Originally Posted by MatheusS50
did you fit this M88 header in your S38? Did you have problem with clearance? Is this M88 header 50mm primary pipes ending in both 58mm collectors? could you take more pictures of flange side?
Thank you to share with us this nice picture..
I made a lot of pictures for us to compare M88 vs B36/B38 vs S54
I dont want to post 10+ pics on this post because it is passos thread and they are too many pics, I will open different post were you will see the measurements I took.
As I have mention earlier the M88/3 will fit the S38 engine. The M88/3 headers are more close to the cyl head and they are much more Compact
vs. B36-B38 headers. Soon I will make a imsa e34 m5 report, they used it. The M88/3 were designed for pure power and no cats no emissions just free flow. If I were you I would use on passos project/car M88/3 headers with modified secondary pipe to start from 2.5 inch=63.5mm going into huge 'X' pipe so the exhaust gases will cross flow, are you going to use single or dual exhaust ?. The owner of the E26 M1 is using this combo since years and years when he is building performance S38. The result is amazing. Unfortunately they are not 50mm as for example the primaries on the S14 Gp A header are larger If I am not mistaken they are 50mm all the way. You can not beat the performance out of the M88/3 for the money, remember imsa e34 m5 with ~430-450hp was using m88/3 headers.
Often I hear people say don't go with dual 2.5=63.5mm you will lose lots of torque, in my opinion that will be for 4cyl engine not 6cyl with 3.8 displacement...passos M5 is lucky to have 6 spd gear box the gear ratios are very well set and will always climb the revs fast and with the free flow exhaust that it will be very nice outcome and results.
The M88/3 headers were design to fit the E24 M635CSi and E28 M5 EURO from the factory. You will never ever fit S38 either B36 B38 headers on E28 M5 or M635CSi/M6. I made a pics below on the wood plot to simulate a cyl head flat surface so you can see how compact they are. As yo can see #3 or so, is a problem and it is sticks to much out.
Originally Posted by MatheusS50
By the way, i can imagine how strong is your E30 with S38 engine, because my customer GrandRoyal, that i built a S14B25 to his M3 E30, is a rev eater (itīs over 8.000rpm with power curve keeping push) and itīs pull very hard.. i like so much the smaller brother of S38.. is a rev happy engine by his bred..
Bit off topic:
Years ago when I build my E30 M3 3,6 that car is so much fun to drive that at some point I was filing full tank of gas 2 times a day! Scaled the car at 53% front 47% rear a bit heavy nose, that is the reason I sold it. Aside from my race car project e24 m6 I am working on my second E30 M3 with that B38 engine. The engine will be pushed in around ~5-7 inches, dry sump to get rid of the oil as weight and agains foaming etc.. knife edged crank ~10 pounds, fly wheel ~5pounds, ABS in trunk, race alternator half the weight etc..e36 m3 late year arms for caster to extent the wheel base with a little bit.. I will target to get as close to ~51% will see...Because when I scaled my car I add about 70pounds inside the chassis and the trunk area and I was able to reach 48% front with no problem. And the car will receive this time 285/30/18 all around and the over all diameter will be equal as on 245 40 17. The owner of the M1 owned a E30 M3 S38 with Shrick cams and some tune head work etc.. and was pushing ~330rwhp, drove the car many times at the track and was able to outperform any S14 powered e30 m3 2.5 race engine just name it...on a bmw race track event. Look at Jari's e30 m3...I dont think even a factory dtm will be able to keep with his m3.
Yes, S14 is a rev eater, happy light weight internals you have 2cyl less, less cam shaft mass, less crank shaft... less valves etc... all that make it S14 rev screamer.
Matheus if you never seen my E30 M3 S38 3.6 you can click hear EURO Classic Motors | For Sale
Keep us update with the nice project. It will out come amazing fun car