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I am planning to run Scrap Metal in DMod (Autocross) currently the only thing keeping me in the big boy class is the fact that I have the F22C (2.2 Liter engine). My understanding is that the blocks from the S2000 are all the same. They increased the displacement by changing the crank, connecting rods and pistons to increase the stroke and give the larger displacement of 2.2. The increased displacement gave the engine about 6% more torque. The 2.0 displacement would make Scrap Metal DMod legal and allow me to make it much ligher

I am testing the water to see if anyone would like to swap their F20C Crank, connecting rods and pistons for mine. Preferable someone who does not have a running car so you could ship me your parts and I would return mine after a couple of weeks. If you were fairly local I could just pick up the engine and do the swap on both. If your interested let me know.

As always I am always open to suggestions and also keeping an eye open for a good deal on an AP1 engine with transmission as I plan to rebuild the chassis soon am may just end up with 2 cars.

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2015 & 2016 EMod Florida State Autocross Champion
2013 & 2014 DSP Florida State Autocross Champion

Scrap Metal Build Log viewtopic.php?f=35&t=14558

The cam & springs are also different. The "hot" set up seems to be AP1 cams/springs/transmission on the AP2 engine along with a way to spin it up to 8,750.

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mobilito ergo sum
I drive therefore I am

I can explain it to you,
but I can't understand it for you.

I know I am sort of doing it the wrong way but the class determine the need. Once I have the shorter stroke I will up the rev limit which will give me me about the perfect speed for 2nd gear. I have a 3.72 rear end and 25.5" tall rear tires. At 8,900 rpm ( a little higher than normal for nationals) I hit 70 mph. With the AP1 stroke I would go to about 9,500 rpm giving me 75mph top speed which should be perfect. The AP1 transmission would give me 2.5-3mph extra.

At Nationals I just touched the limiter as I crossed the line at 70mph. Mind you the stalker hit 83mph in 3rd so I clearly need more power. I would love to find an AP1 engine and transmission at a good price so I can have spares and options with the transmission. The big issue I have is my AP2 engine only has about 40K miles on it and make amazing power and works perfectly. Its hard to take out a great transmission like that and put in one with 80K+

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2015 & 2016 EMod Florida State Autocross Champion
2013 & 2014 DSP Florida State Autocross Champion

Scrap Metal Build Log viewtopic.php?f=35&t=14558

No Japanese take outs?

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Honey anyone?

But you still need the cam & springs to make power at the higher revs.

_________________
mobilito ergo sum
I drive therefore I am

I can explain it to you,
but I can't understand it for you.

I would have to see a dyno graph to see the difference. My car is just an autocross car that only runs in 2nd gear after the launch. Average autocross speeds are 30-70mph most of which is in the 40-60 range. Not sure what difference the cams would make and if the juice is worth the squeeze. I would give up a little power for reliability any day. I doubt changing the AP2 to and AP1 would give me more than 10WHP anywhere and I doubt there would be any net gain across the range.

Here is my dyno graph.

While the power would continue to drop off all I really need at the top is more speed not a huge amount of power. I heard the Brian Crower stage 2 cams have some good gains so that may be an option too.

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2015 & 2016 EMod Florida State Autocross Champion
2013 & 2014 DSP Florida State Autocross Champion

Scrap Metal Build Log viewtopic.php?f=35&t=14558

You're looking for the most area under the HP curve for the RPM's you're using. In addition to your graph you should also be getting the tables of numbers from your engine guy. Add up all the numbers for the RPM's your using and use that answer. Whatever the aqua colored trace is above that hole in the power band at 4K would be a terrible thing to have.

When they run your motor, the speed the dyno sweeps thru the RPM's affects how accurate your numbers will be - it smooths out the graph when it is done more slowly. A dyno shop may want a lumpy graph because after a couple of runs they'll find one with a little extra peak and they'll take credit for it - but it's just a number with a little extra error in it. It's hard to find really honest dyno places because they really don't get rewarded for that.

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

Why not just buy a whole engine, test them back to back, and sell the one you don't want?

Mixing and matching worn engine parts is kind of going against your goal.

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-Andrew
Build Log
Youtube

The different graph lines were testing the VTec engagement points. The aqua was at about 5K which is under stock which is closer to 6K. You can see I gained a lot of power by dropping the VTec down. I think it is set to right around 3K. My dyno guy is great, the files are all completely unlocked and I have full access to everything. I actually build the tune myself and got the car running fairly well. He then dialed it in for me on the dyno.

I think buying a 2nd engine is a good idea and will keep my eye on craigslist as they show up from time to time. My understanding is an engine with similar mods to mine should only make around 220-230whp and 160-170tq so I am reluctant to use a different motor. If I were to buy the F20C though I could definitely compare and event spend a day at the dyno shop swapping parts out and testing the numbers.

I think some of the gains are from the short exhaust and lighter drivetrain so a different engine would also have that advantage.

_________________
2015 & 2016 EMod Florida State Autocross Champion
2013 & 2014 DSP Florida State Autocross Champion

Scrap Metal Build Log viewtopic.php?f=35&t=14558

Wow, that was worth it!

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

I was very happy with the gains. The dark blue line is at 3K8, the general recommended setting from the S2000 community is 4K, even at that I was giving up 15+Tq. Glad I compared the numbers on the dyno. I basically run entirely on the high cam as it's typically never under 3,000rpm one a run starts.

_________________
2015 & 2016 EMod Florida State Autocross Champion
2013 & 2014 DSP Florida State Autocross Champion

Scrap Metal Build Log viewtopic.php?f=35&t=14558

[quote="wrightcomputing" I have a 3.72 rear end and 25.5" tall rear tires. [/quote]


This statement just hit me. I have the 2.2 but I was going to run the Miata 3.9 diff (I have Miata spindles too). In the real S2000 the 4.10 rear on the 2.0 engine is a little tough to launch without massive revs which creates issues with the clutch so I was worried the 3.9s might be pushing it, but I too wanted more speed in 2nd for autocross.

Everyone I've seen has run the 4.10 in their Locosts. Have you actually seen anyone run the 3.72 and how was it off the line? That would definitely get the speed I need in 2nd. I'm not sure that's available in anything that just slots into the Miata diff and I sure want to keep it to make things easier in the axle department.

_________________
mobilito ergo sum
I drive therefore I am

I can explain it to you,
but I can't understand it for you.

That launch in my car is incredible, the power to weight is huge so the taller gear does not matter. I launch in 1st gear at low RPM otherwise it the tires spin for a slower launch. Remember your locost will weigh about half that of the original S2000 so you effectively have double the power.

My LSD is the clutch type 1.5 Way, 3.72 final drive from the 1989 Toyota Supra Turbo. I have also looked into a taller final drive but 3.56 is the only option and its a lot of work to gain about 3mph. Increasing to 25.5" tall rear tires gave me about the same gain but also increased the contact patch. Top speed is 70mph in 2nd, If I get the AP1 engine/RPM I can get that up to 74/75.

_________________
2015 & 2016 EMod Florida State Autocross Champion
2013 & 2014 DSP Florida State Autocross Champion

Scrap Metal Build Log viewtopic.php?f=35&t=14558