Modern Exotic sport car handling and comfort possible in a s30?

[SHO-Z]

It all depends on what modern suspension you want to graft onto your z. There is a tread on using 240zx rear four link for starters. Some of the BMWs might work along with seats and stuff. All it takes is research, $$$$$ and elbow grease. A few years ago I almost bought a wrecked 944 Porsche and was looking at using the transaxle and fron suspension, waited too long and it was gone. The suspension that the Cobra kit cars looks neat for the front end but fabing the connecting points could be a challange. Strut suspension has come a long way in the last 40 years so look around.

Edited August 30, 2010 by SHO-Z

[johnc]

Maybe we need some clarification on "breaking the bank." If S30 aficionado is willing spending $60K on a new M3 and then complains that you can't get similar world class performance when spending $10K on a S30 then that person is a fool.

 

If you take that same $60K and spend it on a S30 you can get pretty damn close to that M3's level of performance and comfort. One of the keys on reducing the NVH on a S30 is to emulate the concept of a rubber isolated subframe that all modern performance cars have. Isolate the front cross member, TC rod mounts, rear transverse link brakes, front diff cross member, and the strut tops and you've gone a long way to reducing NVH in the car.

[RTz]

Clean/solid E36 M3's can be had for under $15k. E30's under $20. C5's under $25. Might even be a couple older Porsche models that fit in this range as well.

 

Building a 'comparable' S30 for that kind of money is pretty tough.

[ZR8ED]

Some good ideas here. I'd like to see some more discussion regarding some of the "how's" I understand the amount of $ and effort required to do this, because this too has been one of my goals for the last 8 or more years now. It is also a main reason for selling my current Z for a new project Z.

 

John had some excellent suggestions with regards to isolating the subframes/suspensions. Here are some of the things that I started with to make the car more comfortable. (I'll skip most of the history here, and in no particular order)

 

First, I worked for several years to reduce the fumes getting in the cabin. It is much more comfortable when getting out of the car NOT smelling LIKE the car. Seamsealer, new rubber seals, etc (tons of info on what has been done

 

I put in extra insulation (foil backed jute) and placed it in the usual places, as well as tucking it everywhere I could think of, and new carpets.

 

I filled my roll cage (don't want to hear about roll cages on the street..water under the bridge now) with expanding foam. This reduced the "tinniness"/echo's etc. I also added padding to the cage. (tastefully)

 

I put in more comfortable seats (Fiero seats)

 

I rubber insulated the diff mounts to help with cruising..as the rubber takes up, it becomes a solid mount (metal diff strap)

 

I wrapped the first 4ft of my SS exhuast with header wrap, and secured it with SS safety wire. (this helped, and I would like to wrap it further back..lets say to the rear suspension area.)

 

I added some extra insulation around the gear shifter (triple rubber boots)

 

I also have softened the suspension just slightly to make street driving less harsh..The car sees 99.99% street, and .01% track use. I have tokico non adjustables (Illuminas if I recall)

 

 

Going forward, I would have added the thin "sticky sided" insulation (unsure of brand name etc) and I would use it on the inside of the car behind plastic interior panels, and headliner, firewall, wheel wells etc. This way I could shape it to fit tight into corners and around curves.

 

I would also be interested in Johns ideas about suspension isolation..Thin rubber? extra grease to reduce creeks/groans?

 

 

Ok who's next to share?

[johnc]

Clean/solid E36 M3's can be had for under $15k. E30's under $20. C5's under $25. Might even be a couple older Porsche models that fit in this range as well.

 

Building a 'comparable' S30 for that kind of money is pretty tough.

 

An E30 or E36 BMW is not a "modern" sports car. They are 15 to 20+ year old cars. And I'm pretty sure I can build a S30 to be comparable to a non-Z06/non-Z51 C5 Corvette for under $30K.

[RTz]

An E30 or E36 BMW is not a "modern" sports car. They are 15 to 20+ year old cars.

 

 

A cars age isn't one of my criteria. If it performs equal to/better than a Z, is more comfortable, quieter, for similar investment, it's a candidate for consideration.

 

My E36 lacks some tactile qualities. It's somewhat boring to drive, but very capable. I think there is some latitude to trade off some comfort for tact, and still have an easy car to live with. I paid less for it than a typical used modern Honda.

 

My departed E30 was the closest thing to a 240 I've ever driven in terms of feedback and total performance, but it was light years more comfortable, quieter, and refined. It had a bit of suspension work, but nothing that kept me from driving it regularly, or on longer trips. I'm even willing to say it handled better overall than any street-able S30 I've ever driven. I sold that car for $14k. Another $6K or so, would've brought the power to supercar status.

 

 

And I'm pretty sure I can build a S30 to be comparable to a non-Z06/non-Z51 C5 Corvette for under $30K.

 

 

If anybody can, it would be you. I think very few of us could, myself included. Still, $30K is a pretty good chunk and I suspect it's resale value would suffer (more so than the C5 anyway).

 

I'm not arguing just to argue. Honest. I would very much like to own an S30 pleasent enough to daily drive, without strangling it's general charecter, and not feeling like I've invested 1/2 my retirement or life. If there is a path to get there, I'm VERY interested.

[johnc]

If I was going to build one, this would be my initial plan:

 

1975 280Z Chassis - A little stiffer and better corrosion protection then the earlier cars.

Single turbo VG30 engine - Tuned to about 300hp.

Z32 5 speed.

R200 with an OS Giken LSD.

235/45-17 tires on 8" wide rims all around.

Custom valved Bilstien shocks.

2.5" race springs 185F 215R - 12" tall.

Camber plates - rubber insulated.

Hypercoil hydraulic spring perches top and bottom.

Mostly rubber bushings.

Additional rubber or urethane insulation creating a pesudo rubber isolated subframe.

Complete Mazda MX-5 brake system including ABS, computers, MC, booster, wheel speed sensors, etc.

 

Then lots of detail work on interior sound deadening, big rattle elimination effort, new and custom door, window, and hatch sealing, 350Z seats...

[tube80z]

If I was going to build one, this would be my initial plan:

 

1975 280Z Chassis - A little stiffer and better corrosion protection then the earlier cars.

Single turbo VG30 engine - Tuned to about 300hp.

Z32 5 speed.

R200 with an OS Giken LSD.

235/45-17 tires on 8" wide rims all around.

Custom valved Bilstien shocks.

2.5" race springs 185F 215R - 12" tall.

Camber plates - rubber insulated.

Hypercoil hydraulic spring perches top and bottom.

Mostly rubber bushings.

Additional rubber or urethane insulation creating a pesudo rubber isolated subframe.

Complete Mazda MX-5 brake system including ABS, computers, MC, booster, wheel speed sensors, etc.

 

Oddly I had a similar list I was thinking about. I talked to Richard Pare (he invented the hypercoil perches) and he said they offer no advantage on a strut suspension. Were you thinking about them to reduce NVH?

 

I would add a few things. Woodward custom power rack and KRC pump to be able to adjust the steering feel to my liking. An upgraded HVAC system and a decent cruise control. I had a new 1978 280Z with factory air and it doesn't come close the to the system that was in my SER or my Titan. And for NVH I've often wondered if you could put some sand on a bare floor and run the car to see if there were wave patterns that formed (perhaps too low tech).

 

Cary

[johnc]

I talked to Richard Pare (he invented the hypercoil perches) and he said they offer no advantage on a strut suspension. Were you thinking about them to reduce NVH?

 

 

Yes. And in testing on the front of Toby's FP E36 BMW, something as simple as Torrington bearings on top and bottom of the 2.5" springs gave better course times and a more consistent feel for the front of the car. From what we can tell it let the spring turn under load. We marked the spring before and after and would see turning displacement with the Torrington bearings in place and none when the bearings were removed.

[RTz]

2.5" race springs 185F 215R - 12" tall.

 

What is the purpose of the long spring?

 

 

Additional rubber or urethane insulation creating a pesudo rubber isolated subframe.

 

 

Are you talking about putting a barrier between the crossmember mount pad and the frame rail?

 

 

new and custom door, window, and hatch sealing,

 

Quality seals are something the community is sorely in need of. Is it worthwhile for a few of us to pool some money together and make a small run of improved seals?

[260DET]

If I was going to build one, this would be my initial plan:

 

1975 280Z Chassis - A little stiffer and better corrosion protection then the earlier cars.

Single turbo VG30 engine - Tuned to about 300hp.

Z32 5 speed.

R200 with an OS Giken LSD.

235/45-17 tires on 8" wide rims all around.

Custom valved Bilstien shocks.

2.5" race springs 185F 215R - 12" tall.

Camber plates - rubber insulated.

Hypercoil hydraulic spring perches top and bottom.

Mostly rubber bushings.

Additional rubber or urethane insulation creating a pesudo rubber isolated subframe.

Complete Mazda MX-5 brake system including ABS, computers, MC, booster, wheel speed sensors, etc.

 

Then lots of detail work on interior sound deadening, big rattle elimination effort, new and custom door, window, and hatch sealing, 350Z seats...

 

How about the even stiffer S130 chassis with a single turbo VG30, Z32 gearbox, R200 torsen LSD and so on? Check my avatar car

[tube80z]

Yes. And in testing on the front of Toby's FP E36 BMW, something as simple as Torrington bearings on top and bottom of the 2.5" springs gave better course times and a more consistent feel for the front of the car. From what we can tell it let the spring turn under load. We marked the spring before and after and would see turning displacement with the Torrington bearings in place and none when the bearings were removed.

 

I asked Claude Rouelle in his seminar what he thought of the hyperco perches and he said there were no better than the torrington bearings and caused problems with frequency response in the suspension. He shared a few cool videos from Ohlins engineers that showed how much the spring would rotate and bend out of plan under load. I think Hyperco may have something similar on their site.

 

In the ICP seminar (Richard was a presenter) he talked about the perches and how back in the days of IMSA GTP that they would often see shock shaft failures from the bending loads being placed on them. These perches remove most of that and allow everything to more with less friction. When I asked about struts he said that they tested in a dyno and it looked okay but on the track the side loads caused so much friction there was no real benefit to be gained. For a street car I wouldn't use these as they require frequent rebuilding unless the design has recently been changed.

 

For Toby's BMW has you tried hanging the ARBs from heims as has been discussed before. It makes a similar contribution.

 

Cary

[BRAAP]

If you take that same $60K and spend it on a S30 you can get pretty damn close to that M3's level of performance and comfort. One of the keys on reducing the NVH on a S30 is to emulate the concept of a rubber isolated subframe that all modern performance cars have. Isolate the front cross member, TC rod mounts, rear transverse link brakes, front diff cross member, and the strut tops and you've gone a long way to reducing NVH in the car.

For what its worth, all BMW E30 and E36 cars have much of the front suspension solid mounted to the unibody. Only rubber isolation is the Lollipops and upper spring perch/hats. X-member is solid to the frame rails, lower controls arms are solid to the X-member, rack is solid to the X-member, etc. Though in defense of this, BMW did use a lot of sound insulation on both sides of the firewall as well as IN the trans tunnel and inside the car over the trans tunnel, floors, etc.

 

 

If I was going to build one, this would be my initial plan:

 

1975 280Z Chassis - A little stiffer and better corrosion protection then the earlier cars.

Single turbo VG30 engine - Tuned to about 300hp.

Z32 5 speed.

R200 with an OS Giken LSD.

235/45-17 tires on 8" wide rims all around.

Custom valved Bilstien shocks.

2.5" race springs 185F 215R - 12" tall.

Camber plates - rubber insulated.

Hypercoil hydraulic spring perches top and bottom.

Mostly rubber bushings.

Additional rubber or urethane insulation creating a pesudo rubber isolated subframe.

Complete Mazda MX-5 brake system including ABS, computers, MC, booster, wheel speed sensors, etc.

 

Then lots of detail work on interior sound deadening, big rattle elimination effort, new and custom door, window, and hatch sealing, 350Z seats...

 

Excellent Z package. The Nissan V6 being a very small and lightweight package capable of 300-350 daily driver HP, use of mostly rubber bushings with a few strategic durometer changes in a few locations.

Couple things I would change with only 300 HP as the level to shoot for that would help compliment the weight savings of the little SOHC V6. Z32 trans is physically large and heave, overkill if only 300 HP is the goal. That trans is right at the same weight as the T56 and personally, if I could use either one, I would take the T56 over the Z32 trans every time for it’s available gearing and its synchros are not as fragile. Only reason I would use the Z32 trans is if it was a direct bolt up and already had one. I more complementary choice would be the World Class T5. In stock trim is plenty adequate for 100,000 plus miles at 300 HP and is saem weight as the DAtusn L-series 5 speed, (50 lbs lighter than the Z32/T56 trans) and physically smaller leaving more room in the tunnel for exhaust, (ran one in my V-8 Z for over a year of abusive street driving, running 12.3 @ 113 MPH in a 2900lb ’75 280-Z , never gave me any trouble and was one of the nicest shifting trans I have driven. I'm sure other experience is probably different).

 

R-200, only if I were planning run it as hard it can be run drag strip or lots of HPDE with "energetic" shifts and stickier than typical street tires. Other wise for a 300 HP boosted V6 that doesn’t produce the instant torque/shock loads of a comparable HP larger displacement V8 under similar driving conditions, I would choose the R-180 and save those few pounds out back.

 

Now if planning to 400+ HP, then the Z32/T56 trans and R200 would be definites.

My $.02

[260DET]

Brand new Z32 gearboxes are available, they have improved syncros, with the right oil in the box they shift as fast as you can shove the lever. Much better shifter than the T boxes which have a clunky rep in my part of the world.

[BRAAP]

Brand new Z32 gearboxes are available, they have improved syncros, with the right oil in the box they shift as fast as you can shove the lever. Much better shifter than the T boxes which have a clunky rep in my part of the world.

 

... And still 50 lbs/22.6 Kilograms heavier than a T.

[johnc]

I would prefer to go with the Z32 trans because its quieter then the earlier Z transmissions. The extra mass also helps dampen driveline vibration and I would also most likely run the Z32 driveshaft (the one with the CV in it) to also reduce driveline vibration.

 

The longer springs tend to improve initial bump compliance. I know its counter intuitive but they react a bit faster then shorter springs with the same rate. I can't explain it but I've seen it on a spring tester.

 

In general I'm not trying to make the lightest S30 when building for reduced NVH and comfort.

 

Toby's front roll bar is mounted in bearings (pillow ball mounts), runs a blade adjustment, and is currently mounted to the front LCAs via rod ends. We have the complete suspension on the E36 modeled in Mitchell and optimized the roll bar mounting so it does only its job with the least interference possible. We also found that BMW really knows their stuff and have tried to mimic a lot of factory geometry on a car that's 4" lower.

[Duey782]

http://www.b-quiet.com/brownbread.html

 

I have used this in audio applications with great success.

 

-Cheers

[Snailed]

 

4) Braking. Again, relatively easily as their are plenty of brake upgrades out there, though expensive especially if wiling to modify or replace the Datsun suspension with more modern designs that have less compromise in them, (and NO, the Nissan Multilink crap does not fall under better! It only works good when made so stiff its doesn't have to travel, which semi trailing arm will also work just as well and weighs less.)

 

 

Which multilink crap are you refering to? Rear suspension of the 240sx/skyline/q45 or newer stuff?

[BRAAP]

Which multilink crap are you refering to? Rear suspension of the 240sx/skyline/q45 or newer stuff?

 

My apologies for not clarifying. Referring to the Multilink that was designed on the CRAY super computer in the '80's installed on the 240-SX, Z32, Q45, J30. I am not familiar with newer design used on the 350-Z/G35, totally different design an have not owned one.

[bjhines]

We cannot forget safety as well. The S30 has none of the safety features of modern cars.