Porsche-O-Phile

The header panel is supposedly different; I've been told it needs slightly more curvature to it in order to clear the intercooler. AFAIK the fenders are the same.

tifosiman

Fenders are definetly different. There is a sharp abrupt end in the front of the N/A fenders where they meet the end of the header panel and top outer corner of the bumper. The Turbo/S2 fenders are more rounded in that area. Really it's just a small amount of metal that needs to be trimmed to make a N/A fender into a Turbo/S fender.

The header panel is more rounded in the front, due to the intercooler on the Turbo and the Airbox on the S2. The headlight covers and plastic surrounds are different. Coolant overflow tank is different. The pic is missing the external oil cooler, and the rear metal pan. Boost guage. Keep going, there are others.............

Probably not. I'm telling you guys, the N/A trans can barely hold up to 143HP, let alone 50%-100% increase in that horsepower. Do yourself a favor and get at least an S2 or 951 trans, and roll that still-good N/A trans over for a little cash before it becomes scrap metal. And, why do you need to keep an N/A trans in order to use the N/A clutch and flywheel? Those are on the other end of the torque tube, and don't know what trans is at the other end. That makes no sense to me.

FYI the CV's on the 86 951 are the same as the 86 N/A.

You could baby the N/A trans all you want. But if it is worn at all, and there is any play in the R&P, the extra torque is going to kill it.

Porsche-O-Phile

I've still known people to shatter 951 CVs by pretending these are drag cars. . .

tifosiman

Yes, I agree with that! Usually it is people with some good mods putting down higher-than-stock 951 numbers. These certainly are not drag cars by anymeans, though.

Geo

Yeah, I hate it when people do that.

I guess the 951 only came with left side wheels and tires.

Of course it's possible to turbo the NA. The single biggest issue is engine management. Otherwise, the average ricer shop could probably do a better job than the factory did. For sure they would equip it with a better turbo (20 years of turbo development and all).

Geo

Yes and no.

For sure the final drive is a weak spot.

But, there are people running pretty sizeable hp increases w/o issues. A Milledge IT race engine puts out 185bhp and by the rules they MUST run a stock gearbox. You can replace the final drive, but a turbo final drive goes in the wrong direction, so nobody does that.

That said, if I were planning to turbo an NA, I'd figure a turbo gearbox into the plan for down the road if not at the time.

tifosiman

I agree with that. I guess I should have caveated my statement with the fact that I wouldn't use a used N/A trans for the turboing application, rather one that was rebuilt properly and tightly. It's the used ones that may have shim issues and r&p slop that would suffer quickly. Most N/A guys on a budget would really be better off getting a used S2 or 951 trans for a turbo swap, as it would be much cheaper than a properly rebuilt N/A trans.

tifosiman

The N/A trans was all they had at the time, there was no 951 or S2 trans out there. The 931 clamshell trans was stronger, but rare and pricey, and difficult to adapt to a 944.

Remember that the Callaway cars were new cars that were modded, so the N/A trans did not get a chance to be abused and worn prior to the application of an increased load.

As far as how they have held up, there are not many Callaway cars out there, especially with original owners that can verify that the original trans is still in them.

Geo

On the engine management front, I would be excited to see someone get a stand-alone utilizing a MAF from the get-go (instead of using the kluged together piggybacks) and then convert the injection from batch to sequential. That should be quite easily done. The plumbing is the easy part.

Geo

A MAF is superior to a MAP sensor. The MAP is highly VE sensitive while the MAF if highly VE insensitive. With a proper maps in the ECU you can make pretty big changes to air flow and not have to reprogram the ECU. Everytime you change the air flow with a MAP you pretty much have to reprogram because the air mass calculations will be off resulting in poor A/F ratios.

jp944

Gauge cluster too, but that's splitting hairs.

Fishey

The Master Cylinder of the cars are diffrent (I don't know about the booster)

theedge

And the engine wiring harness, vacuum lines, injectors, fuel regulator?... Its a long list.