2017 prep - Weight results for my TIs

[BlackBMWs]

These are my novice notes to share. I'm not so knowledgable on weight tuning, but I am intending to learn much more and apply it this season. Not much education in tuning yet, I just like to drive. I am posting this for reference for folks in the event anyone is interested.

So, last year was a more active track season for me with 11 days of track days and 7 AutoX days. ThunderHill, Auto Club, Laguna Seca and events with 2 regional Porsche clubs. Fun overall for my novice start. I had run 3 or 4 events of some sort in previous years, but last year was more immersive and consistent weekend fun.

I took one of our TIs and set it up for a street legal, weekend track car. I went with tires and suspension as my main improvement strategy along with grippy seats. The only engine mod for the stock M44 engine was to front Fogg the air box. It also benefits from a Stromung exhaust.

I noticed by the end of the season more of how the TI was handling. Predictable oversteer and faster lap times when I had a passenger in the car. I wondered if the balance in the car could be off. I worked to lighten the car, but I was faster through turns with more weight. I understand the benefit of downforce, but running with my wife in the car simply to get better laptimes seemed counter intuitive.

I weighed my M44 and S52 TIs this last weekend. The M44 was the car I used in 2016 and the S52 will be used this year for Track and AutoX events.


The scale system consists of four scales, one for each tire, a control panel and interconnecting cables. The scales read the weight present at each tire, displays it and calculates the % of weight at each corner. Then it is able to present that data in a few ways: Total, F/R %, side to side% and diagonal corner to corner.

I post those readings for both cars in pounds. It can also present in Kilograms. I also took another set of weight readings with me in the drivers seat to see the balance changes with driver and helmet. I can post those if anyone is interested.



First set of numbers are for the 98 M44 Cali Sport, 3/4 tank of gas, no driver. Rear seats removed. CA Tuned Coliovers, F/R Mason strut braces, X brace, racing Dynamics F/R sways, Z3 steering rack, Style 68 staggered with RE71s, Bride Low Max bucket seats E36 vented front rotors, 525 rear calipers, Hawk HP+ pads. Front fogged air box and Stromung exhaust. Spare removed.



Total weight -


Front vs. Rear weight balance -


Right vs. Left balance -


Drivers side front to Passenger side rear -


Drivers side rear to Passenger side front -


What was interesting to me was the F/R % in that the % up front was higher. Made sense as I pulled out the spare, its holder, stuff in the tool kit, rear seat and panels and only added a light rear strut bar.

In retrospect, I wonder aside from lightening the car, if a CF hood help balance the car out to a material advantage?

The other thing was it was heavier than I thought. Then thinking the thicker sways, x-brace, bigger calipers, strut bars all add up. I did lose about 64 pounds tho is swapping the stock Sport seats for the Bride Low Max buckets. My goal last year was to handle with the Miatas on the track. By the end of season, the TI ran well with the Miatas and WRXs. I was able to out corner and out brake most others bigger and more powerful cars in my grouping. Of course I got blown away in any longer staightaway. I got good at the pointed finger in those cases, only to be a nuisance again in the twisties.

I want to take any observations and learning to the S52 TI for this season.

-—----------------------------------

1998 TI Sport w/S52 - 1/2 tank full, mostly stock, nothing really removed yet, K1 16x7 w/RE-71s square, x brace, Megan front cross brace, CA Tuned Coilovers, Subwoofer. Alum radiator. Spare removed. Fan delete, 16" electric fan, Borla exhaust.



Planned mods: Strip interior and replace sunroof cartridge with fiberglass insert, Z3 rack, caliper and pad upgrades, HR sways, a rear Mason brace/harness bar to be replaced with rear cage later, Bride Low Max buckets and 6 point harnesses, diff swap, CF hood, alum door panels, alum expansion tank.

Yellow and Red plastidip as well.

Total weight -


Front vs. Rear weight balance -


Right vs. Left balance -


Drivers side front to Passenger side rear -


Drivers side rear to Passenger side front -


My last total S52 reading in KG for Samdemange.



My target for the S52 is 125 pounds lighter and better F/R balance after the mods.

I'll weigh my Wife's Ti for comparison as it is more stock than these other two. Just suspension upgrades.

I am just learning tuning considerations and will always welcome comments and experiences.

Cheers! Rich

[anassa]

Very Very interesting!!!

Thank you for sharing.

Have you thought about going with an aluminum m52 block? I did my swap with an m52block/s52 head just in case I can eventually retire it from daily duty to a track/autox car I can build/swap an aluminum block to help the weight saving and weight distribution. (Well... it just turned out that way lol, but I eventually want to take advantage of it)

You also never mentioned the differential, are they both small case 3.45 diffs?

[BlackBMWs]

Thanks! You all have helped me along with your experiences, so, I am always motivated to give back.

I am actively watching for a donor Z3 2.8L 5 speed to swap into last year's track TI. That would raise the awesomeness for AutoX for sure. More power and not a big weight penalty.

The M44 uses a small case 3.45 LSD. The S52 uses a medium case 2.89 LSD which I am swapping out for a rebuilt medium case 3.25 LSD.


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[wolferj-RIP]

The last time I weighed my swapped ti, it was just over 2900 lbs, with a 51/49 weight ratio bias. That was with a full interior (including Vader seats) and a battery relocation to the rear. I did this on a truck scale, so my results are not nearly as detailed as Rich's...

[Baas 009]

Very interesting topic! And hello for all from Finland!

BlackBMWs canvas roofed racer seems bit heavier than my tintop...

Here's some readings, in kilograms of course because europe
No idea what value is REAR_BITE, please tell if you know.

LF 333.5
RF 331.5
LR 279.5
RR 270.0
TOTAL 1214,5
FRONT 665
FRONT % 54,76
REAR 549,5
REAR% 45,24
REAR_BITE 9,5
LEFT 613
LEFT% 50,47
RIGHT 601,5
RIGHT% 49,53
CROSS_LF_RR 603,5
CROSS_LF_RR_% 49,69
CROSS_RF_LR 611
CROSS_RF_LR_% 50,31

This is -95 318ti without driver, 3/4 tank, 205/50/16 Federal RSR:s on generic non-OEM aluminium wheels, vented 325 discs front, removed spare and holder, jack, tools and warning triangle. All upholstery stock, no race belts etc. Stock suspension.

Car is equipped with M42 which wasn't available in US if i remember right. -95 was last year of M42 also in Europe. Manual AC and power windows, originally sold to italy , imported to far north much later, with only ~100k on clock.

Some more readings including driver, (me ~70kg). Others same.

LF 356.5
RF 341.5
LR 302.0
RR 284.0
TOTAL 1284
FRONT 698
FRONT_% 54,36
REAR 586
REAR_% 45,64
REAR_BITE 18
LEFT 658,5
LEFT_% 51,29
RIGHT 625,5
RIGHT% 48,71
CROSS_LF_RR 640,5
CROSS_LF_RR_% 49,88
CROSS_RF_LR 643,5
CROSS_RF_LR_% 50,12

Car had some crash damage on the end of last summer, now trying to get it going again. Will be lighter, battery has already lightened ~10kg, also throwing out rear seats and other unneccessary junk...

[BlackBMWs]

Thanks for sharing your stats! Hello from California! Here's my readings in kg. Mix of driver/no driver. Look like I missed a F/R ratio in KG driverless.

Yup, I wanted to use my slicktop before it got hit for the weight savings, Is yours a sunroof delete? I wonder if the differences are the suspension components and the ~35lb California top cartridge and the roof reinforcements. Seems about a 28lb difference. Hmmmm. Need to look for another slicktop. Yours will be another 20-25kg lighter when you remove the rear seats and trim. I am running a little wider tires.

I am on stock, staggered Style 68s presently with RE-71 225/245s tires on the Cali. Should be lighter on this years car with the Square K1s, Also the Bride seats are 29lbs each with bracket and slider while the stock sport seats are 66lbs IIRC. I will remove the Sunroof Cartridge in favor of a fiberglass insert. ~50lb savings, especially up high.

I will go CF for a hood on the S52 as when I remove the upholstery, it will only worsen the F/R balance.

Thanks again, I appreciate the weight comparison.



No F/R reading without driver in KG.








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[Baas 009]

Yeah, the difference is only minor, some variation in fuel amount can do that also. And beefier tyres are somewhat more heavy.

Mine has no sunroof at all The California top definitely adds some weight as being like giant sunroof, and even standard sunroof assembly weighs quite a lot.

Also, my car has non-sport seats which probably are bit lighter, will be replacing those also in some point with proper buckets. Target to final weight is under 1200kg with M52B28 engine, ZF box, complete rollgage and other race equipment. I'll convert the car to six-banger probably after this season, have no time to do it now if I want to drive this summer.

[BlackBMWs]

Yup, watching for a Donor Z3 for the same motor and drivetrain for last year's track car, which I will revert back to a daily driver. I just have to peel off all the yellow Plastidip.

Are you considering any brake work for the upgraded build?


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[Baas 009]

Big-engine Z3 is pretty rare here, i have 328 touring as parts donor. Not sure if those have ever been sold in US. Was it so that all e36:s have iron block engines in US?

I have already upgraded front brake discs and calipers to 325i models, which are the same size but vented. IMO no need for brake upgrade with m52. Here in Finland we have race series called BMW Xtreme, cars are E36 325i Sedans and Coupes. Those have ~200hp, at least the weight of the normal compact, and they blast 1 hour races on insane speed with standard brakes, only with race pads, brake fluids and cooling air ducts.

I have to make rollgage and suspension upgrade before engine swap, and engine needs some small overhaul before swapping to compact. Also, I'll try to get car MOT also with the B28, but due to awfully strict regulations here i have to get whole rear axle of 323ti somewhere to get it legal Those cars are also pretty rare here, and rear suspensions for those are rare as chicken teeth, because of it's popular swap to e30 also to get 5-bolt hubs and disc brakes...

[BlackBMWs]

Ya, here the alum block M52 only came on the 97-98 Z3s. Getting harder to find. Is the M52b28 fairly prevalent in Europe? Which models?

I have similar brake setup except I have E34 rear calipers, SS brake lines and Hawk HP+ pads. For the short 20 minute track sessions I run, it's plenty of brake, no fade.

I always watch for a 97-99 M Roadster Z3 as a parts car for a spare S52 as well as the rear axle assembly. That one is as rare as Chicken Teeth to show up for auction.

The race you mention sounds fun. Do you run in any of the Compact Cups or is that another class?

What are you planning to run for suspension?



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[Baas 009]

S52 is very rare in europe, because e36 M3 did not have it on europe, we had S50B32 because in europe obd 2 wasn't needed until year 2000.
I believe M52B32 was a typo, as B28 was biggest M52...

I don't run in any race series, car is only for trackday use. Compact cup is running in UK, and seems very nice. Here in Finland we have that Xtreme cup, which indeed has 2 forms, racing cup and rally cup. Regulations are pretty much the same so you can convert the car for each other quite easily. In racing cup, there is 2 starts in one day, about 15 lap sprint race and the 1 hour endurance race. Most of the teams have 2 drivers, and they swap in 1 hour race as there is 1 obligatory pit stop for everyone.
E36 325i and M3 are very popular rally weapons in national rally series, where the FIA classification has to be expired at least 5 years before car model can entry.

I'm planning to install BC-Racing BR Coilover kit, Chinese, yes, but not the cheapest, and many bmw drivers have good experience on those. Features independent ride height and spring preload adjustment and not combined as in many cases.
In fact, i'm planning to use e36 M3 type front struts as the stabilizer connects to strut and is more effective, and e30 coilover type rears, as those are not available for compact. Luckily we have very good dealer in Finland who can make custom combination just for pennies...

In front brakes I have used EBC yellowstuff, works ok but could be better. Hawk HT10 would be very interesting pad, but hawk availability is very poor in europe. Probably going for Carbone lorraine or ferodo next. Rear brakes have some unidentified pads which came with the car, i have run about 500km on track with those and wear is barely noticeable. Probabaly made from rock in china, and braking power is probably also in same level...

[anassa]

Originally Posted by BlackBMWs

Thanks! You all have helped me along with your experiences, so, I am always motivated to give back.

I am actively watching for a donor Z3 2.8L 5 speed to swap into last year's track TI. That would raise the awesomeness for AutoX for sure. More power and not a big weight penalty.

The M44 uses a small case 3.45 LSD. The S52 uses a medium case 2.89 LSD which I am swapping out for a rebuilt medium case 3.25 LSD.


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Wow, great to hear that some of my post have helped others!

I reallly like that your showing actual numbers with details on what you did so others can compare or copy. I will be paying close attention to your setup with the s52, or even more the 2.8 if you get that in there.

Why the choice for 3.25LSD? Just ratio wise, its a great ratio from what I can see, not dogging it all, I won't mind it myself, but why not 3.46?

Are you doing anything to reinforce the rear? Garagetastic seems to have a simple way to convert to a dual ear that might help some of the twisting that will happen with a single ear.

https://store.garagistic.com/e30-secondary-diff-mount

I have thought about going with it eventually.

Originally Posted by Baas 009

Very interesting topic! And hello for all from Finland!

BlackBMWs canvas roofed racer seems bit heavier than my tintop...

Here's some readings, in kilograms of course because europe
No idea what value is REAR_BITE, please tell if you know.

Car is equipped with M42 which wasn't available in US if i remember right. -95 was last year of M42 also in Europe. Manual AC and power windows, originally sold to italy , imported to far north much later, with only ~100k on clock.

Thanks for sharing too! Here in the U.S. we did get the m42 in the 1995, but 96+ are all m44.

You should also post up a thread with pictures of your car and how you build it! It will be interesting to see a Finnish build.

[anassa]

Originally Posted by Baas 009

I have to make rollgage and suspension upgrade before engine swap, and engine needs some small overhaul before swapping to compact. Also, I'll try to get car MOT also with the B28, but due to awfully strict regulations here i have to get whole rear axle of 323ti somewhere to get it legal Those cars are also pretty rare here, and rear suspensions for those are rare as chicken teeth, because of it's popular swap to e30 also to get 5-bolt hubs and disc brakes...

What is different about the 323ti rear end compared to the 318ti? is it just the differential/axles?

As for brakes and Hawk pads or parts, does bimmerworld/tunermotorsport/ecstuning ship to Finland?

[Baas 009]

Originally Posted by anassa

What is different about the 323ti rear end compared to the 318ti? is it just the differential/axles?

As for brakes and Hawk pads or parts, does bimmerworld/tunermotorsport/ecstuning ship to Finland?

Thank you for comments!

323ti and 318ti rear end have almost all parts different. Only common parts are rear beam (which attaches to body) and brakes (discs, pads, calipers). All other parts are different, at least for number.

Yes, Hawk pads can be ordered from America also, but added toll + vat rises the price to sky. That's why I prefer getting parts inside EU ad there is no VAT and toll on that case.

Maybe i'll do project topic, but where it should be located? I haven't noticed particular subforum for projects?

[samdemange]

i have made an excel tab for the corner weight with auto calculation it look like this



link for download: https://mega.nz/#!7FRgnJrR!abBzQb5ts...P3VuYFaa5uuZPw