michaelmount123

Found impressive power in a lightly modified S2 engine for a mid-western autocrosser using the stock intake manifold and stock throttle body. The lower end uses a stock crank, 951 rods (with the Rod Mod), custom 12:1 C/R pistons, and dry sump. Heads are only mildly worked and the cams are a custom hydraulic grind for this configuration. A fully configurable ECU is also used rather than the Motronic. Dyno is a Dynapack which is often considered very conservative. Note that RWHP is shown.

fred27

Well done and thank you for sharing.

Eric_Oz_S2

Michael

That's pretty impressive power - about the same I make with my 6psi supercharged s2. How streetable is that engine?

It seems like most of the power gain is probably attributed to the cams. I presume the exhaust is a little freer as well with no cat?

culture

BINGO! thats what i want to see! thanks for sharing and keeping hope alive!

"rod mod"??

michaelmount123

[QUOTE=culture;12570325
"rod mod"??[/QUOTE]

https://rennlist.com/forums/944-turb...aring-fix.html

AlphaOmegaPower

I'm liking what our 16v can do

culture

thanks for the link.

understanding that this motor was purpose built, autocross in particular, how much of this tuning meaning fueling and cams are possible for a street engine? its using stock intake and throttle body, but what about exhaust? headers are doable for the street, but if it needs an open exhaust that would be excessive. are these type of numbers just out of reach for the mototronic?

if this motor could be dropped into a daily driven S2 and not have to be on boil or revved to death to enjoy that bump in power, i bet a lot of people would be happy. i'd def be one of them.

michaelmount123

This engine is tractable, but being streetable is questionable, given that your's is a daily driver. You'd probably want to pull it back a bit. If you lowered the compression slightly for pump fuel, and tamed the cam profiles somewhat, you would have better traffic manners but retain the on-ramp rush you're looking for.

Motronic would work if you have access to someone with the tuning capability. That's a big IF since few shops can really alter the fuel and timing maps. Behe Performance in MD can do it if you really want to pursue it.

The engine charted has special large tube stainless headers and a large exhaust but does run through a low restriction muffler. The headwork is key and would need to be duplicated. All the mods should be on top of a fresh lower end, particularly the bores since most S2's are high mileage and no longer round and square. This engine is dry sleeved with custom JE pistons and a custom ring set.

culture

thank you sir…and absolutely noted.

i find it interesting that this was possible without even moving to 3.1 or 3.2 litres (offset crank). i was thinking that was absolutely necessary, but i guess not. I'm becoming more and more of a believer in the 16v n/a possibilities and i think i'll be sticking with the n/a route when i pull my motor for the refresh.

thanks again for the info

sm

I'm going to ask the question: what's the conservative cost estimate to dial the mods back and make the engine appropriate for a daily driver? Will dry sump be necessary?

Thanks

michaelmount123

A dry sump is not necessary. Further, I see no reason for it on a street car.

Regarding cost of this engine, it is probably something you can figure out. The challenge is finding someone to do it that's capable. It's not rocket science, but it gets woefully expensive to do it twice!

EliteThink

wow, great results, more confirmation in staying NA. Some out there are building 400hp NA motors. thanks.

Aivar88

400hp na ? Any links?

EliteThink

i cannot recall the guy's name, but there is a guy on the east coast building them, i think broadfoot is right about there too.

AlphaOmegaPower

Why not ask the guy who started the thread about the 400hp engines.....just a thought...