S38B38 into my 1977 e12 chassis'd 633CSi

[Shipper]

My next tyres will be race semi-slick but road registerable. Yokohama Advan AO50. I'll want to do a few track days every now and then.

[crime]

My next tyres will be race semi-slick but road registerable. Yokohama Advan AO50. I'll want to do a few track days every now and then.

you should try Bridgestone Potenza Adrenalin RE003, I am running Adrenalin RE002 and they are great! I can only imagine, what would the RE003 be like

[Shipper]

you should try Bridgestone Potenza Adrenalin RE003, I am running Adrenalin RE002 and they are great! I can only imagine, what would the RE003 be like

I'm sure they are a brilliant road tyre. The Yokohama Advan's are a race semi slick. They are worth 1 second per 1km on a race track. On a 4.5km race track they'll save me 4.5 seconds. Despite being semi-slick they are not a wet weather tyre at all.

As I'll do some track work, once I've stuffed the current tyres I'll go the semi-slicks. Luckily they are road legal.

[GazM3]

The only problem with the semi slick is for road use the constant heat cycles make them lose grip before the tread has worn out and the road noise is like you have 4 crook wheel bearings. Not sure about the Yokohamas specificallly but the toto 888 tyres I had on the 6 for a while were initially great but went off pretty quickly.

The new generation of "autocross" tyre that are around treadwear 140 (hankook rs3, Bridgestone re71r, Michelin pilot sport cup2, etc seem to be the tyre to be on for the occasional track day going road car using same SET of tyres. The only ones available in Aust in 17" are the hankook rs3. On the m3 back in the day I was a regular track day warrior I had 2 sets of wheels / tyres. The Hoosier r6 for dry track days and Michelin pilot sport 2 for wet track days and road use. The Hoosiers once warm were worth at least a second over other r compound track tyres but did not work in the wet or even were very sketchy on the first cold lap. I tried a set o Hoosier a6 with the softer rubber were good straight away but went off after a few laps of abuse.

[crime]

Bought some VDO gauges today, will fit them where the cassette holder is now

vdo.jpg

[Shipper]

Nice, my PLX multi gauges will go in early next year.

[Shipper]

The head is back, all machined perfectly flat.

The 293/279 CATCAMS are in. The performance springs and retainers are in. The performance high strength valves are in. All looks good.

The machinist had to machine the internal walls to allow the cam lobe to rotate. You can see this from the photos.

Timing will be the next big thing. I also need to chase down adjustable cam gears so that we can tune to half or a quarter of a cog if needed.


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[euroshark]

Looks like a serious pair of cams! How much lift are they to require machining around the tappets?

[Shipper]

293/279 degree race/rally cam. This is the lowest race catcam (endurance race cam) and selected so I do not lose lowdown torque. Any higher and everything happens above 4000rpm.

12.45mm/12.0mm lift. 4.0mm/3.4mm at TDC so clearance an issue and needs to be checked, a lot! The Group C 635 running 420hp runs the next cams up, 299/294 so my setup is very aggressive for the road and track-able. The highest performance cam catcams make for racing is a 303/293. Dyno late Jan 2017 as holidays slow things down. Cannot wait to drive it in 2017 with the 5 speed manual and the new shorter large case 3.73 LSD.

The head (cam box) was bent like a banana. they had to machine the centre down. The catcams would not turn as they are hollow so flexed. The stock cams are solid so could handle the flex in the head. Flex gone now and head is perfectly flat on all 3 faces (head comes in 2 layers so 3 faces in total). Both catcams together were just a little lighter than one single stock OEM cam.

[GazM3]

Hey. Just get your machinist to slot the oem wheels. The harness of the oem BMW wheels is right up there so it's not a job for amateur. Cams selected will make it nice and grumpy down low that's for sure especially with te compression on the low side for the application. Having adjustable cams will help with the tuning and to help marginal piston to valve clearance

[Shipper]

Engine together and back in the car with the big cams and high performance valves and springs. Need a week or two to finalise bolts, fitting. Will replace the S38B38 tensioner with an S50 tensioner. Need to review drive shaft length with large case 3.73 LSD. Dyno towards the end of the month with the megasquirt installed.

Big Cam Engine Back Together.jpg

[Shipper]

The only problem with the semi slick is for road use the constant heat cycles make them lose grip before the tread has worn out and the road noise is like you have 4 crook wheel bearings. Not sure about the Yokohamas specificallly but the toto 888 tyres I had on the 6 for a while were initially great but went off pretty quickly.

The new generation of "autocross" tyre that are around treadwear 140 (hankook rs3, Bridgestone re71r, Michelin pilot sport cup2, etc seem to be the tyre to be on for the occasional track day going road car using same SET of tyres. The only ones available in Aust in 17" are the hankook rs3. On the m3 back in the day I was a regular track day warrior I had 2 sets of wheels / tyres. The Hoosier r6 for dry track days and Michelin pilot sport 2 for wet track days and road use. The Hoosiers once warm were worth at least a second over other r compound track tyres but did not work in the wet or even were very sketchy on the first cold lap. I tried a set o Hoosier a6 with the softer rubber were good straight away but went off after a few laps of abuse.

So Gaz, these? https://www.jaxtyres.com.au/tyres/br...ntus-r-s3-z222

[Shipper]

Chain tensioner from the S50 has been purchased from Pelican Parts. Should be here mid next week. Post installation next week we are off to the dyno for a tune and to see what this build can do.

[GazM3]

Must be exciting.

Yes josh the rs3. In pretty sure there is a series 1 and 2. Soon as my m635 is back working in getting a set. Only negatives is they are a tad noisier than run of the mill road tyres and the wet grip will not be in the league of the Michelin pilot super sports. Dry grip should be orsome and without the heat cycling issues (constant heating up and cooling down) that plague R compound tyres when used as road tyres.

[Shipper]

Must be exciting.

Yes josh the rs3. In pretty sure there is a series 1 and 2. Soon as my m635 is back working in getting a set. Only negatives is they are a tad noisier than run of the mill road tyres and the wet grip will not be in the league of the Michelin pilot super sports. Dry grip should be orsome and without the heat cycling issues (constant heating up and cooling down) that plague R compound tyres when used as road tyres.

I had a read of the tyre Gaz. A good performance road tyre designed for track days. So probably down on a road legal track tyre but, a few seconds quicker than a high performance road tyre. I'll get a set. Price looks decent. $229 a wheel is not too bad. My track tyres in 15" where $400/w. And my 633 runs 17". Thanks for finding these.

[GazM3]

From what I here they are a wide fitment so a 225 wide nearly as wide as a 235 of another tyre. I'm going to put on 225/45 on front and 255/40 on rear. I have bought a guard roller just in case

[Shipper]

My timing chain tensioner from the S50 just turned up. I'll get this to my mechanic by Wednesday. As soon as it is in and he let's me book the dyno we are off. Man these things take forever. So close to starting the hot street engine. 370hp plus would be lovely.

[eric1ono]

Nice progress! What did you end up doing for your cam gears?

Thanks,

Eric

[Shipper]

S50 timing chain tensioner in and engine started. Need to adjust the valves. Additionally, the drive shaft is tight (we placed a large case 3.73 LSD in place of the medium case 3.46 LSD) and the mechanic wants to modify it prior to going to the dyno. Hopefully next week we finalise the drive shaft then book the dyno.

The machinist will look at slotting the cam gears at the same time. Easier than buying.

[Shipper]

Engine sounds fantastic. Very mechanical German precision mixed with big cam straight 6 wail (think Batwing CSL racer). Will redo shims as some adjustment needed post first run and adjustment. Finalising prop-shaft and LSD position prior to running on Dyno. Should be booking dyno next week with luck. 6 speed gearbox bought (from the e39 M5) and this will go in later this year as we have a 6-8 week shipping time to Aus.

The getrag 420G 6 speed is pretty much a 5 speed dogleg with 5th at 1:1 and then an overdrive 6th. So it's the 5 speed dogleg with the 5th gear in the 5 speed overdrive added as a 6th gear. Acceleration will increase with top end cruising remaining unchanged from the 5 speed overdrive. Try and catch me then Porsche's!!!

[tschultz]

What do you have to do to adapt it to the M30?

[Shipper]

No idea, although I do know a guy running the 420g 6 speed getrag on his M30. The 1994 S38B38 M5 came with this gearbox so for me it is a direct bolt on. As my 5 speed overdrive was also a direct bolt on to the S38B38 there's probably not a significant amount of work to get it hooked up. You may need to swap or modify bell housings. The 420g was also supplied with the E46 M3 but used a slightly different bell housing.

It weighs 10kg more than a 5 speed manual and is longer. So you will need to modify the prop shaft.

[GazM3]

Sounds like you are close.
The 420g may be tricky as it's a fair bit larger than the boxes that normally go into the e24. Im pretty sure there are a few adapters floating around. Samsonas makes an adaptor from the modern s50/m50 to m10/m30/m88/3/s14/s38 family but u may have to do the old cut up an old bellhousing and fuse onto the 420g. I have a spare 420g I picked up and was thinking the same as u as the last trip with the dogleg the revs were sitting up around 4000rpm at about 125kmh. First gear is quite short compared to the dogleg. The same combo works nice in my m3 which has 3.62 diff. I guess u will have close to 8000rpm but u will be still short of 100kmh in 2nd.

You are going to need some grippy rubber and a strong working lsd mechanism to convert the engine power to forward progress especially from the traffic lights

[Shipper]

Sounds like you are close.
The 420g may be tricky as it's a fair bit larger than the boxes that normally go into the e24. Im pretty sure there are a few adapters floating around. Samsonas makes an adaptor from the modern s50/m50 to m10/m30/m88/3/s14/s38 family but u may have to do the old cut up an old bellhousing and fuse onto the 420g. I have a spare 420g I picked up and was thinking the same as u as the last trip with the dogleg the revs were sitting up around 4000rpm at about 125kmh. First gear is quite short compared to the dogleg. The same combo works nice in my m3 which has 3.62 diff. I guess u will have close to 8000rpm but u will be still short of 100kmh in 2nd.

You are going to need some grippy rubber and a strong working lsd mechanism to convert the engine power to forward progress especially from the traffic lights

Gaz, my engine came with a 420G getrag in 1994. It was a bolt on. I may need a conversion plate but this gearbox was stock for an S38B38 in it's last year.

I've got the large case 3.73 LSD that came our of the e34 M5. So I should be okay there. Gearbox is purchased and on it's way.

I should run to 7500 rpm safely with an ECU tuned redline at 7750rpm.

The gearing speed calculator with my setup says 309km/h at 7750rpm and 110km/h at 2750rpm. I'm happy with the 110km/h rpm level. 100km/h is 2500rpm. In all fairness, this is the same rpm/speed as per the 5 speed overdrives 5th but, with far quicker acceleration. So you get the acceleration benefits of your 5 speed dogleg and the cruising benefits of the 5 speed overdrive. win/win.

https://e28goodies.com/gearing-calculator/

[GazM3]

there are 4 types of bellhousing for the 420g gearbox.

type1 for s50 engine bmw e36 m3
type2 for v8 m60/m62/s62 engine for e34/e39
type3 for v12 m70/s70 in e31
type4 for s38b38 in e34 m5 nurburgring edition

type1 & type2 are common
both the type3 & type4 are super rare