US vs ROW 3.2
 

Differences,
What parts needed to get the missing HP? I have the Steve Wong chip, Fabspeed bypass tube and Cup modified airbox cover, what else besides a 3.6/3.8 swap?
Eric

Compression ratio

How much HP is the US version giving up to the Euro version?

It's not what parts are needed, it's what parts aren't needed. Remove anything emissions rated. Advance your timing a few degrees. Then use DIN HP instead of SAE net HP. US HP specs were gauged using SAE, Euro ratings used DIN HP which is a difference of 1.4%.

The compression ratio for the US is much better for longevity and engine health given the fact that gas formulas have changed. And little if anything will be gained with euro or higher compression pistons.

Reference: up-fixen der porsche, volume 11, page 20, Alan Caldwell

I've run my '84 US car on a dyno back to back with a '84 RoW car... with a factory chip, cat, and heat exchangers, the RoW made 199 and mine made 194.
With just a cat bypass and SW chip, the RoW car made 220, whereas with headers and SW chip mine could only crank out 214.

So the difference is significant.

Cuuting the airbox cover not means HP gain but loss............tested on a dyno , same day , same temp'.


(3.2 tested)


No others mods on it.

84-86
 

US: 207 bhp (154 kW; 210 PS) (@ 5900 rpm)

ROW: 231 bhp (172 kW; 234 PS) (@ 5900 rpm)

I have somewhat of a hybrid engine as it is a US-spec 3.2 with Euro 10.3:1 P&Cs. Also running SSIs and a Steve Wong chip. I have an issue with my wide-open throttle switch causing me to run rich at full throttle, but it still made 201 rwhp on the dyno. FWIW, I have no issues running 93 octane.

A possibility is that there could be a 3% HP difference because of residual drive train drag, difference of the two cars.

I do not question that difference is significant in your experience, but I also don't don't assume it is that way across the board. The same could be said for the difference between any two engines, US or Euro. The HP published specs by PORSCHE are conservative were the minimum that one could expect with a new engine. Likely actual numbers for many engines were higher.

I believe the major difference was simply in tuning for emissions, the rest of it is a myth that has been propagated by ROW owners for bragging rights and ROW sellers to squeeze a little bit more out on resale, and buyers for justifying their purchase.

Also, weren't there several versions of RoW engines produced depending on where they were going? IE Asia, Europe, etc.

Yes there were different ROW models (some not as powerful as others) but your comments are way off otherwise.

Lets talk Euro ROW: I have a German ROW and US 3.2 both 84 models. The ROW is much much quicker. In a roll on test the ROW pulls way ahead every time. When I say way ahead I mean 3 or 4 car lengths by mid 3rd gear.

The 3.2 ROW has a higher CR, much better gearing and is significantly lighter stock. Its not conjecture but fact (from Porsche) that the ROW is more powerful and faster.

As for your comments on pricing it would take significant cash to get a stock US model to the same power as a ROW and it still wouldn't be as light, nor have benefits such as a trans oil cooler and better gearing. All things being equal a ROW is clearly a more desirable car and thats why they carry a premium. Same as a most other collectible cars where people value the US model less. A lot of folks on here would be better served buying a decent stock Euro than messing with a US to get more performance.

To the OP's point even if he could get the same horsepower (doubtful without opening up the engine new pistons) the ROW would still be faster due to the weight and gearing.

Some cars are just faster than others, you could take one car that rolled of the line, and compare it to the one that rolled off the same line before it and get the same results.

Roughly 10 lbs equals 1 HP, how much of a difference in weight is there between a US spec car and a ROW?

... Again, not sure what significant cash means to you but what do you think would need to be changed in the US version to meet the HP of a ROW version? I think a performance exhaust and a chip, with some tuning would do it.

Not sure about the 3.2 but my '83 930-10 ROW that replaced my US '83 930-16 had more differences than emissions.
The compression is 9.8-1 rather than 9.3-1. The intake runners are a larger diameter and the fuel head and CIS are different to deliver more fuel (not interchangeable with US CIS).
All of the ROW's were nikasil too not that that added HP.
The redline is 6800 rather than 6200. Rated 204 hp and 196 ftlbs T vs. 180 hp/180 lbft T.
I can feel the difference in the same car the engine was swapped into.

This is a good reference to the discussion.

Difference in compression on an US and an Europe car? - Rennlist Discussion Forums

Having had a non catalyst euro 231 hp and a catalyst US 217 hp 87 Carrera I can confirm that the euro car is (feels) much stronger and faster than the US counterpart.

Agreed.

I think the weight difference is 115lbs in total.

Honestly I don't think a pipe and chip will do it (maybe within 5hp) and you could do the same to a ROW and it would still be 24hp ahead (1984-86) like for like plus have better gearing. Notice that SW also does chips for ROW cars.

When I say significant I mean 10k or so to open the engine and up the CR with new pistons. If you are going to do that then go 3.4.

Agreed, loose the weight and go 3.4.

Yes, if its not bone stock, then you might as well go ahead and just build it for performance. Chasing a few points of CR so you can say you have upgraded it to ROW specs isnt worth it.

There was an interesting point made in the rennlist discussion, that the differnce in Piston Heights was 1.3mm. The EURO engine must use the thicker base gaskets (0.50) as well to gain the clearance between the piston and the head, so this would add a tiny bit of displacement overall. So even if one was simply shaving the heads to gain compression on the US engine, they wouldnt gain much, the only way to get more out of it from the inside is displacement and cams.