So I thought I would finally do a write up on some of the mods that I read about people on hear asking about. One thing to remember about any modifications to any vehicle is they have to be supporting ones. You can't just buy shiny things throw it on and hope it works. At the end of the post I will list all the current mods on my car. I did the following mods in this order to my car.

Mod: FrWilks Race Chip
For the $125 I spent on it, it was well worth it. This was one of the first upgrades I did and I noticed the top end felt better along with less lag or herkery jerky on the low end. The downside was that because this doesn't use the o2 sensor my fuel mileage never got better than 26 mpg when I was using the chip. Gave the car a different exhaust note and sounded more aggressive. It also only took all of 20 minutes to install.

Mod: Cat Delete
This ended up being by accident since my cat had broken at the weld so I decided to put a straight pipe on the car. This made the car rev faster in combination with the FrWilks chip. I did not feel a loss of power in the low end like I heard others say. When I switched the chip back to stock (curiosity) I was able to then tell the loss of tq in the low end.

Mod: Bursch Header
I have read some positive and some negative things about his header. Most people will say to not even bother. When I got this I had the test pipe be fitted with an SLP hollow pipe. This made the car feel fast (no dyno results) What I mean is the car just felt like it could keep on revving and did have that feel of power dropping in the top end. Down low felt strong (since the primary pipes are 24 inches long, yes I measured) which makes great tuning for the 3,000 to 4,000 rpm (numerous research I have done on exhaust tuning) I also liked the 4-2-1 design as if done right will gain a better power increase over the entire rev range. My goals for the car are for it to have most of its power down low hence why I decided against a 4-1 header. Also the tube size was a little big if I were to leave it where it was but I knew I was going to increase the airflow soon. So I decided it was okay for what I was doing. (again the perfect thing to do would be to get a custom designed header to the tune of your engine.)

Lastly quality: The header cracked on the test pipe flange and I ended up having it completely welded together. The only way to remove my exhaust is to cut it off now.

Mod: Spin Tech muffler
Horsepower gains probably none. Sound quality... Really awesome when in conjunction with the SLP pipe. I really love tunnels because you can hear the exotic tone of the car. While in the car and driving it isn't obnoxiously loud but just right to hear and then when you step on it you can't help but grin!

Mod: Na-Tune
Installing was nice and easy. First thing I noticed when I turned the car on was the sound. It no longer sounded like the car was straining. And when you drive it, it feels so much stronger and free. Comparing it to stock their is a huge increase in response everywhere! and Gas Mileage has gone up! Now the tricky part comparing it to the FrWilks Chip

Na-Tune vs FrWilks Chip
I do not have dyno numbers, I do have stop watch times and my impression. Lets start again with the FrWilks. The FrWilks feels very fast at the top end. My impression of this is because it probably peaks towards the upper rpms with the other mods on the car. It has good response down low but you still have to rev it up to feel the increase in power. The Na-tune has power and response everywhere. When it comes to daily driving I find 3rd gear to be my favorite around 2k rpm to just tap my foot down and off I go. The car just erupts in the low and mid rpm. Now that is not to say in the upper rpm it dies off because their is still a noticeable increase in power there. But it doesn't feel "as strong as the FrWilks" Now let me explain this "feeling" some more. I believe the FrWilks "Feels" stronger or faster because it is peaky for the power curve. Whereas the Na-tune is a broader power range bring the power up everywhere on the power curve. So the car may not "feel" faster up high but it IS faster in that area as well. I remember a saying from a drag strip racer I met as a kid, "If you want to feel fast get something that has a shape of a mountain peak for the power curve, if you want to be fast get something that has a flat plateau." And that is what I believe the Na-Tune does for the 944 as Joshua's Dyno's have proven as well. Keep in mind this is without the install of the woodruf key for the cam. Which I am eager to install in the next coming weeks.


List of Mods:

Fidanzza Flywheel, Centerforce Clutch, A/C Delete, PS Delete, LR Underdrive alternator pulley, Electric Water pump with mechanical pump delete, Balance Shaft Delete, Honda Accord Timing Belt, Nology coil and wires, Throttle cam, Bursch Header, SLP pipe (cat replacement), Spin tech muffler, Na-Tune

I also have given a ride to a rennlist member sdstimson right when I just got my bursch header installed and was running the FrWilks chip. I am also willing to give anyone else a ride so they can feel the response of the mighty 8v NA engine.

 

Good of you to share this information, thanks.

 

Great compilation of mods/feedback!

 

Could you give some impressions of the Fidanzza flywheel? Did you do the mod with a bunch of others?
I have machined flywheels in my Datsun Z cars to reduce the mass (this was before lightweight flywheels were readily available) And it sure made a difference in the way the car revs. It did force me to adjust my driving style when pulling away from a stop, but was easy to adjust to and after a while I didn't notice.
I am approaching a clutch change in my 86 n/a and am considering a lighter flywheel, but am nervous about installing some kind of "racing" flywheel, that will make daily driving annoying. Besides getting a stock flywheel machined, there doesn't seem to be much options other than a Fidanzza.

 

I plan on writing the review for the fidanzza flywheel, rennbay wilwood brakes, and the short shifter kits from only944 sometime next week. This weekend I am in the process of moving to a new place.

 

I put the Fidanza lightweight flywheel in my '86 N/A. it revs much faster and I didn't need to adjust my driving style much at all.

 

Can you share how your electric water pump conversion is holding up?

I'm about to embark on the same project, minus the BS delete, and you are the only one I have found who has done it.

Did you end up replacing the timing belt tensioner gear with a smooth roller such as the balance shaft idler? If not, has the teeth on the tensioner gear caused any wear to the back side of the belt? I know that had some people concerned.

Is there are any recommendations that you have for me before I start that you maybe would have done differently after doing it the first time? Thermostat placement, water pump placement, reverse flow worth it, etc?

I'm starting the teardown either this coming weekend or the next and finishing the following weekend. I'm going to use the Davies Craig aluminum EWP115 kit.

 

The waterpump has been awesome I have had no issues with it at all. The best part is my next timing belt interval (in 8,000 more miles) it will only cost me $20. I used two Balance Shaft smooth tensioners. I originally used the toothed one but found the edge that holds the timing belt from moving off, was eating my first timing belt up. I shaved my head down .040" so I needed the extra tensioner otherwise the stock idler one is fine along with the smooth BS tensioner. Take your time with this project and if you expect it to happen in one day, anticipate another in case of surprised etc... As for thermostat placement, I do not have one as I am using the control unit with the Davis Craig design. I would recommend blocking or make the hole smaller, for where the water would circulate when the thermostat was closed (far right hold when you remove the water pump). You can do this with a custom plate or modding your factory water pump housing. I also did a right up on my conversion if you haven't found it https://rennlist.com/forums/924-931-...ater-pump.html Lastly if you want a heater you will need a smaller electric water pump to run the coolant through. I deleted my heater so I did not have to worry about that. Good luck!

For anyone else thinking about this conversion, it may cost about $1k upfront but it is a nice investment down the road if you plan on keeping your 944. I never have to replace my water pump and if the housing starts to leak I just replace the gasket. I also have 32,000 miles on this conversion and it runs just like a normal car.

 

Awesome thanks for the info!

I meant to type temp sensor placement, not thermostat. I am going to be using the Davies Craig control module as well so no need for a thermostat. I noticed in your thread you moved it to the heater block-off plate.

I didn't think about having a second pump for the heater though. I live in Colorado so the heater is mandatory to defrost the window in winter. I assume you need the second pump due to the fact the primary electric pump doesn't run constantly like the factory pump did, thus causing the heater to fluctuate temps depending if the pump is currently running or not?

Every project seems to cause 3 more lol

 

Yes I found the temp sensor best some place in the head and the heater block off plate was the best and easiest choice for myself. another place you could put the sensor is in the original water pump housing seeing as that part comes off and you would get a better read on the engine temp (touching metal) and not just the coolant temp.

Yes the fluctuation of when the water pump would be one is one of the two reasons. the second is because I reversed the flow of the coolant (through the head first then the block) this caused little to no flow going through my heater core. As water goes the way of least resistance. Also because you plan on keeping your balance shafts where you mount your main water pump will be different than mine. As I put mine in front of the top balance shaft, in replace of the BS pulley.

 

Modifications for review: Fidanza flywheel, Rennbay Wilwood brakes, only 944 short shifter and shifter arm.


Fidanza flywheel:

With holding the weight comparison is remarkable compared to stock. I remembered I did weigh each one but I can't remember or find my notes of where I wrote that down. Not only does this modification reduce the overall weight of the car but also the rotational mass of the engine. When I first installed it I had forgot about the grub screw on the flywheel so my crank sensor could read it. So this meant I had to adjust the screw after everything was put together. (Don't forget to do this and loctite the screw!!!!) Well 10,000 miles late and that screw came out and I had to put another one back in. I found them at home depot and used loctite this time upon putting it in. Again having to install it without removing everything was a delicate art in itself. So learn from my mistake Now the experience of driving with the flywheel. When I had installed this I had lived on a hill. A pretty steep one about a 45-50 degree hill (if you use a protractor) I noticed I had to rev a little higher than what I was used to go up, but nothing ridiculous. Driving around town on normal flat roads I didn't notice a difference in having to rev up higher (possibly from the hill everyday). Acceleration or better yet response time went up! I enjoy how with little flicks of my foot I could make the tach go up so freely. Also engine braking improved and I could slow down quicker and didn't have to use my brakes as much (unless I needed to stop of course). I enjoy having it there and as for daily driving for 12,000 miles I can live with it everyday. Even when I had to do an hour commute in stop and go traffic (only 17 miles).



Wilwood brakes

The first thing I did was weighed the brakes and I took note that the new brakes weighed 6.8 pounds less than the stock brakes. At the same time I replaced my rotors with slotted and drilled ones to reduce the time to cool the brakes (I know service area gets reduced). Before I replaced the brakes I had bleed the brakes to try and get better performance and as the brake pedal felt better stopping time was still a little scary in those emergence times. (pads where fairly new). Now with installing the wilwood brakes and after the brake in procedure the first thing I noticed wasn't stopping power but the response of turn in on the car. It made the car a lot sharper with turning response. Then I hit the brakes and wow can they stop. The best part is you can do it over and over and over again. Whereas before I would get brake fade quickly with the stock brakes but with the new brakes I haven't even felt like the brakes were fading. The pads I use are the "hybrid" of the street pads and race pads they offer. Before I wasn't able to lock my wheels up but now I can do it with ease. Meaning I need more tire up front for even better stopping performance. Although on dirt (rallycross) they do work well but I can feel (on the dirt at least) I need more braking in the rear. Which I can hope I can get Travis to make me some brackets for the rear. On the road or track they are more than enough to stop the car and the rears would not be necessary (unless you just wanted it for the looks). Lastly they look awesome and I love that they are in black and not the bright red or yellow.



Shifter/ Short shifter

The first thing I got was the shifter (inside cabin where the shift **** mounts). I noticed an immediate change as the huge amount of slop I had was gone. However after driving it around I did notice the slop would come back. The problem was the nut (yes it was a locking nut) would work its way loose and I would have to tighten it. Will I fixed that with a drill and cotter pin and haven't had any issues since. It feels nice to have that precise shift without all the slop and that is what this shifter does. All while retaining the stock shifter.

The short shifter (SS) was a fairly easy install. I like how you can adjust where you want the shifter position (I tilted mine as far as I could to the driver) to give you that adjustability of what feel comfortable. I got this SS right before Kyle sent an email out to everyone about adding the drilling and adding the cotter pin. Well I was curious and drove it around without doing that right away. I did start to feel the shifting feeling loose so after retightening it and adding the cotter pin I haven't had an issue. The amount that the SS reduces the throw is quite nice. He could have made the ratio smaller but I feel that would be for dedicated track cars. For something that is on the street and off it has a great feel and throw. I can shift the car without even thinking about missing a gear.

Lastly my own mod was the SS mount to transmission. I used two ball bearing rod ends on a double treaded stud. The reason for this was despite removing the slop there was still a hint of slop in the shifting. This do it your self modification removed that last bit and my shifts are 99% slop free. That extra 1% is from the shift **** mounted on the rubber twisting ever so slightly.

Mods on car not engine related:

Wilwood front brakes, Pelicanparts engine/transmission supermounts, Only944 shifter/short shifter, Only944 hatch rings, rennbay Stainless steel visor clips & hatch pins, Bilstein Shocks & struts, and gutted rear (seats, carpet, tools, spare, etc... removed).

 

oh wow you have done some great stuff.