Tam very 'crashy' after Nitrons fitted!

[chris watton]

jpp said:

Chris

I'd agree. I live about 2 miles from Shelsley and drive those roads all the time (v lucky, I know) and also run Toyos at the front.

My T350 on the original shocks took a lot of steering and power correction around there - lots of tram lining, bump steer and crashing (much more than my old Bilsteined Elise).

Power fitted and set up Gaz Pro Golds on mine last week. They kept the original ride height (avoids grounding for me) so all that has been changed is the geometry, damping and springs. The car is now much much more stable around there, so whilst it's bumpy I am no longer being thrown around or being pummelled.

I experimented with hardening off by 2 clicks and some crashiness returned.So, if softening the Nitrons off doesn't work I would be surprised, assuming your ride height is not causing you to ground or hit the stops (?), you've checked the tyre pressures and you don't mention tram lining.

The only other advice I was given was that if the fronts are set on the hard side of the adjustment range, softening the rear eventually can introduce 'crashiness' again. So perhaps start your fettling from the mid point at the rear? I avoided my first choice of the Bilsteins with Tuscan 2 rear rated Eibachs because the cost was up there with Nitrons (which I don't do enough track work to justify).

I didn't experience tramlining - I did with my first Tam and have it with our MGF Trophy 160 (with Bilstein racing shocks and everything polybushed) - I put that down more to the directional tyres (the 'V' grooved ones) fitted to both cars. (Toyo proxy directional for the Tam and Goodyear Eagle F1 GDS02 for the MG)

Tyre pressures are fine now, I checked them yesterday, and then did another 30 mile round trip to pick up step son from work in the Tam. Hard to tell if there was a difference, but the roads aren't nearly as bad here than they are on the Worcestershire B-Roads - but saying that, it is even slightly jarring driving over painted lines on the road at the moment.

I am surprised by this, as I was under the impression that the Nitrons were worth double what the Gaz shocks sell for, for both ride comfort and handling. I can only assume that what people meant was that, if you use the Nitrons for track days only, on completely smooth roads/tracks, they are great - but for the UK roads in 2014, I'm not so sure. The 12 year old originals I replaced seemed more compliant, at the moment, at least, until I can the Nitrons sets up for mainly road, rather than glass-smooth track.

I don't think I shall ever go down the polybush route for the Tam, too - I can only imagine the ride equating to driving with 4 solid steel bars at each corner, rather than springs and dampers....

[anonymous-user]

Chris,
Did you get new springs with the shocks, and if so were they uprated?

24 front and rear is where I would want to be with my tyre pressures (hot settings not cold).

I run standard Billsteins on our road car, introns on my race car. Very happy with both.

Personally, I see little benefit in adjustable bump/rebound on a road car unless it's going to get on track frequently but I'm sure that yours will be 100% better after set-up. I would leave it a few weeks before doing it if you have new springs.

[chris watton]

TVRMs said:

Chris,
Did you get new springs with the shocks, and if so were they uprated?

24 front and rear is where I would want to be with my tyre pressures (hot settings not cold).

I run standard Billsteins on our road car, introns on my race car. Very happy with both.

Personally, I see little benefit in adjustable bump/rebound on a road car unless it's going to get on track frequently but I'm sure that yours will be 100% better after set-up. I would leave it a few weeks before doing it if you have new springs.

Yes, the springs came with the shocks - this was the package:

[citizen smith]

Hi,

It sounds to me as though your spring rates are far too high (check out what the standard spring rates are), my Chim had them on and I found that with the 225lbs on rear and 325lbs on the front plus 6 clicks the car ran very smoothly on various road type surfaces (ploughed up country roads in Northamptonshire with loads of POTHOLES).

Stiff springs are great for the Track, but no good for the road. If you go over the RUMBLE STRIPS near a Junction and it shakes the car to pieces then your suspension is to firm.

But this is an OLD MANS point of view and I am probably totally wrong.

[m4tti]

chris watton said:

Yes, the springs came with the shocks - this was the package:

Who supplied them to you? Do you know what the spring rates are>

[SergSC]

ChrisPap said:

I got my Nitrons dynoed on a proper damper dyno rig.

This was when they were 2 weeks old because I was shocked by the ride.

They were tested every 4 clicks from soft up to 16 clicks hard. for good dampers all the lines should be pretty smooth transitions. As you can see, the damping control on rebound is pretty atrocious. Where the lines are curling back on themselves and moving erratically indicates that the rebound control is terrible.




I went to Nitron and showed them the graphs I have, and got the equivalent of a shrug. If I'd paid to have them taken back off the car and re-fit, then they would have got around to dyno-ing them to check my results in around 'two weeks'. They promised to send me the build graphs from my dampers and other ino that never turned up.

I resolved not to waste any more money and get the job done right once I'd recovered!

I have not noticed any odd movements with mine, thought I have the 46mm's if that makes a difference, but I'm defo not a damper dyno by any stretch... I can only say it stays totally on course going over bumps, unlike the setup, though the geo setup probably had a lot if not everything to do with that improvement... its just not comfortable.

Not that I know what a good graph should look like but that does look very messy! I totally get your frustration about perceived quality and what you actually got, and even more so about the service you got thereafter, its not good. Not what is generally expected from the brand.

Perhaps these graphs go some way to explain how/why the uprated shocks/springs (with same spring rates as the nitrons) that I had on my s2000 felt far more compliant than this.
I'll be waiting on your recovery and probably following suit

[sascha]

with 225/40-18 at the front i use 1.7bar/cold (psi 24.65646) tyre-pressure on all 4.

my nitrons became "softer" after one week ..

[chris watton]

m4tti said:

Who supplied them to you? Do you know what the spring rates are>

Racetech Direct - Spring rates are - fronts 400 and rear 325 Nitron own made

http://www.racetechdirect.co.uk/tvr-car-part-ntctv...

[Geoff Ashcroft]

I had Nitrons but with Eibach springs through TVR Power a few years back and it was money well spent. I'll look out the spring rates to compare (though they are different makes of spring), but its a joy to drive.

[citizen smith]

Sounds like the fronts are way to hard, the Tam is light car. When I had Racing Reds fitted to a Griff that I once owned, the Fronts were 400lbs and the Rears were 325lbs, the rumble strip problem made the bonnet shake even when the dampers set to a very low setting and stiffening up the dampers made it a nightmare. Personally I would contact Nitron and ask them for suggested spring rates as per originals, unless you want to use the car on a TRACK.

British roads are absolute rubbish, hence European cars are softened up to cope with the rough road surfaces.

[slimtater]

chris watton said:

Racetech Direct - Spring rates are - fronts 400 and rear 325 Nitron own made

http://www.racetechdirect.co.uk/tvr-car-part-ntctv...

Interesting that Power list two types of kit.

One that refers to the Tamora:
http://www.powersperformance.co.uk/store/slug/nitr...

And one that doesn't:
http://www.powersperformance.co.uk/store/slug/nitr...

May be a coincidence but clearly there are a variety of kits out there that may/may not give similar results?

[Sevenman]

chris watton said:

We drove to the Shelsley Walsh Hillclimb breakfast club today (although we arrived very late..), and the drive there was mainly B-Roads, not very good roads at that.

The car was very 'skittish' on these poor roads, and very crashy, it was horrible! It is the first time I have ever NOT enjoyed a drive in the Tamora.

I am there for most breakfast clubs and there has never been a second Tam, shame I missed it. Yesterday I was timing at the Curburgring so the TVR didn't get a run.

Link to last month's trip report.

I drive in from Herefordshire and have no problems making brisk progress. There are some bad roads around, but the ones on the way to Shelsley are ok.

The car is on Gaz Gold Pro with 400 lb/in front and 375 rear springs. I upped the rear from 325 as I found that too soft. All set-up by Neil Garner who did a grand job and the ride has since been complemented by the chaps at TVR Power when they were servicing the car.

I also have Toyo T1-Sport all round, 225/35 on the front. No problems with these, but am careful when near curbs.

225/40 is an option, but may need a > 1 cm suspension lift to keep the clearance inside the arch. Given it will already be 1 cm higher due to the increased sidewall height, that could be a total of 2cm up on the front (good for avoiding grounding the splitter) but you may need to get rear ride height raised to keep suitable rake and then have geo checked. I am a big fan of suitable ride height to allow suspension to do its work, and my Tam has gone up in stages since I bought it.

I may try 225/40 at some point, but not until the current tyres wear out (or more likely get changed due to age given current progress).

[chris watton]

Sevenman said:

I am there for most breakfast clubs and there has never been a second Tam, shame I missed it. Yesterday I was timing at the Curburgring so the TVR didn't get a run.

Link to last month's trip report.

I drive in from Herefordshire and have no problems making brisk progress. There are some bad roads around, but the ones on the way to Shelsley are ok.

The car is on Gaz Gold Pro with 400 lb/in front and 375 rear springs. I upped the rear from 325 as I found that too soft. All set-up by Neil Garner who did a grand job and the ride has since been complemented by the chaps at TVR Power when they were servicing the car.

I also have Toyo T1-Sport all round, 225/35 on the front. No problems with these, but am careful when near curbs.

225/40 is an option, but may need a > 1 cm suspension lift to keep the clearance inside the arch. Given it will already be 1 cm higher due to the increased sidewall height, that could be a total of 2cm up on the front (good for avoiding grounding the splitter) but you may need to get rear ride height raised to keep suitable rake and then have geo checked. I am a big fan of suitable ride height to allow suspension to do its work, and my Tam has gone up in stages since I bought it.

I may try 225/40 at some point, but not until the current tyres wear out (or more likely get changed due to age given current progress).

We (me and my wife) really enjoyed the venue when we were there - it was great seeing so many other fantastic cars, and not just TVR's (wife has a hankering to restore an old mini, and loved looking at the dozen or so there yesterday). Will definitely go again.

Planning to do a road trip to Italy next year, so need the suspension sorted before then, and having the suspension slightly higher may be better for such a trip, too.

Anyway, am out of Tam funds now until my tax bill is paid....

[TVRWazzock]

Geoff Ashcroft said:

I had Nitrons but with Eibach springs through TVR Power a few years back and it was money well spent. I'll look out the spring rates to compare (though they are different makes of spring), but its a joy to drive.

I had Nitrons with Eibach springs fitted to my Tamora in 2007 and have never looked back. Really comfortable drive. I got Colin in TVRSSW down in wellington to set them up for me. Top bloke

BTW I have Toyo's 225/35R18 87y Proxes T1-Sport on the front spiders, anything bigger and the front wheels rub on the top of the wheel arches when cornering hard. I experienced this on the track

[phazed]

I have a set of the new Nitron 46mm Pros on my chim.

Absolutely awful experience.

Returned three times because of faults.
Finally another new set supplied.
Drives superb on track but for the road can be adjusted from "completely bone jarring" down to "very harsh " ride!

I feel the quality of damping leaves a lot to be desired.

I run 500/400 springs and by comparison my other set of Gaz Monos on 450/400 springs run beautifully.

That's not to say Gaz are perfect as these had to be returned after they effed up the damping after a service.

BTW, when the Nitrons failed within 2 weeks they said it would be a month to sort them out FFS!

After a few months of the mad teeth clenching experience above, I feel like a damper test pilot

[Sevenman]

chris watton said:

Planning to do a road trip to Italy next year, so need the suspension sorted before then, and having the suspension slightly higher may be better for such a trip, too.

Anyway, am out of Tam funds now until my tax bill is paid....

We took the Tam on a 3 week European trip back in 2012, it did very well.

Link here if interested. Italian bits are on pages 2 / 3.

Just get Neil Garner to set it up and you will be fine.

[Targarama]

jesfirth said:

Chris, nitrons are excellent shocks and have good adjustment. It sounds as though the damping settings are just too high. Just set the shocks a couple of clicks softer and try it again. If it's still too hard try another couple of clicks. It will only take you five minutes to do and you can get it perfect for you. If you want to go back to basics just set each shock at full soft and work up form there. For normal road use I would guess at say 8 from soft front and 6 from soft rear would work well but it does depend on the spring rates. Don't go back to standard shocks. Nitrons are far superior and once they are set up right will be good. Jes

Edited by jesfirth on Sunday 15th June 19:03

This is the setting mine are on. I run Eibach springs but I'm sure they're not that different. Any more clicks 'harder' makes the ride less competent. Any softer made the rear feel a bit 'washy'. Mine feels like the perfect compromise now and I never think it is too stiff or crashy.

[ShiDevil]

I use Protech Double Adjustable 600 Series Shocks, setup by Centre of Gravity. I've driven another T350 recently on Nitron's and the difference was enormous. I just couldn't safely drive at the speeds in the other car. All about the setup from ride height onwards. I have 400 front and 350 Rear. Rebound and Bump is setup for fast road, although I can adjust the bump for track or country road driving if needed in under a minute, clicks back or forward.

Here's a side photo of the car. The first thing you will notice is the ride height is higher than many T350's, but has improved the performance. As I have mentioned before, it's common knowledge that lots of TVR's went to dealers who then dropped the ride height to make it look better.

[slimtater]

As ShiDevil says, a lot are too low. Here is mine which runs on Ohlin 3-way and also previously set up by CoG:



Another issue aside from the crashy ride is that you can get fouling on the drive-shaft outer gaiter if too low.

[MPoxon]

This is why I went for new OEM spec Bilstiens on mine.