Hi All I know there are various threads about alleged 348 high speed stability and or snap oversteer but just want some thoughts from owners? I have just got a '93 TS (with the battery in front wing) which has Toyo Proxes T1-R tyres with good and similar tread all round. The car is low miles and feels taught when driving. To date I've only done a few runs out totalling less than 350 miles, so its early days. However, I do get the sensation that I've got a lot of weight behind me and don't feel confident in taking much speed into bends, adopting the 'brake heavily in a straight line' principle before and twisty bits. I feel otherwise the back end is going to disappear into the scenery! As a little background I've done track days in Catherhams and also own a Lotus Elise. I know the Elise is a totally different animal but the confidence that car gives you and its cornering speed is immense. I don't feel I could commit with the 348 to 70% or less of the speed I could corner in the Elise. Is this the normal 'feel' in a 348 or does it sound unusual? What are the best mods to improve the handling and feel?
Rear ride height is used to adjust the oversteer/understeer relationship. up means more oversteer. Front ride height is used to adjust high speed braking stability. Up means more HS Brake stability.
T1R's are not that great of a performance tire IMO. They might last a while, preform better than most tires out there but overall, I prefer a softer tire. T1R's are 280 treadwear. Lower the number = stickier (usually), but it can vary from tire manufacturer and model of tire. Start with adjusting tire pressures and alignment. Those two things can go a long long way. Congrats on the TS!
The rear of my 348 had a bit of a shimmy at high cornering speeds on country roads. But even so, it was quite benign - the rear would squirm a bit but then quickly take a set. So you got a warning. It wasn't never a huge oversteer moment. I think some of the good practices for are: - Take it easy till the tires warm up - 348s are firmly sprung and are sensitive to road surface changes, be observant - During the corner, breathe on the gas pedal. No sudden moves like jumping on the brakes, throttle, throw in lots of steering angle, etc. - If you get a shimmy, then you are close to the limits, be careful when pushing further The folks above already mentioned ride height, tires and alignment - you need to make sure they are correctly set. My car was set up probably for the track by the previous owner, it had a lot more camber than some of my friend's cars - it made it very stable on the track but a bit skittish on wet and undulating roads. The late model 348s had a 25mm wider track to help stabilize the rear. Given your's is a '93, it should be already done. Otherwise a set of spacers will definitely help.
Specialé and later 348s had the upper rear A-Arm chasis-pick-up-point relocated downward--which raises the rear roll axis. There used to be a jig circulating around to precisely locate new pick-up points. I don't remember about a change in track.
Car in work shop at present so can't tell you how old the tyres are. Some chap on another forum posted: The suspension bushes / shocks are probably the best part of over 20 years old. Replace the heavy 348 rims with 355 wheels & new tyres, 25mm rear spacers, 15mm front spacers. New suspension / wishbone bushes throughout. New shocks all round, drop the ride height by 18mm helped mine and then get the car correctly shimmed / set up. It will still be nervous, but a whole lot better. Am concerned that after all these mods he still feels his 348 is 'nervous'.... A little confused over this wider rear track. I've read that all cars over the entire production run had the same rear track width to the hubs and that any additional width was created by wheel offset, not actual suspension components? Also that '93 cars onwards had the wider track rear wheels. Any comments about this?
The 25mm was provided through an adjustment of the wheel offset. If I am not mistaken, the stock wheel has the dimensions and offset information on the inner face. Have a look at it - it should be +68mm with the old style wheels and +43mm with the newer style. I'll Plugz, Ernie and the more knowledgeable guys confirm that.
The first thing I would do is check this. Made a world of difference to my car and quite a few others that I am aware experienced similar "nervousness" 😊
Swap out the wheels for 355 18 inchers, get spacers from Ricambi and rear lug bolts then finally some nice modern rubber. Forget messing with the suspension unless you race. Do get an alignment. Vastly improves the car. All spiders and SS cars have the wider rear wheels. I replaced mine anyway.
I have 18" Challenge Wheels, Vredestein Ultrac Sessanta boots and I cannot remember having a nervous or twitchy feeling. I don't drive it like I stole it much, but have done a hill climb and some track time with no issues or concern about pressing hard. Better for you to feel something on the limit rather than nothing until you hit a hedge! I think tyre pressures can make a big difference - especially on a setup sensitive car. Have a tweak around - see what pressures others are running... Check they are at recommended pressures first to get a benchmark...
Well you can see me here with a bit of snap oversteer on a corner that tightens up towards the end, even left foot braking didnt manage to save this one. https://www.youtube.com/watch?v=wrH4KDKmFCE I dont think you ever sort this issue even with best sorted 348s but cat like reactions help. Richard Priors record breaking run at Bouley bay a few years ago shows how to handle it. check this out about 1 min in. There is a spectator shot of this as well I'll try to find. https://www.youtube.com/watch?v=2rgre5_rYg4
Found it https://www.youtube.com/watch?v=SGb7iPgTevM this car was well set up with challenge front springs.
This is not what the car was criticized for. That is not snap anything. That is someone getting too hot into the corner and using the throttle to correct. These cars are pretty tightly balanced and when you lose the fine edge it can bite you. However, less air pressure and wider tires get you a wider margin for error. I push my car quite often and I have never experienced what these videos show once my wheels and tires were upgraded. I have never seen this among the differnt 348's on any of our canyon runs. The issue with the car has to do with high speed instability. If you have ever witnessed the oscillation of death at 120 you know what I mean. Stock front tires are too small and the non SS cars don't have the lower lip spoiler. Aero management and better wheels/rubber cure this. Keep your pressure below 35 lbs. Drop to 30-32 if you are going to cook the corners. Plugz uses 29 lbs, I think he said. This car is excellently balanced as long as you stay in the performance envelope and use your throttle appropriately.
My 1990 348 with stock wheels and older tires was tail happy when going over 75 mph... Changed my wheels to 360 wheels, replaced my tires with Bridgestone S-04, set tire pressures to 30 psi. Now, I can confidently going well over 90 mph. Cornering is also much better.
Do you run spacers with these wheels and what size are the tyres? Do you know if these tyres are still available? Also what pressures are you running. Have spoken to Hills Engineering and they said all 348's across the entire production had the same suspension track width. It was only the late US spiders that went from the factory with wheels providing an additional 50mm track width due to wheel offset. Apparently no European/UK cars came from the factory with these wheels.
I drive my 348 hard, ask the FOG guys and I can keep up through the turns but get lost on the straight runs due to lack of hp. I have the challenge wheels, the car lowered and 4 corner balanced, running 235 in the front and 295 in the rear. Very confidence inspiring through high g turns. But, but when i first got the car and it wasn't set up right it was very twitchy and understeered tremendous and just didn't feel right at the seat of the pants. Get it set up right and it's golden. Kai
