Thought on how an E82 128i would fare in SCCA TT Sport 5?

So, I've been prepping my 128i for track work next season, thinking I would build it to run in NASA TT5... when I stumbled upon the fact that the SCCA switched up their Time Trials Sport classes. The 128i used to be classed into Sport 4, but was dropped down to Sport 5. I'm now giving some thought into changing directions, saving some cash and maybe building for Sport 5... I looked over the "cars to have" in Sport 5 and compiled a short list: 

-E36 & E46 non-M 6 cylinder cars
-Fiat 124 Spider (Lusso/Classica trims)
-Fiesta ST
-All Miata's (specifically the ND2)
-2013-2020 BRZ/FRS

https://timetrials.scca.com/pages/sport-category

Unless there's some other vehicle thought to be a contender? 

Of the above listed cars, I feel like the best cars to start with are the ND Miata or BRZ/FRS. Am I missing something? 

The Sport rules are pretty restrictive... basically OEM diff (no LSD for the 128i), essentially only common OTS springs/shocks/sway bars (mostly at Tirerack), intake/cat-back/flash tune, 245 wide 200tw tires and cooling mods... and now ALL MacPherson strut cars can run camber plates! 

My first thoughts were that the ND Miata's have the best power/weight ratios, lowest overall weight, double wishbones, etc, so I figured they would be the fastest of the bunch... but last year's SCCA TT Nats showed that the BRZ/FRS cars were outrunning the ND's. I'm assuming aero plays a role here? It should be noted that the BRZ/FRS' at Nats last year seemed to be Solo Spec Coupe cars, so they were allowed to run camber mods (before it became legal for all Mac strut cars this year). 

I digress. I'm not sure how competitive an E82, E36 or E46 would be against the above-listed competition on a restricted ruleset? More specifically the E82. Do you think the BMW's can potentially run with the lightweight Japanese cars? Specifically the E82 vs the ND or BRZ/FRS? 

Thoughts? Experiences? 

I'm not sure it's of any use in your intended application, but I own both a 128i and an ND2 Miata, but both are street cars.

The BMW feels (and is) heavier, but also more clinical. The Miata is more lively, more playful. By the numbers, they are nearly identical in 0-60, power-to-weight, lateral G-loading, etc. I suspect a lot will depend on your preferred driving style.

The E82 compares pretty well with the earlier BMW chassis, so I think you should be able to run pretty well with them. I have no experience with the 86/BRZ, so nothing to add on that front.

In reply to 02Pilot :

My wife used to own an ND1, but unfortunately, we kept it pretty much stock and it never saw any track time. 

On paper, I would assume an ND would run circles around the BRZ/FRS- 400-500 lbs lighter, better weight distribution, double wishbones, better power/weight, much quicker acceleration numbers, etc... but I can't shake the fact that at last year's SCCA Nats the twins were marginally faster than the ND's (twins were in Sport 6 at the time vs the ND being in Sport 5). I can only assume aero is the primary factor bringing their times closer together? 

And I agree, I think the E82 is comparable to E36/46. From what I can tell, the E82 seems to have a more capable chassis and the N52 seems to have a broader torque curve vs the old M-series motors, so my thoughts are the E82 should have a slight advantage over the E36/46... but I don't know how well that translates to the other cars in Sport 5. 

In reply to roninsoldier83 :

The torque curve of the N52 is basically a plateau - you get almost all the torque almost all the time. The chassis is excellent in stock form, and easily upgraded (I don't know what you can and can't do in your preferred class). Can you change control arms for the 1M/M3 stuff?

If aero is a concern, would an ND2 RF be a better choice? Heavier, yes, but enough to be offest by the aero?

I can actually speak to this directly.  I just got back from the SCCA National Tour event at PittRace a few hours ago, where I ran my 128i in Sport 5.  Car has koni yellows, Eibach lowering springs, and camber plates.  Tires were 225 Falken RT660s all around.

Format was three sectors, first was a track sprint on the north course, then the south course, then the full course.  This is my local track, so I have run it multiple times before and was comfortable there.  

I got my butt whooped. 

I understand driver makes a big difference, but it was a bit more surprising than I expected.  

With all that said, don't let that stop you.  Perhaps you've got the secret sauce that I've yet to unlock.  The car is competent on it's own as a track car, and I believe it can be a great car with mods outside the Sport rules, but I'm not sure it's the weapon of choice for S5.

Pic, because why not:

In reply to Puddy46 :

Thank you for sharing! Just curious, what kind of car(s) seem to be the cars to have on the national tour? 
 

And how big is the gap? Would 245 wide tires have made a difference? 

In reply to 02Pilot :

I'm honestly not sure, that was just my hypothesis! I suppose someone more experienced with both the soft top and RF might be able to chime in.

We had 6 cars in class, 3 BRZs, a Fiesta ST, another car that I'm not sure what it was, since it was listed as an NB Miata, (that should be in S6), and myself.  Top 3 were two of the BRZs, then the FiST. 

Wider tires will certainly help, but not enough to make up the difference.  The top 2 BRZs had a 9 second gap over the rest of the group.

In reply to Puddy46 :

Wow, 9 seconds is a substantial gap. Granted, I suppose I don't know what the comparative levels of prep and driver experience are, but that's seemingly uncompetitive. 
 

Note to self: consider sticking with my current course of action and prepping for TT5. 

In reply to roninsoldier83 :

A bit of clarification.  That's 9 seconds combined for all three events (Track Sprint, South Course, and Full Course).

Another competitor with a more modified 128i (coilovers, 245 wide tires, M3 diff and control arms) was about 6 seconds off the fastest BRZ in Sport 5.  With that said, driver makes a ton of difference, but that would put them in a tight battle for 3rd in S5.

Just recently got my 128i.

Interesting to read input here. I was initially going to make it a NASA TT5 car to have a RWD option, to go with my TT5 Integra. 

I plan to do the normal. Coilovers, control arms, LSD, 9" wide wheels etc..

Seems weight and wheel width are the biggest challenges this chassis faces? Weight obviously not so much an issue if wanting to strip the car.

In reply to Blackhalo :

That's funny, I also have a DC2 Integra GS-R. Although my Integra is modified, it's still pretty street friendly and not TT5 prepped. 
 

I used to have a CRX that was time trials prepped (SCCA T5), which left a bad taste in my mouth for FWD cars, but that was likely my fault for not developing it further. 

I'm the guy with the Fiesta ST in Sport 5 and paddock neighbor to Puddy46. That Miata in S5 was the misclassed Max car, so it was just 5 cars in S5 that week: three Twins, my FiST, and Puddy46's 128i.

If you're super competitive, then yeah, perhaps a 128i isn't the right vehicle for S5, but I wouldn't let that dissuade you from running the car. They're fun to drive and reasonably quick (and don't constantly overheat on track like my FiST did). I don't expect a 128i to beat the Twins, but with a good driver it'll stay reasonably close. The Twins are a pretty much perfect balance between cornering and straight line speed; to beat one, you either have to be massively faster in the corners (and with how good street tires are these days, the heavier cars don't necessarily give up that much to light cars like Miatas) or much faster down the straights (and that includes making up whatever deficit you have in corner exit speed!).

If you're willing to put the car into Tuner 4, it'll be competitive. Wider tires and a diff help a lot. A friend of mine took his 128i to 2nd at TT Nats one year and it was basically a full prep STX autocross car.

Also, those time differences in the TT results are sometimes due to luck; if you nail a perfect lap with no traffic during the right time of day, you're gonna blow out someone who got unlucky and had an impaired lap due to traffic, mechanical issues, or track conditions.

Puddy46, you should give yourself more credit. That BMW is a new-to-you car. I've been autocrossing/rallycrossing/tracking my FiST since it was new. Some of those Twins are SSC cars with drivers who can trophy at or even win Solo Nationals. I think you did very well all things considered.

A 128i is simply not going to be as fast or as fun to drive as an equally well prepared and setup FRZ86 or ND. The ND has the edge at lower speeds, and the FRZ86 has the edge at higher speeds. The 128i has no edge.

The FRZ86 has less weight, less drag, and better suspension than the 128i. The ND may have more drag, but has much less weight and much better suspension than the 128i. Weight dominates at low speed, aero dominates at high speed. The 128i dominates nowhere.

Driven5 said:

A 128i is simply not going to be as fast or as fun to drive as an equally well prepared and setup FRZ86 or ND. The ND has the edge at lower speeds, and the FRZ86 has the edge at higher speeds. The 128i has no edge.

The FRZ86 has less weight, less drag, and better suspension than the 128i. The ND may have more drag, but has much less weight and much better suspension than the 128i. Weight dominates at low speed, aero dominates at high speed. The 128i dominates nowhere.

I think this is right, it's good everywhere but it's not great anywhere.

In reply to FE4127153 :

I appreciate the kind words.  Even though both my goals of taking the car home in one piece and having a blast were readily achieved, I'd be lying if I said I wasn't disappointed in my result.  But that's just motivation to come back next time and get better.

The mods that would move me to Tuner 4 would be the logical next steps for the car, so that may just happen.  And those mods would make for more enjoyable HPDE and autocross days, too.

roninsoldier83 said:

In reply to Blackhalo :

That's funny, I also have a DC2 Integra GS-R. Although my Integra is modified, it's still pretty street friendly and not TT5 prepped. 
 

I used to have a CRX that was time trials prepped (SCCA T5), which left a bad taste in my mouth for FWD cars, but that was likely my fault for not developing it further. 

Heh.

Yeah, luckily most the TT5 cars in my region are more street cars. A 128i Being one of them. 

But my K swapped DC2 is full interior with a/c still. 15x9's up front with a stock K20A2, just recently running aero, along with the normal Honda suspension stuff. I drive it 100 miles each way to the track still.

In reply to Puddy46 :

Be careful with the M3 front control arms in 'Tuner' class. The lateral ('lower') arm is spherically jointed, and that would technically be a direct bump to 'Max' class on a strictly legal basis.

Also consider that with the 'Tuner' class power limits, an N51 car would probably make more/better power than an N52 car due to the stock 3-stage intake manifold. Adding the same to an N52 car would also technically get bumped to 'Max' class on a strictly legal basis.

In reply to Blackhalo :

In order to be competitive for me locally in TT5, I would have to be pretty fast. Our local TT5 champion is running an E46 that took 3rd at NASA Nationals last year, coming within a second of 1st. He's fast. I'm not convinced a FWD car could keep up with any of the top cars in TT5 (mostly BMW's and S2000's). I also have a very clean laguna blue 2008 AP2 S2000 I've considered tracking, but with how valuable it's becoming (low miles, no accidents, 10/10 matching VIN's, perfect interior, etc), I can't justify it. I used to autocross the S2000, but I've essentially reverted it back to stock and now just take it out on nice days and occasional date nights with the wife. 

Very nice! I considered tracking my DC2, but if I did, I would stick to TT6, as I'm still running the stock B18C1; which is also what keeps me from tracking it: B18C motors are getting pretty costly and difficult to find these days. I've considered K-swapping it (it's more of a continual thought), but I've invested quite a bit into my B18C1- namely in the form of a fully rebuilt JDM B16B CTR transmission and some rare Comptech parts (Comptech header $$$ and Icebox). I also sourced a set of brand new OEM motor mounts I installed a while back, so the car is as smooth as the day it rolled off the factory line. I tried running some stiffer mounts for a bit and the vibration (specifically at idle) drove me nuts. That's probably my biggest hesitation with K-swapping a street car: I know the only option is running poly motor mounts and my only experiences with poly mounts have been less than stellar. 

I bought my 128i (6-speed manual, Sport package car) for $4800, with the intention of turning it into a track car. She needed some love, but I've since nurtured her back to good health. I figured the car was cheap enough that I wouldn't be as concerned with something happening on track. The fact that N52 engines are also relatively cheap was also a strong selling point. 

A few photos for good measure: 

Driven5 said:

In reply to Puddy46 :

Be careful with the M3 front control arms in 'Tuner' class. The lateral ('lower') arm is spherically jointed, and that would technically be a direct bump to 'Max' class on a strictly legal basis.

Also consider that with the 'Tuner' class power limits, an N51 car would probably make more/better power than an N52 car due to the stock 3-stage intake manifold. Adding the same to an N52 car would also technically get bumped to 'Max' class on a strictly legal basis.

Solid points all around. Thank you for the thoughts and insight! I had completely forgotten that the N51 cars come with the DISA manifolds stock and it's not legal to run them in Tuner 4. I can't imagine the N52's compression bump (10.7:1 vs 10.0:1) would make up for the DISA manifold. I wonder if some of the more competitive national Tuner 4 cars are N51 powered... 

You've also reminded me as to why I wanted to shy away from the SCCA and get back into NASA, namely the rulesets not benefiting the E82. The rules in NASA seem to help equal the playing field for heavier cars like the E82. It just hit me that the SCCA class rules regarding tires (same size for the entire class) would give an advantage to the lighter cars, since weight can't really be removed. The rules in NASA, allowing for wider tires on heavier cars, makes more sense for a car like the E82, as does being able to take out some of the weight to level the playing field. Yeah, the more I think about it, the more I'm convinced to stick with my original plan and just build the car for TT5. Thanks again! 

In reply to roninsoldier83 :

Hell yeah man. I paid $8000 for my 128i a couple of months ago. It's really clean and has 120k miles. Yeah, that s2k would be to clean to track for me as well. 

We had an out of region TT5 Miata that's going to nationals, run in our group last month, and he was a good 4 seconds quicker than me, and 3 seconds quicker than our local s2k . He ran a 2:10 and set the track record. Rest of us were in the 2:13-2:16s range. 

But it was a fully caged and stripped car. The rest of our group is full interior and a/c. "Street cars" essentially. So it works out well for now. And there's a good chance for tires every month.

I think the DC2 can hang with the s2ks and other rwds. They seem to be competitive in gridlife. I'm going to try and run 17x10s up front next season, and switch up to a clutch LSD.

I sold my bone stock GSR swap for a good penny, made going with the K swap almost a no brainer. And replacements are so cheap(like the n52). 

roninsoldier83 said:

Driven5 said:

In reply to Puddy46 :

Be careful with the M3 front control arms in 'Tuner' class. The lateral ('lower') arm is spherically jointed, and that would technically be a direct bump to 'Max' class on a strictly legal basis.

Also consider that with the 'Tuner' class power limits, an N51 car would probably make more/better power than an N52 car due to the stock 3-stage intake manifold. Adding the same to an N52 car would also technically get bumped to 'Max' class on a strictly legal basis.

Solid points all around. Thank you for the thoughts and insight! I had completely forgotten that the N51 cars come with the DISA manifolds stock and it's not legal to run them in Tuner 4. I can't imagine the N52's compression bump (10.7:1 vs 10.0:1) would make up for the DISA manifold. I wonder if some of the more competitive national Tuner 4 cars are N51 powered... 

You've also reminded me as to why I wanted to shy away from the SCCA and get back into NASA, namely the rulesets not benefiting the E82. The rules in NASA seem to help equal the playing field for heavier cars like the E82. It just hit me that the SCCA class rules regarding tires (same size for the entire class) would give an advantage to the lighter cars, since weight can't really be removed. The rules in NASA, allowing for wider tires on heavier cars, makes more sense for a car like the E82, as does being able to take out some of the weight to level the playing field. Yeah, the more I think about it, the more I'm convinced to stick with my original plan and just build the car for TT5. Thanks again! 

That's the plan with mine. Though a ls swap and TT4 is tempting. An easy, reliable 300 whp with that chassis would be amazing.

The guy that runs a 128i in our TT5 region posts here and has some YouTube videos on his car. It's competitive and I think with aero he'd possibly be the car to beat within the regulars that run in our group.

In reply to Driven5 :

Good call on the lower control arms.  I didn't put two and two together on that.   

To be honest power isn't where I'd be putting my money first (personal opinion, of course). I actually like how the engine currently sits.  

In reply to Blackhalo :

If you managed to find a clean 128i for $8000, that's a solid purchase my friend! Mine was cheap, but it wasn't what I would call "clean" haha! 

I'm curious, what generation Miata showed up for you locally last month? A thought that has been crossing my mind is how competitive I think an NC with a 2.5L swap could be in TT5. I've owned an NC in the past and have owned 2 S2000's; to NC feels similar to the S2000 in terms of rigidity, but 300 lbs lighter and with similar space in the wheel wells. I've wanted to pick up another one for this purpose for a while now. I should have never sold my NC2! 

I did see that the FWD wishbone Honda's have done a solid job keeping up with the S2000's in Gridlife Club TR... but I wasn't sure if that translated to TT5. I was under the impression that the weight reduction rulesets were a bit more restrictive in GL CTR and the FWD cars are simply lighter cars and since everyone in that class is K-swapped, I figured they just had a better power/weight ratio. Maybe I'm wrong? Within the rules of Club TR, I thought it would be tough to lose much weight out of an S2000. There's some weight in the exhaust and the convertible top (although I thought it would be close to a break-even with a hardtop), but the seats are fairly light stock, the aluminum hoods are super light, etc. While the DC2's are only about ~200 lbs lighter than the S2000, the early hatches have a massive advantage (anywhere from 500-800 lbs for an EG or EK). 

I love my S2000, but I've always thought they were heavier than they should be. Honestly, they don't give up much interior space to an NC, which is how light I thought they should be (roughly 300 lbs lighter). 

As of the last time I reached out to K-Miata, they were still developing a K-swap kit for the NC... once a K-swap kit is released for the NC, it'll be interesting to see how some of these class get mixed up a bit. 

In reply to roninsoldier83 :

I haven't fully looked into the Gridlife rules, but Club TR and GLTC are littered with FWD double wishbone Hondas. Seems they can be completive either way, but the cookie cutter car/tire seems to change all the time with rule changes.

So far my Integra seems to be on par with the S2k in my region, and it seems to scale well with TT5 and it's current rules. 

Think it was a NB Miata running in the Rocky Mountain Region(I want to say he was from Nebraska). Quick car for sure though, he set the track record the first session in July. He'd have gone an easy two seconds quicker had it been in March.

A K swapped NC does sound nice... and yeah, it's surprising how heavy S2ks are.