ProjectB10 - 1993 Eunos Presso HI-XS

[projectB10]

[RX8SE3P]

Love the dedication to your beast! Do you have the super pro part numbers for all the bushings you used? How do you rate the ride quality improvement after doing all of those bushings?

[projectB10]

Love the dedication to your beast! Do you have the super pro part numbers for all the bushings you used? How do you rate the ride quality improvement after doing all of those bushings?

Thank you RX8. I confess I have a Presso "problem". I will persist until I have cleaned out (fitted) all the bits and pieces I have gathered up over the years. I am having a transaxle built up with a MS LSD, a reinforcement plate, all new bearings and synchros and longer 5th gear. Will bolt that up with the built up motor and drop it in the red car and call it quits I think. Just track day it from there.

I am cheating a bit at the minute though as have been am selling off stuff that i know I will never actually use, on TradeMe.

As for the bushings, it started with this guy who was registered as Zydawn on forums.teameunos.com and other sites. He set up a SuperPro bulkbuy about 10 years ago. Take a look here.

http://forums.teameunos.com/viewtopic.php?p=40262#40262

In my opinion the ride quality is as good or better than the OEM. Nice and tight and very predictable in terms of placing the car in the right place in a corner or a lane.

But that is all based on the before and after assessment in driving the car. I just remind myself that I am swapping out almost 20 year old OEM bushings for aftermarket stuff (SuperPro) which is rated in either the same or sometimes harder durometer hardness rating.

It is hard these days to get the harder durometer bushings which were offered for some of the fitments. The small range of stuff (almost all SuperPro) that is still available is marketed as an OEM replacement which means ....soft!.

The Whiteline bushings are very hard (impossible) to come by now.

[RX8SE3P]

Haha I do have that thread by zydawn open in another window just realised you actually posted in it too

I saw that he used SPF 2417K but you also had SPF 2415K. Is the 2415 just a standard option and the 2417 that double offset thing? Not sure I need double offset.

Btw very jealous of your garage space. I'm looking to move house soon and get something with decent room for my cars! Then I can develop a similar collection problem

[projectB10]

...............I saw that he used SPF 2417K but you also had SPF 2415K. Is the 2415 just a standard option and the 2417 that double offset thing? Not sure I need double offset. ......:

Yes missed that point in my post. Its an absolute no brainer to my mind. The SPF2417K is the way to go if a DIY "control arm" rebushing is on your mind. I changed my direction on which bushing part to use very late in the piece.

The SPF2417K bushing set is still very available and can be purchased easily on line. That little bit of added caster improves the turn in and front end stability in a very noticeable way.

[RX8SE3P]

Cool, so there's nothing tricky or any negatives about using the 2417 over the 2415?

Btw, would love to see some vids of your car running!

[projectB10]

Installed a Whiteline Sway Bar adjustable link kit. Probably not good value for money on reflection!

The kit is pricey!!!

Very straight forward to install. No corrosion on any of the inplace OEM fasteners. I have been in here recently of course.

The kit compliments the Whiteline Sway Bar I fitted just a little while ago. I didnt use the Whiteline 17mm and 14mm fasteners from the kit. I prefered the OEM 17mm Nylock style nuts from the OEM links.

The adjustability factor could be useful down the road a bit once this thing is finished.

In the mean time i can be very sure there is no unintended side to side preload of the bar as a result of mistmatch of the aftermarket sway bar and OEM links. I really knew that any way, as there was no forcing at all required when I installed the Whiteline bar with the OEM end links.

[WhiteFinish]

Looks are good, what does it do?

[projectB10]

The adjustable end links allow what is known as " corner" balancing. It's difficult to set up corner balance correctly without adjustable sway bar end links.

Very roughly, to corner balance a car, any "pre-load" effect from the sway bars has to be released or removed to get a correct "corner weight" reading on a set of scales. However usually when the sway bars are reattached you will find that the recorded weights for each corner will have changed.

Adjustable sway bar end links can then be used to adjust the bar. so as to achieve or restore the corner weight that was achieved with the bars disconnected.

The goal is to achieve corner weights that are the same with and without the sway bars connected. That is a situation where the sway bar is applying a zero value pre-load. Obviously they also provide the means to set up a track car by shifting weight around the corners of your car through applying an intended pre-load (to move weight from the right side to the left side, or from the right front corner to the rear left corner and so on).

A bit of overkill with my current strut/spring combo. My intention (given a little more time) is to set this particular car up on a full set of coilover/adjustable height struts.

[projectB10]

I decided to experiment. I have been running the 17 inch +40 offset rims with the low profile tyres with koni's and HR springs for a long time now. I use a 15mm spacer to bring the total offset down to 25mm.

This set up is effectively a +2 diameter over the OEM 15 inch rim. A +2 diameter increase is a big ask on a simple "short stroke" (front) strut suspension such as used in the Eunos.

The overall ride is just no fun as the road surface has to be perfect. If not then the ride quality is very harsh and takes away from the fun of running quickly on the twisties and average road surfaces.

So my experiment was to go back to OEM rims running some well used "no name" 195/60r15 tyres I had already fitted up to a set of rims. I had to use the 15mm spacers otherwise I would have had a rim fouling issue with the Mazda Lantis brake calipers/rotors fitted to this car.

What a difference. I should have done this years ago. I haven't lost anything in terms of "acceptable" grip and handling on "public roads". The ride and handling combination is light years better.

The look is not as good but the drive quality is much better.

I have another set of OEM rims fitted with near new Dunlop Direzza Z101 in 205/55r15. I will try those next. I think a 20mm wheel spacer with the slightly wider 205mm section tyre would be the best outcome.

[projectB10]

I intend to fit short primary style headers (OBX) when the new engine KL and strengthened MTX transaxle is swapped in to the red car in January.

The Short primary style have design faults which limit performance. The worst fault is the very poor collector design where the secondaries merge with the flexible bellows.

The long primary style offers superior performance but the design also reflects some manufacturing flaws (lousy fit) and design compromises. The step in pipe size primary to secondary is excellent as is the size and quality of the merge collector arrangements both at the primary 3 to 1 and secondary 2 to 1 points.

On my OBX set, the OD of the 2 to 1 merge collector is a miserable 55mm OD. The pictures show the very obvious step up in diameter where the collector is welded up to the flexible bellows where the OD is 63mm. Another consideration is that at a guess the OBX collector merge angle is something like 20+ degress while the new collector 2 to 1 merge would be about 15+ degrees (an eyeball guess as I haven't measured that dimension yet.)

So I purchased a SS 2 to 1 merge collector (2 x 44mm ID inlet slip fit style with a 63mm OD outlet) and a 63mm ID x 200mm Bellows. The intention is to cut off the OBX merge collector and bellows etc and fitup the new merge collector and bellows.

A lot of work. The new SS 2 to 1 collector was a bit pricey!!! I was surprised. Probably explains why the OBX merge is crap.

It will be worth it, as it will get rid of small diameter (55mm OD) restriction at the end of the OBX secondary pipes. By way of comparison the Mazda OEM exhaust pipe dimension at that point is 58mm OD.

I will take the bits in next week and get it all welded up.

[projectB10]

Ok job done.

The secondaries were tack welded down on to a rough jig so that the parts would NOT move (in relationship to each other end to end) and the OBX 2 to 1 merge collector was measured up and the necessary length cut out.

The OBX Bellows was retained. The new SS 2 to 1 collector was slipped on and welded in place.

The OBX merge is a poorly manufactured PoS! As a result of the way that the merge join is constructed by OBX the internal diametre at the pipe merge join is very much reduced and is a real choke point.

Take a look at the pictures;

In the first picture you can see the "huge" step up in diametre in the OBX piece (55mm OD to 63mm OD) right at the lip edge.







Compared to this



And the finished piece. The nice chrome finish is history. Not pretty anymore but function is king!





Again I am guessing not value for money...probably. Far too many additional $$$ required to make the fix. I certainly wont have any "before and after" power adder comparisons to waive around. At least I know that I wont be bolting up a second rate bodged chinese merge collector.

[WhiteFinish]

Very nice !

[projectB10]

Rant time.

I know these Chinese manufactured Headers are inexpensive. I know you get value when you pay for it.

But the more I look at the merge collector "off cut" the more frustrated I get.

What is the point of developing and selling an add on power adder like this with a deliberately inbuilt Power Subtractor "feature".

What a mess! On this particular set, the 2 pipes making up the secondary section (2 each of 40mm ID) are merged (very crudely) into one 40mm +/- 2mm ID outlet pipe. All that forum based discussion about back pressure effects and whether 52mm or 63mm or even bigger diametre exhaust pipe section is the best street power choice is rendered into a bad joke.

If this is a typical build example for the short primary "style" headers then it is NO wonder they produce such mediocre dyno results compared to the Long primary style.

I have a set of these short primary style on the other car. Looks like I have to do this twice.

[projectB10]

Little update. Picked up the finished gearbox. It will be fitted to the red car. It has been a long wait!!!

It has been fitted with a Kaaz plate LSD, a Ftjandra steel reinforcement plate, new bearings and synchros where required. My preference going in, was to use the Mazdaspeed LSD. The guy doing the build thought the Kaaz offered a superior solution. The 12 clutch plates, contained within the LSD, can be set up in three different ways to offer; #1 100% lockup for racing applications, #2 with 60% lockup as a performance track/road and #3 offers a 40% lockup which is really for road use only. I went with 100%. The red car is intended as a track day fun car.

The gearbox will have to be dismantled and the LSD removed if I want to repack the sequence of clutch and friction surfaces to reconfigure the level of lock up.

The usual KL internals have been ditched in favour of a complete gear set taken from a FS powered Mazda 626. It uses the KL MX-6 4.105 crown wheel and pinion. I have a 0.717 5th gear set to add to all of that as part of the install.

This box is built up from 3 G series Transaxles;

An MX-6 (KL powered) box which had an open diff oppps and as a consequence smashed up the bell housing. A MX-3 box that donated the replacement bell housing section and an FS powered 626 that donated the gearset internals (I wanted the higher/longer 3rd and 4th gears).

So I am left with a big pile of cases, gears and bits and pieces.