High HP 914? Options

[d k]

Hello people.

I'm a noob here, but been around cars for awhile.

Recently acquired a 75 914 that is very clean and going to do the Subaru conversion. Car will be used mostly for track events and some odd miles on the street.

The question that I had, is how does this car respond to high horsepower? In stock form, the EJ257 will put out 300 at the crank and I'm wondering if it makes sense to tweak it a little more....

I've seen a few conversions done here and read through a ton of threads. Some very helpful info here, but I haven't read anybody's feedback on what the chassis will do if throw 500hp at it? Besides all the supporting mods necessary to handle the power, what will the driving dynamics be??
Maybe it's not worth to do anything except just the engine swap, but since it's going to get a full cage, big brakes and aero, maybe go big (IMG:style_emoticons/default/driving.gif)

David

[Randal]

I'd guess there isn't a whole bunch of money difference putting in a 3.6 (993) motor, along with a 915 as compared to a subi with 300hp.

And I'll bet there would be little if any performance difference, given the respective weights and all.

[pcar916]

I'd guess there isn't a whole bunch of money difference putting in a 3.6 (993) motor, along with a 915 as compared to a subi with 300hp.

And I'll bet there would be little if any performance difference, given the respective weights and all.

Don't know about the Suby torque, but the 993 works just fine with the 914 transaxle if it's properly built. And it's considerably lighter than the 915... and way cheaper. I have two 915's and one is ready to install, but the 914 transaxle simply won't break... unless I just want to do it for grins. Fortunately the 914 LSD will fit into my early 915 if I really want to install the thing. It's a spacer and shim adventure with the R&P at that point.

[Randal]

I'd guess there isn't a whole bunch of money difference putting in a 3.6 (993) motor, along with a 915 as compared to a subi with 300hp.

And I'll bet there would be little if any performance difference, given the respective weights and all.

Don't know about the Suby torque, but the 993 works just fine with the 914 transaxle if it's properly built. And it's considerably lighter than the 915... and way cheaper. I have two 915's and one is ready to install, but the 914 transaxle simply won't break... unless I just want to do it for grins. Fortunately the 914 LSD will fit into my early 915 if I really want to install the thing. It's a spacer and shim adventure with the R&P at that point.

993 have torque everywhere and there is zero maintenance. (IMG:style_emoticons/default/flag.gif)

Glad to hear about the 901 holding up. How about the CV's, did you change them?

Ha, my stock ones only lasted 3 events and I only have a little 2.4.

[pcar916]

Glad to hear about the 901 holding up. How about the CV's, did you change them?
Ha, my stock ones only lasted 3 events and I only have a little 2.4.

The 914 cv's worked fine with both street and track use and I replaced them once after 10 years. I ran stock cv's both with the 2.7 and the 3.6, then changed to turbo (108mm) cv's on 911 axles for a couple of years.

Last year I finally converted to 100mm 944 cv's with a modified 914 axle and 911SC stub axles and output flanges. Now they weigh many pounds less than the 108mm parts and I can get 944 cv's all day long. That's because the 911 axles are too short for our 914's, require big spacers at the cv, and the turbo cv's are massive. But if you are going to use the 108mm gear you can either do what I did, buy SwayAway axles, or modify original 914-6 axles exactly like the 914-4 axle mod.
(The 108mm cv's have 911 splines as do the 914-6 axles)

Regardless of which system you go with, the key to longevity in both transaxles and cv's (everything for that matter) is smoothness in your driving style. Shift like a banshee and your stuff will wear out or break sooner. Be chronically smooth and your running gear will last a very long time.

Point is if I was building from scratch and was on a budget I'd stay with the 914 stuff. But since there is a 5-lug conversion in the cards anyway I'd go with the 100mm cv's regardless. The axles in that case can be modified 914's or SwayAway.

[Randal]

Glad to hear about the 901 holding up. How about the CV's, did you change them?
Ha, my stock ones only lasted 3 events and I only have a little 2.4.

The 914 cv's worked fine with both street and track use and I replaced them once after 10 years. I ran stock cv's both with the 2.7 and the 3.6, then changed to turbo (108mm) cv's on 911 axles for a couple of years.

Last year I finally converted to 100mm 944 cv's with a modified 914 axle and 911SC stub axles and output flanges. Now they weigh many pounds less than the 108mm parts and I can get 944 cv's all day long. That's because the 911 axles are too short for our 914's, require big spacers at the cv, and the turbo cv's are massive. But if you are going to use the 108mm gear you can either do what I did, buy SwayAway axles, or modify original 914-6 axles exactly like the 914-4 axle mod.
(The 108mm cv's have 911 splines as do the 914-6 axles)

Regardless of which system you go with, the key to longevity in both transaxles and cv's (everything for that matter) is smoothness in your driving style. Shift like a banshee and your stuff will wear out or break sooner. Be chronically smooth and your running gear will last a very long time.

Point is if I was building from scratch and was on a budget I'd stay with the 914 stuff. But since there is a 5-lug conversion in the cards anyway I'd go with the 100mm cv's regardless. The axles in that case can be modified 914's or SwayAway.

I went with the 944 CV's as well. Clean installation and they handle the torque of my engine, at least so far they do.

Good point about being smooth. That is always my objective, but sometime it's easy to get agressive, especially in an autox venue.