in the most recent option magazine, there is a review of the Esprit 11.5 CR engine build up.

spec as far as i can tell:
11.5 CR pistons
Plenum spacer
Ti headers dia. 60 (tried 70 but lost torque)
Exhaust midpipe
Cams (think they are 272 but not mentioned in the artcile)
New Valve springs
ECU reflash (not mentioned - but safe to assume since they sell reprogrammed ECUs)

Total cost - including wages about $10K

interestingly they mentioned that they are working on a 4,320cc build-up, initially focused on the a stock bore build up to provide a cost effective NA solution

 

here is a quick and dirty attempt at looking at the tq curve by eye-balling the hp number on chart (i did convert ps to hp)

 

wow, look at that torque curve! The more I think about it, the more intriguing it is to do an all-motor build up... my next step is going to be Headers/Cams and then we'll go from there... 325 N/A HP with that much torque down low would be about the equivalent to a Stage 1 Stillen supercharger (without the ugly *** hood, of course)

 

This is interesting data. I assume you are saying this engine has titanium headers with 60mm collectors (2.36"), and that they tried 70mm collectors (2.75") but lost torque.

If true, this means that running 2.50" pipes from the cats to a 3.00" center pipe (Y pipe dimensions) on a stock or near stock engine would certainly hurt torque.

Do you know what diameter mid pipe was used?

 

Since this is an engine build-up, is that curve from an engine dyno, or a rear wheel dyno?

 

yes the article says they use titanium headers with 60mm collectors.. they sell a SUS and Ti version per their webpage

http://www.esprit.to/tuning_plan/fairladyZ33.html

don't know about the size of their mid-pipe.. buts more like a y-pipe and mid-pipe combined design..

 

not mentioned in the article but the stock figures look like a wheel horse power numbers in PS units.. so it would make sense for the build-up numbers to be on the same basis

 

I think this is true.. I have the JIC y-pipe on a basically stock engine and betting I've lost torque, certainly don't feel like I've gained it.. I'm not concerned, got it to complement a future build up of the engine, one way or another will be fully utilizing that 3" diameter

 

Would that even work on CA gas or even 93?

 

98 octane is what is mostly available here in Japan, this is on a different scale than in the US.. but i think it translates to about 94 or so octane on the US scale .. with proper tuning 11.5 should be possible (note the M3 and 911 run 11.5 and 11.3 CRs, respectively, on 91 octane)

 

wow......I really want to do an NA buildup the more I think about it.......

hey ether, if you don't mind me asking where'd you get those prodrive wheels and for how much? they look sick man!!

 

order them through autobacs here in Japan, got it as a package with tires so don't remember the specific price, but they are not an expensive wheel.. you should be able to get them through discount tire, they are a pro-drive dealer.. these just came out this year so might be hard to get

 

Theres no way that is correct. Those torque curves seem inflated. I don't see how you'll are making 200 lbs of torque at 2500 rpm stock.

 

whoops you are correct.. must be a typo in the equation probably used something like 5552 instead of 5252..