My Losi Pro SE Racer Project

[jaro]

MY next project will be a Pro SE, which I picked up along with a few bits from someone on this group, thank you Cedric.

The car has been put together from new parts and most the work has been done for me already. It's almost seems a shame to do it, but the plan is to race this over the Summer months. I will be doing a few changes so the car is more like what I raced towards the end, including the fitting of a Retrofit gearbox.

Will update more as the project progresses.

Also bought a TBG body and a set of decals from Canada for the car.

[LosiXXkid]

Excellent! What wheels are those you have fitted there? Are they old Pro-Line's?

[jaro]

The rears are Proline which are very nice, whilst the fronts are a pair of B4 ones I had to hand. Unsure which direction to go with the wheels yet, but I guess it would makes sense to do the same as my JRX2.

[jaro]

Just built a new Retrofit gearbox for my SE, plan is to get it as near to the car I had back in the day. I do plan to race it though, so I think subtle changes will be made over time.

I also have enough parts to convert it to 2.61 if required, but was unsure which would be better so stuck with 2.19 for now, I'll probably be using an 8.5T motor.

Decided to fit a dual slipper from the offset as it should be easier on the gearbox, have an 87t spur on order which should be nearer the 88t supplied. Was also wondering weather to fit the VTS slipper, should be possible, may try the one from my modern racer, would their be an advantage?

And fitted to the car.

[jaro]

After a hand injury which made it unable or wanting to do anything for the past 3 months, I finally got last week to do some work ready for racing. Car was totally stripped and rebuilt with a few changes along the way. A few pictures of progress.

Ballraced steering levers and servo posts fitted.

Rear bulkhead modified to allow lipo stick packs.

Its not pretty but its adds a little protection.

And some front end protection with a new bumper.

Topshaft drilled, tapped and shortened to accept AE v2 slipper.

[jaro]

Car ready for yesterdays racing.

[uniquenamehere]

Looks great! Nicely done...

[bearrickster]

very nice, I also still race my se when I have a place to race it. I like your mods, I did a few more I used the cheaper and easer to get XX 8008 body so I drilled and mounted XXX wing mounts. and used a puretech velcro strap on my Lipo but I didnt have to cut the bulk head. I just left the stock battery holder out all together. very nice car. please post how you dowith it. Mine held its own against modern B4's with no problems at all. it didnt turn as well but was much faster down the straights then they were.

[jaro]

Raced car Sunday and wasn't bad for first run, not up with my RC10 yet but that has had a lot of track time and now just works everytime I put it on the track. I can certainly see some more potential from the SE and should be as good or an even better car. We race on high grip astroturf tracks and the biggest problem I had was turning into high speed corners. The front end was to soft and would just dig in, lifting the rear wheel everytime. I played with different oil and spring rates all day to no avail, the front end was just to soft. If I could overcome this then I think the SE could be a very good car.

As to the racing itself a few teething problems throughout the day, with me only managing to finish two qualifying runs. Just managing to qualify 8th in the A final and finishing 8th.

[bearrickster]

Turning is the big issue with mine also. I found tires made a lot biger different onthe front than anything else. I went through 10 different front tires at the Vonats trying to find something to work. and changeing oil and springs did nothing

[DerbyDan]

Whao! This has turned out really nice! (Been watching your build-up of this last week on the Iconic.RC facebook page)

I've got to get myself over to the Kidderminster track sometime soon & have a go at racing with you guys in the vintage class... it was one of my favourite tracks Bitd & I scored my best ever result at a 2wd national meeting there (C final I think?)

Regarding the front end diving in - I ended up running the front of my JRX2 quite soft & with added weight on the nose just to get the car to turn-in (even on Astro) - understandable given the amount of rear end bite that is provided by the 5-link set-up. The Pro SE runs swept wishbones with the more traditional 'H'-arm rear end... which I wonder might be adding to the excessive front end bite that you are describing?

[jaro]

Yes didn't get chance to run different tyres, used Schumacher 2 row studs all day which is a pretty neutral tyre. On the high bite astroturf I had no lack of turn in, infact I had too much and I had the steering rate turned well down. Their was some on power understeer as to be expected but no worse than any other rear motor car. Will have to play with tyres next time I get chance to practice, perhaps a Proline rib would be a safer bet. I think as Dan mentioned the SE swept front wishbone isn't helping, it does do some strange things to front wheels through their travel. Ideally though a shock hole further out on the wishbone would be the answer, the outer hole at the moment is far to inboard making any leverage very soft.

Dan you'll have to get yourself over to Kidderminster, still early days but we managed 2 full heats of competitive fun racing. Just some of the variety on show.

[alien3t]

with running the associated slipper? why the cut down re-thread to make fit. was the shaft way long cause of hydra drive?

Thought maybe losi 22 slipper, (what im thinking just for the using losi on losi) since the 22 slipper works on xxx, which works on xx and so on?

[DerbyDan]

Love the Wild-One... somewhat out-gunned in this company!

The photos look great - certainly gets me all excited seeing these cars in action, for me having an old RC car sitting as a display peice on a shelf is like viewing a car or plane etc in a museum... getting them up & running & even racing them really brings this hobby alive, the added dedication required to make adaptations to run modern equipment, gathering spares etc all adds to the interest.

Regarding tyres - did you try the stagger ribs? As you say the two rows are quite 'neutral' but what I find with the stagger ribs is that despite giving quite a bit of front end grip they don't 'catch' or 'bite' if you land a little a squew-wiff off a ramp ot undulation... there's a little initial 'give' to them which really helps.

[Jirka]

To handling problems: Try to limit shocks down travel on both front and rear by adding some spacers between piston and cartridge. Also use the most outside locations for shocks in arms also on front and rear. On front use most inner top shock mounting hole: even this makes the front end more soft, it also makes the car steer smoother and more "rounder" if there are tracktion differences in corners. Try to use even more heavy front springs than Losi's blue. Losi have black front springs even those are not periodic correct or then some heavy springs from other brands. Using toe out in front will decrease high speed steering a little and increase low speed steering, but this is rather fine tuning than correcting major handling problems.

I even used blue and green rear spings on front when I drove indoors on 1:12 tracks with foam tires. Naturally the front suspension with rear springs was really hard since they have much more preload, but handling was much better than with front springs. If You use rear springs on front, You should really tune the front shocks down travel property, since maximum rebound = front ride hight.

Hope to see more racing pictures from Your SE!

Jirka

EDIT: And about tires: Try to find either stagger ribs as already recommended or then just Losi's ribs that worked always at least good if they were not the best tires, but never bad.