89 S52 Swap

[cdl723]

This last post has some pics from an indycar race i went to in long beach, CA while visiting my brother. I also have some pictures from cars and coffee Richmond, VA.







pc: chinampa for the last 2

[cdl723]

So I got an E90 Booster and master to swap over to make the brakes feel more modern than the 944 booster. Unfortunately at the same time a fuel hose at the back of the engine developed a pin hole leak and soaked the coolant hoses. One of the coolant hoses burst... It happen to be at my high school with some high school friends who also had/have E30s. We swapped the hose within an hour or 2 and had the car driving well enough to limp it home.



While I was properly fixing the hoses I installed the E90 booster. The pedal is about 1/2" low so I will need to pull it and thread the shaft for a clevis to adjust the pedal back up. The longer clevis from the e28 was out of stock from local dealers so I ordered this part from McMaster 2448K51. It seemed to match up to the width, length, pin diameter and thread pitch. I will install it early next week and report back how it works.



Lastly the KYB AGX MR2 struts are a little harsh in rebound so I am looking at alternate shock options. I have heard a lot of good things about Koni and have liked the cars I have ridden in that have the SA Koni Yellows on them. I asked a koni rep about some common E30 cartridge replacements and he sent over the shock dyno results. I was originally thinking the 325IX, but they may be a little too soft on rebound and I do not want to run the shocks on full stiffness as they'll probably get softer over time. Here are some of the specs and to my knowledge the rear MR2 struts are roughly 2" shorter. The 325IX and G60 struts are 3-3.5" shorter.


8641 1021Sport (E30 325i)
Tested at .33m/sec
Compresion –500N
Rebound –870N (rebound doubles at full firm setting)
Tested at .13m/sec
Compression –320N
Rebound –550N (rebound doubles at full firm setting)

8641 1144Sport (E30 325Xi)
Tested at .33m/sec
Compresion –500N
Rebound –600N (rebound doubles at full firm setting)
Tested at .13m/sec
Compression –320N
Rebound –300N (rebound doubles at full firm setting)

8641 1221Sport (MR2 Rear)
Tested at .33m/sec
Compresion –500N
Rebound –1470N (rebound doubles at full firm setting)
Tested at .13m/sec
Compression –320N
Rebound –700N (rebound doubles at full firm setting)

8641 1198Sport (G60 Corrado)
Tested at .33m/sec
Compresion –700N
Rebound –950N (rebound doubles at full firm setting)
Tested at .13m/sec
Compression –500N
Rebound –560N (rebound doubles at full firm setting)

[Northern]

I'd never seen results like this, I ended up using the 8610-1437-RACE, but no idea how they compare.

I've been in a 24V touring with 450lb front springs and the iX Konis and it felt ok, but seeing the G60 rates, I'd honestly say that's the winner.

[cdl723]

I did a few more calculations with the numbers the Koni rep gave me and determined the 325IX struts might be better for my spring rates. I am aiming for a natural frequency of ~1.5Hz which is around 200-300lb/in for the front and around 500lb/in for the rear depending on the weight of the car. I currently have 300f/500r and the natural frequencies of my suspension are ~2hz/1.8hz.

The 325IX konis would give me a damping ratio of ~0.25-0.45 which is ideal for a sporty street car. Using Koni's rebound numbers for the MR2 struts I have a damping ratio of ~0.7 in rebound which probably explains why I feel like I'm skipping over bumps at high speeds.

I know I probably would have been just as good off with H&R Race/Sports with Koni Yellows, but I enjoy calculating all of this and being able to change it easily.

--- References ---

Common suspension frequencies:

• 1.0 Hz - passenger cars
• 1.25 to 1.75 Hz - sports cars
• 2.0 to 2.5 Hz - autocross and racecars with low downforce
• 2.5+ Hz - high downforce racecars
• 1.45 Hz - Subaru BRZ (front and rear)

https://www.racecompengineering.com/...on-frequencies

https://www.researchgate.net/figure/ehicle-typical-damping-coefficient_tbl1_245401813

[cdl723]

I was able to replace the other coolant lines at the back of the head and get some work done on the brake booster. I think it is safe to say id have some more problems with the 30 year old hoses if I kept driving it this way. I am pretty sure this is how the coolant lines route, but can someone verify this as I cannot find it one way online? I have the back of the block going to the bottom and top hose going to the coolant pipe on the engine.



As for the booster, I cut the clevis off and cut m10x1.5 threads. It looks like the 60mm McMaster clevis will work, but it is a hair too long (maybe 5-10mm). I will trim the clevis and try again. I am a little concerned with thread engagement so I will trim a small amount at a time to keep the most threads engaged. I threw the locking nut on there and put the booster in to get an idea of how it would fit. I am pushing the booster against the fire wall in the last pic to get an idea.



The last thing I need to do is create brake lines. I decided to ditch the adapters and make new lines from the ABS unit to the master cylinder. I need to find a good spot to put the proportion valve for the rear brakes. I was thinking around the ABS unit, but I am open to suggestions.

[cdl723]

I trimmed down the clevis a few mm so it would fit properly without engaging the brakes. I believe this part was 20mm to begin with.

I was able to cut the clevis down some and create new brake lines. Here is my first line.

This flaring tool seems to work a lot better than the generic HF tool. It grips about an inch of line and holds it still while it flares the end.


Outcome:

[cdl723]

Not too many updates, but I got the brakes all straight and they feel good. I put some new engine mounts on because the revshift mounts were causing my engine and trans to be misaligned. I went with AKG mounts and there is a ton of clearance now for the booster. I did have to hammer the exhaust a little to clear the control arm bushing, but I also need to re do the whole exhaust.


I also found a 420g SMG from an E46 m3 for free on marketplace. The only catch was it felt like it was stuck in 5th gear, but I can shift it into other gears and lock it up... Im guessing either a shift fork is broken or one of the pins for the shifter mechanism/lockout in the casing is misaligned. Oddly enough I am unable to get the shift fork to move for the front gear set. Is this for 5h/6th or is it one of the other gears in the back half? I ordered a deep well 36mm socket so I can remove the rear half and investigate some more.

[cdl723]

Well i got the rest of the trans disassembled.


Everything looks good internally, but the input shaft feels like the needle bearing is seized inside of the shaft with the gears. At least thats what I'm guessing because the input and output spin at 1:1 and it locks up when I shift into any other gear. The input shaft also looks like it moved a good bit with the wear on the selector ring and I was unable to get it to shift into the gear closest to the input (5th?).


Any insight/suggestions as far as what the issue might be would be greatly appreciated.

[Panici]

Just read through your thread, looks like some good work!


Saw you removed power steering and then added it back. Was the steering just too heavy without the power assist?

[cdl723]

Just read through your thread, looks like some good work!


Saw you removed power steering and then added it back. Was the steering just too heavy without the power assist?

I didn’t think it was too bad. I added back so my Fiancé could/would drive it

[Northern]

Appreciate the review/link to that flaring tool, I have 3 shitty flaring tools that are basically useless for anything other than copper, and I'm going to be doing a full set of lines sooner than later so I'll probably pick up one of these.

[cdl723]

I have been busy for the last few months getting a new proper custom exhaust and painting the car. I my old exhaust was leaking a little and sounded good, but I wanted to put long tube headers on and redo it correctly. I decided to do a custom dual 304 stainless exhaust with stainless bros resonators and mufflers. I like the new exhaust and it sounds good at WOT, but everyone knows I am there lol. I ordered some cats to weld in so hopefully it will tame the noise a little.

I decided to put 325ix Koni Yellows on. It finally feels like a street car with a suspension that works! Unfortunately I had an oversight in that the overall strut length was shorter than the MR2 struts. This resulted in me preloading the spring a good bit to get it to a functional ride height. I was still about 3/4"-1" lower than before and made some strut mount spacers. This brought the car up to a reasonable ride height and the car sits with ~3" of compression and ~1" of rebound travel at static ride height.

[cdl723]

I prepped the car and pulled off a lot of trim for paint back in the end of march. I was trying to have the car done by Hyperfest May 19 for my bachelor trip as i signed up for a trakcross. It was not done by then and luckily my Fiance let me take her Passat. It was slow but fun on the Patriot course at VIR. I got the car back June 10th from the painter in a non running state. Luckily it was a somewhat easy fix with 2 of the engine relays getting stuck and failing. I just finished getting the car back together with everything and am very happy with the results. I wanted it back before my wedding next Saturday to use it as a get away car. The only downside is the painter tried installing the sunroof seal without removing the sunroof and it got stuck under the sun roof and no longer moves. For some reason he decided to cut the seal and leave it in the tracks. Does anyone know how to open/close a sun roof that doesn't move with the manual crank and feels like the cables broke off the sunroof?

[Panici]

Exhaust looks clean!
Where did you get those tips?

[cdl723]

Exhaust looks clean!
Where did you get those tips?

They are from 42 draft designs. Its their brushed double walled stainless tips.