savagete2860

I appreciate everyone indulging me. I am 100% over thinking all of this, to the point of analysis-paralysis probably. At the end of the day, I just want the smallest enclosed trailer that can fit my Caterham, its weather gear, aeroscreen, and a spare set of wheels. This thread has helped me understand that a 7x12 or 7x14 would probably work for my use, and looking around that should put me at a weight that is close to 3000lbs, give or take a bit going the aluminum route. @Vovchandr has been saying 5k lbs tow limit or more for a vehicle, and that seems to add up with what others have been saying, so I think I need to look at a midsize truck vs a "trucklette" like the Maverick, unless I 180 and go for an open trailer. I will continue to ponder... still open to more suggestions, comments or advice.

Good stuff @Timothy Keith-Lucas appreciate the photos. Guessing you pull the cars all the way to the front? I like the winch idea too. @bball7754 your trailer is awesome. I might have to at least try and get an estimate for something similar from them to compare to a standard enclosed trailer. @Davemk1 I 100% agree with everything you said and appreciate your anecdote. Tongue weight in the safe rage is a must for me - especially being new to towing. Your situation with needing to add things in front to hit 12% tongue weight make me a little worried about a v nose enclosed trailer where the car will probably be further rearward compared to an open trailer. @Vovchandr In your trailer photos your car looks pretty forward as well - have you ever measured your tongue weight? Are you able to hit 10%+ tongue weigh just by pushing the car forward?

What is not comfortable for long distances? Sway? Acceleration/braking? I think your setup is closest to what I will likely end up with, so if you're saying it kind of sketchy feeling for longer hauls I need to take that into consideration. Does your trailer have brakes? Any idea on weight? I'd love a picture when you are able to its not too much to ask. Like you said, a seven is almost 11ft, which only gives a hair over 1ft to move the car to adjust tongue weight. The reason I was asking about the V nose is that it will push the car back further than a non-vnose trailer, i think. I don't know if that is good or bad relating to tongue weight. A 14' obviously gives your more room to move backwards if needed, but would have the same problem moving forward V nose vs flat.

Again, I appreciate everyone comments. I have some good advice here. Tire ratings are on my list now of things to check. It might not make financial sense in the near or medium term, but time spent dealing with uhaul every track event and hauling around a questionable trailer doesn't seem worth it to me. I get people do this all the time, but it just seems like it would be a lot less stressful if it was my own trailer. I think that peace of mind is probably worth the financial trade off. Also, the biggest piece is I still like the idea of enclosed over open. I am confident a 7x14 enclosed would fit a 7 no issues. @Timothy Keith-Lucas you mentioned you are towing a 7x12 enclosed, how much left over room is there with your 7 loaded up? Is it a V nose? If you had to get a new trailer, would you buy that same size again if it was specific to your 7? How are you securing in your 7? Pictures here or in the thread @Vovchandr started (thank you, btw) would be super useful for me just to see as well if you had any. 7x12 sounds ideal but I want to make sure I am not going to be handicapping myself. I have been looking around on a few sites at trailers. Looking at https://www.stealthtrailers.com/enclosed-7-wide-cargo-trailers, it looks like bare bones aluminum v nose tandem axle 7x14s trailers can come in around 14-1500 lbs. Same setup in 7x12 are 1-200lbs less. I haven't weighed my car, but allegedly it is 1235lbs without doors or roof and 5 gallons of fuel. So I am assuming 1300lbs for car weight that puts me at anywhere from 2600-2800lbs. Throw on trailer brakes (no idea on weight of this stuff) and the actual straps (again, no real idea on weight here), etc, would a safe estimate be 3000lbs enclosed? I think so but I want to make sure there is nothing I am totally missing here. Is anyone here paying attention to tongue weight? Being new to towing, reading about sway I want to make sure whatever I get I can put in that 10-15% range. I am wondering if I can even get to 10% tongue weight if I go with a smaller enclosed trailer with a v nose with just the car loaded up. Anyways, assuming my assumptions are right, or at least in the ball park, towing load should be about 2800-3200lbs with a tongue weight of 280-320lbs (10%) to 420-480lbs (15%). Does that seems reasonable for any vehicle with a tow rating of 4k, electronic brakes, and also assuming payload can handle the tongue weight, passengers, tools, and a spare set of wheel/tires?

Thank you for the replies everyone, super useful stuff. I am still searching around for both trailer and truck. That was a good call out for checking the door width on 6x12s, a lot (all of the ones I was looking at) wouldn't fit my car. I am sold on tandem axles, it just seems worth the added safety and stability. Also I didn't call it out but I was planning on brakes on whatever trailer I get as well. I really REALLY wish those clam shell trailers that are all over the place in the UK were sold over here. I would snag one of those up in a second. I am guessing there isn't really anything comparable in the states, right? I haven't found anything but maybe I haven't looked everywhere. Maybe its worth reaching out to some custom trailer places and seeing if they could build something similar within a reasonable budget. I did some rough measuring, and a mid size truck can fit in my garage along with my 7, only just (door opening might be a problem and not enough height to jack it up for maintenance). I need to try and test it out in real life to see how much of a pain that would be along with the miserable gas mileage. With only doing a few events a year, it might make more sense to get the smaller, more economical vehicle, and deal with the downsides of an open trailer. I'm still pondering it all... I would love to see some more tow setups.

Thanks for the replies. Most of the higher tow capacity SUVs are just as wide as a mid size truck, so really don't think I'd go for those since I would like something with a bed as well for other purposes. Also a P car for a tow vehicle is out of the budget lol. I am still leaning pretty hard towards a maverick, I just need to make sure the trailer options would work with it weight wise. Also just to clarify, the Caterham will still be stored my garage, the trailer will be stored somewhere else. Thats one of the reasonsd I want to stay on the smaller side for the tow vehicle. Sounds like an enclosed 6x12 does fit a Caterham, its just a but of a squeeze. I would be fine with that, I think. I just want to make sure were talking enclosed and not an open trailer. Is that tight on the width side or the length side, or both? Anyone have photos of a seven in an enclosed 6x12 trailer and how its tied down? Lets say I end up with an enclosed trailer, what do I need to look for inside of the trailer? I am not looking for anything fancy other than loading in the car and making it secure. Should tie downs be in a specific, maybe non-standard place? How sketchy is a single axle, really? It looks like the 2nd axle usually adds about 600lbs. Is that worth it for safety? I never really towed anything so maybe I am ignorant but how often are tires really blowing out to cause issues? V nose is a good idea I assume?

I posted this on reddit's r/cartrackdays, but it was suggested to me to ask here as well which seems like a no brainer. My local track, PittRace, is closing and there are no tracks in comfortable driving rage. So I am looking at towing options now. To start, my home is NOT conducive to larger vehicles. I am on a very narrow one lane street and my house has about a 20ft long drive way that is just barely two cars wide and is pretty darn steep (backing a trailer onto my property is likely impossible or at the very least close to it). It leads into a "2" car garage, which really feels more like an over sized 1.5 car garage. My Caterham is currently parked in here along with my 2021 Subaru Crosstrek (tow rating = 1500#s). I generally work from home and share this vehicle with my wife as our daily driver. The tow vehicle will replace this. Given my space constraints and the primary use case, I am looking for something relatively small. The smaller the better with modern niceties of apple car play and heated front seats are top of list. I am looking at a truck at this point vs an SUV/Crossover/etc. Trailer wise, I don't know where yet, but it will need to stay off property. I simply have no where to keep one. My first thought was an aluminum single axle tilt trailer. That would let me get something like a Ford Maverick with the 4k tow package (this was my front runner for a vehicle) and my total payload would only be ~2k lbs. The more I read and look, the more I think I want dual axle for safety and enclosed would be nice on the trips that are further out where the weather might be questionable in route or overnight parking in sketchy parking lots. So what is the smallest size enclosed trailer that can fit an s3 Caterham? I have seen a few 7x14s, but I am wondering if a 6x12 would work? I think even with a 7x14 trailer, I could squeeze in under the Mavericks 4k tow limit, but being enclosed I am not sure how terrifying that would be to drive with the additional surface area on windy days/passing semis blowing me around. If I must, I think I can squeeze into a mid-size truck, but it will BARELY fit in my garage. So what say ye - what's a good truck/trailer combo for my use case?

I think it was a ford fiesta st. Turn 17 was catching a lot of people out that day lol. https://10fsphotography.smugmug.com/Pitt-Race-TNiA-10-15-2025/Novice The car community is totally gutted about this in my region. Shameless plug to push back even if the outcome is likely inevitable: https://savepittrace.org/ PittRace is an AWESOME place. Alan Wilson designed track, exceptional facilities, hosts everything motorsports related, drifting, karting, autocross, car shows, motorcycle racing etc. The owners were putting about $1m each year into the facility since they bought it I think 2010 or so from the original owners. The sale came out of nowhere and speculation is the owners were offered a boat load of money for a fire sale. The same developers supposedly also purchased an RV park and a golf course for a total of 2k acres. If it does become a data center it will likely be largest one in the world. If it can happen to a track that is doing great financially and owned by a couple who loves motorsports and are already extremely well off, you better believe it can happen to your favorite track.

I ended up at the track last week and it went great. Rocky Mountain Caterham sent me out a beefier "race" coil subloom that I ran. I don't know if it was the race subloom, cooler temperatures, or something random I tightened since last time, but the car ran great without any issues. Hopefully whatever the cause was it doesn't pop up again. Aside from just going over the car 100 times the changes were: - Race coil subloom - Newer Ford plugs - Swapped to another (aftermarket) TPS I will post an update if it pops up again, but hopefully this thread slowly gets pushed down never to be surfaced again.

@slowdude Yeah that does sound different than mine. I can drive my car for short or extended periods of time with no issues. I couldn't even give you a description of why I had misfires at the track, it wasn't that hot and after the car cooled down a decent bit it had the same issues on the way home. Then 0 issues at all in 24 hours. I put on about 3k miles on the car in what has realistically been about 2 months, driving it almost every day it is nice outside, and the only time it had a true "this is totally broken" issue was the track day. @KnifeySpoonyWhat year is your build? I am guessing you are on the 9a4 ecu? Are you running with the green or black injectors? How you describe your car is in line with most owners with RBTBs threads I have read (blatchat mostly). Kind of why I was surprised my new car seemingly ran like a hunk of junk until I introduced more air. You mentioned somewhere your car idles at ~1100rpm. I am wondering if you have an older/different tune. I was told the car should idle between 900-1000 RPM and my car in closed loop will always target that. I have seen 1100 before and that when I added even more airflow which is when I first realized that seemed to fix my startup/idle issue. That was also only in open loop, and close loop pulled timing/fuel to bring it back to 9-1000rpm. My 420 is a new car assembled by RMC. Summer 2024 build (first year they started using the newer 9M4 ECU) that I took delivery off in late June of this year. Josh from RMC has been working with me to help troubleshoot the car's issues. Me being located in PA (not at altitude) and them being in CO makes it hard to really do much aside from send parts back and forth. Aside from the initial "sticky throttles" that are now fixed and mystery trackday misfiring that pretty much ruined the first track day, the issues have been tolerable (and now bandaid-able) to where I would rather keep the car in my possession to enjoy for the back half of the year before winter comes. If the car has the same misfire issues again on my next track day I think my only option at that point will be to ship the car back to CO. Related to the idle and start up, below are my throttle adjustments, RPM and STFT evaluated using Easimap. Baseline (hesitation and bogging issues) Throttle opening size: 6mm Airflow Rate: 5kg/hr Air bleed screws open or closed?: closed Cold idle RPM: 4-700 RPM Warm idle RPM: 900-1000RPM STFT correction at warm idle: pegging -20% Adjustment #1 (Started and ran great - maybe a weaker over run feeling and slower rev dropping between gears) Throttle opening size: 7mm Airflow Rate: 7-7.5kg/hr Air bleed screws open or closed?: closed Cold idle RPM: 1000 RPM Warm idle RPM: 900-1000RPM STFT correction at warm idle: +/-5% Adjustment #2 (This is what I am running now.) Throttle opening size: 6mm Airflow Rate: 7kg/hr Air bleed screws open or closed?: open Cold idle RPM: 800-1000 RPM Warm idle RPM: 900-1000RPM STFT correction at warm idle: -12 - -8kg/hr

Grounds seem good, I ended up not replacing the lambda sensor, new plugs, unknown about AFRs since I only have the narrow band. When driving, the car feels fine, pulls fine, etc. I actually think the plugs were likely so dark because of how rich it is/was at idle. I tried a new ECU and the issue remained so not an ECU problem. Is there a way to track fuel pressure in easimap? I don't even know if the car has that data available, i think its all just voltage based from the ECU, right? That is one area I feel like I am in the dark. As I mentioned before, the idle, startup, and tip in off idle issue is completely resolved if I introduce more air at idle, over the recommended settings from Caterham. CC say throttle openings at 6mm and pull 5-6kg/hr. If I pull 7kg/hr on each cylinder either via opening the throttle bodies more or from the air bleed screws, I have no issues at all in those areas. The car simply wants more airflow in that area for some reason. To be honest I am just going to run with it and not worry about it unless I ever hear back from CC that its a huge mistake and the car will explode. The bigger issue is how it acted on track and on the way home, where it would have no power for a decent period of time. I don't know what could cause that other than an electrical issue or something that is/was failing. I do kind of wonder if the pump was acting up. Visually all the connections and everything seem fine, and the car runs like a top on the street noodling around, hard on back roads, and even at autocross. What could even cause something like that which would magically fix itself by the next day with 0 change? I have absolutely no clue.

I think I would like to have this as an option to try. I might be being daft here, would I simply connect the two battery cables here? There are 4 other connectors on the back of the master switch. 2 go to a weird white rectangular box and two go to what I am guessing is the ignition switch (white and purple wires). What you describe sounds like where I am at now with the air bleed screws adjusted but still with 6mm throttle openings. Its slightly annoying driving around town but not awful. It must just be a caterham thing, any other car I have had does not do this. I really think its just a poor tune that is designed to work in almost any condition without concern for running well, especially at startup/idle. Maybe one day I will get a remote tune on the car. Before the throttle adjustments, my car was sketchy pulling out into a high traffic road, especially from a hill, because you never knew if the car was going to bog down or even stall. Autocross launches were very annoying too. Pressing the throttle to raise rpm to ~3-4k RPM would cause a huge hesitation that would clear up after letting off the throttle and getting right back on it making it feel like a song and dance to get off the line.

Thanks for the suggestion @BlakeJ. When you had your issue was the misfire intermittent before fixing? Was it similar to the video I posted? On my car, the cables to the battery are tight and the grounds to the chassis and engine are good. Wires to the alternator and starter seem fine too. I am not ruling out a battery connection issue but I think it would be at or after the master cut off switch. Although I am not sure what is what, the connections on the switch under the dash seem okay. I am not sure how to test and verify that though.

I ended up taking off the RBTBs again to replace all of the o-ring seals. measuring the old o-rings, they were ~50mm ID and 1.8mm CS. I bought a few sizes around this range and ended up using "uxcell Nitrile Rubber O-Rings 52mm OD 48mm ID 2mm Width" that I bought from Amazon. Putting them back on and re-calibrating everything, I started to play with the air bleed valves for the first time. I set the throttle openings to 6mm and slowly cracked open one of the air bleed screws while measuring the air flow rate. This actually INCREASED the the airflow. It makes sense thinking about it and now seeing/hearing it happen, but I was under the impression they would decrease airflow, making my issues worse. Well I adjusted it up to 6kg/hr to stay in the spec recommended by caterham (they say 5-6kg/hr) and the car runs much better than 6mm with the air bleeders fully closed. Still not as nice as it did when the car was adjusted out of spec to 7mm opening and 7kg/hr, but enough that I almost don't notice any of the off idle hesitation issues. Once fully warmed up I am seeing STFT between -15 and -12 which while not ideal is better than pegging -20% and probably wanting to pull more. Still curious if anyone sees any issues with either running the throttle openings slightly more open than spec or at the recommended spec with the bleeders open more. Both set to 6.5-7kg/hr airflow at idle. I think I am calling that issue solved, I don't think there is anything wrong with the car, it just wants more air at idle. The issues I had on my last trackday is now my primary concern. My local track, PittRace, decided to randomly sell in a single day earlier this week. Rumor is for a boat load of money for a datacenter. Really sucks. It is a really awesome and modern track and its going to be a huge loss for the motorsports in my region. So my urgency now comes from having 2 last track days this year - and forever at this track. I really want to be able to drive it for these last times and having the car be undrivable would be a huge disappointment. I have wailed on the 420R on the street and at several autocrosses and it never missed a beat. My first trackday though, the car fell apart. 2nd and 3rd sessions ended with the car cutting power - with not real reason aside from maybe heat. This was at WOT and part throttle, high and low rpm - but mostly with a little bit of load. It also happened on the highway on the drive home aftert he car had some time to cool. The next day the car was totally fine and I have not been able to reproduce since. I am wondering if this is a fuel or ignition issue tied to an electrical gremlin or heat. I have a battery master cut off switch (the CC one) and I have always had a peculiar issue where very seldomly, if the battery switch was off and then flipped back on, the car would crank and never start or even seem like it was trying to. I could crank forever and it would never start. When this happens, flipping the switch off and then back on always fixed the issue and the car would start like normal. I did manage to catch this wile trying to connect easimap - it seemed as if the ECU didn't have power. Not sure if that narrows things down or not for any gurus. Anything else I should check? I feel like I can't do much unless the issue gets worse at least enough to replicate the issue but want to cover any bases that I can. I just don't know where to start.

So even though the track day engine power cut was extreme, the car drove totally fine the following day. I swapped out the plugs which were pretty black. Hoping that was the main cause but I guess I won't know until my next track day. I also have officially ruled out the ECU - tested out a brand new unit with the RBTB tune and same deal. Off idle bogs, stalling and poor idling on cold start - everything was identical on the new loaner ECU. So now what? Well, I tried something silly. Adjusting the idle stop screw so the barrels are open more than 6mm. I opened it to an random size that ended up measuring 7.5 mm and then adjusting the TPS. Results? Car fired up and idled great cold. The idle bogging was also fixed. I could now see instead of pull 20% fuel, it was adding 6% fuel. So I tweaked the opening some more and landed at 7mm. This makes the car drive like I feel it should. Starts up right to 1000RPM cold or hot and I can actually stop on a hill without having to rev the car a few times before touching the clutch. STFT is not anywhere near 20% swings. I know Caterham says to adjust the throttle to 6mm and they should from 5-6kg/hr but my car runs very poorly at that configuration. At 7mm the car is pulling 7kg/hr on each cylinder. Everything looks great at idle and cruising, WOT wouldn't be impacted and feels the same. So uhhh.. good idea/bad idea to keep it like this? What do the people think?