I believe enough in the LAP SIM stuff to suggest that at these power levels, there should be a 5% difference in FWD-RWD given the same front suspension design.

Math example:

GSR 1.8 into a HondAcura with double wishbone fronts: 185whp. THAT is the target everyone is looking at when deciding to build. In order to hit that number, what will a RWD 1.8-based car have to make for power to be on par? How about the 1.6's? Let's do some math.

Easy, 5% of 185 is 9.25 -> so let's just round it to 10hp -> so any 1.8 liter rear wheel drive platform will have to make 175hp at the wheel.

[JeffYoung]

This one still gets my goat.

WHY?

When we were looking at Lapsim, I discovered that the only "input" into the program for "FWD" was checking a box that said that. I sent an e-mail to the company that makes the program and asked them to explain what this changed in the program. No response. No one on the ITAC was ever able to explain how Lapsim modelled the FWD "deficit," what factors it used, etc. It just spit out differing lap times with no explanation.

You want to talk about black box car classing/weighting, that's about as black and box as it gets....lol....

.

Edit-Edit: I believe enough in the LAP SIM stuff to suggest that at these power levels, there should be a 5% difference in FWD-RWD given the same front suspension design.

[Mrsideways]

The car I want to build on paper says about 200-210whp and 2340lbs mid engine. But I have a STU car so it's just bench racing.

[coreyehcx]

Thanks Greg,

I'm not holding you to anything because I know its changing all the time.

By my calculations which could be wrong, would put me at ~195 whp which would seem to be pretty difficult within the rules for my specific motor(my choice to use it I know).

2340/195 = 1 HP to 12 LBs

I have seen a lot of non VTEC 1.8 B18 motor dynos and build outs and that seems like a difficult number to hit with a 10/10ths build.

I'm assuming my current build is probably around a 160ish whp. I guess 190 is possible and I wont know until I dyno my own build which is probably a 6 or 7/10ths build.


Thanks guys for the additional posts I just saw. I'm just trying to see where people might be at to see if I need to go the distance on the few things I skimped out on. I'm new to club racing and look forward to it all in 2012.

The things I didn't have done were gasket matching, overbore, blueprint and balance, and left a little on the table in terms of lift @ .423, .413.

This is a dynojet from an almost identical build as mine except I have a better header, compression ratio is 9.2:1 and mine should be right at 11.0:1 limit.




I'm just looking for help/knowledge, I'm not trying to start a debate or an argument about engine allowances or anything.

Thanks again.

[Greg Amy]

What B18 engine are you building? Maybe the Integra B18A1/A2 from the Integra? That dyno chart shows "B18A", which is a Japan-only engine, not really related to the US-market B18s...The Integra B18s are reportedly hitting high 130s whp in IT trim, and that's before the cams and compression allowed in ST...they've left almost another point-and-a-half compression, and a good bit of lift and duration, on the table.

I'm running the B18C1 (Integra GSR engine) and I'm hoping to hit that 195hp number; any twin-cam head should get pretty close.

[coreyehcx]

B18B1, I tested it for the first time at Roebling this past weekend so its finished for the most part. I'm assuming that's what they tested (B18A1) and if not the differences between motors are .2 in compression between USDM/JDM. Those motors are identical outside of that so they are related just like a JDM B18C-non R and a USDM B18C1.

I need to try to find these IT B18A/B1 specs to see how they are making the power and go from there. I looked at the Ruck ITA integra end it says 150 hp I just dont want to assume whp.

Going from 130ish to 195 is a pretty big jump from cams and a point and a half of compression. I can see it happening with a ported head on the B18B1 since the airflow for that head is pretty dismal.

I wouldn't imagine you plan on discussing how you plan to hit those numbers with the B18C1?

[Greg Amy]

Ah, but head porting is not allowed in ST Light...

The B18C1 is reportedly making 175-ish whp in ITS trim, and it has another half-point of compression and some cam tuning to go (but not much in the intake lift; that's already at .423"). The nice thing about when we ran that engine in ITS was that I noticed the thing would pull all the way up to redline, and feel like it wanted to go more. So we'll throw valve springs and retainers to take advantage of that, do the overbore, add some compression, do some cam tuning on duration (and add lift on the exhaust), use adjustable cam gears, windage the bottom end, and stick the intake some place where it's very, very cool...tune the Hondata to sweeten the pot and couple it to Type R gears and a numerically-high final drive I think we can get there.

All it takes is time and money, right...?

GA

[shwah]

I'm running the B18C1 (Integra GSR engine) and I'm hoping to hit that 195hp number; any twin-cam head should get pretty close.

No VW group motor will. Not without porting, or allowing non US market NA 20v motors.

[Chip42]

"L/LU" suffix (mid 80's to early/mid 90's era) toyotas won't either. but the non USDM ship has sailed, apparently.

Corey, we've talked offline, but I think there's a lot of small change you can pull together on that B18B, and if you decide to go balls out on it that small stuff would add up to a pretty good gain. likely not as much as a good header over a crap one, but gains. and there's the real consideration that most "known gains" are from all out drag / drift type unrestricted builds or some kid with a new cam, a blowmolded case of sockets and a camera who swears up and down that he's only seeing 3hp, yo. either way, the formulae we deal with in IT and ST are restrictive in ways that traditional engine builder logic is still seemingly oblivious to. doesn't make the knowledge wrong, but it doesn't make it right, either.

your car runs well, and there's a lot left in the package - from the loose nut to the tires. develop that and build in iterations.