Link at 10+ PSI ?

[NickD]

What about a 1.8 LSD diff ? Are they any good ?

At 10psi your going for some major horses, so everything is going to be under more strain. I am not aware you need a new prop shaft ot for that matter half shafts, I could be wrong, ask my wife!
However, the Torsen LSD is a good unit. With the sort of power you are going for I would even look to get the six speed box and higher ratio diff as you will be able to pull a higher ratio without problem.

I don't know about MK1's or MK2, but the 2.5 6 speed box is mated to the Tochigi Fuji Super Diff will give you 30% higher gearing than the standard 5 speed. If you have 250 bhp and the torque to match, that would be my choice.

[Fergus]

I was actually just reading about that 'Tochigi Fuji Super Diff', seems to be one of the best out there. What about mating up to the 1.6 engine ? Is an adapter plate required or is it "plug and play" ?

[Steve]

Hey Nick,
Fergus is swopping from a 1.6 to a 1.8 diff so he'll need the shorter prop shaft and 1.8 half-shafts no matter if its LSD or not. I looked into getting a 6 speed box myself but decided against it as the 1st and 2nd gears would be next to useless (as 1st is now) with the rear diff I bought. Yeah, as you said, a higher ratio might have been a better idea but would it not have dampened the acceleration to 60?

I reckon if Fergus gets his tuning right he could be looking at a reliable 250hp.
I'm at 11psi for the last 6 years or so (DLL'ed at 247 last year.. it was a v.v.cold night ) but 3rd gear is starting to whine now. Its due a gearbox oil change, I'll put some new Redline MTL in and see how it goes.
Have had the chance to drive a 6 speed mk2 recently, great gearbox.. might have to get one if this 3rd gear gives up..

Steve

[NickD]

My understanding is that the third gear is the weak point on the box, in fact all of them. Normally the synco goes, depending on how you change gear of course.

You want a good quality 75 - 90 GL4 oil.

The recommendation for the modern box is GL5, but the EP additives are rumoured to be too slippy for the syncro, which as \I have a 6 speed on my car I would agree with. It works much better with GL4

If you have 250 bhp and turbo torque to match, unless you are drag racing I would go for the higher gearing diff. The 6 speed box puts extra ratio's up to 5th. 4th and 5th on a 5 speed are the same as 5th and 6th on a six speed.

Just be aware that MK1 have a cable drive for the speedo where as MK2's have and electrical output via a bit that Mazda will want £135 for if you need to by a new one. Time to invest in that Stack instrument panel

[Fergus]

2 5 0 BHP !!!
I've found a 1.8 LSD diff with prop and shafts but don't know what type of LSD it is yet, must go take a look at it today.
The guy also has a 1.8 gearbox.....and......I'm VERY VERY tempted.....a 1.8 engine with only 27k miles on it
Who knows whats going to happen now.

[leamyj]

Fergus!!! Are you looking for a quick way to get divorced?? Put away that credit card now!!!

John

[Steve]

2 5 0 BHP !!!
I've found a 1.8 LSD diff with prop and shafts but don't know what type of LSD it is yet, must go take a look at it today.
The guy also has a 1.8 gearbox.....and......I'm VERY VERY tempted.....a 1.8 engine with only 27k miles on it
Who knows whats going to happen now.

The 1.6 link won't run a 1.8 AFAIK.. (and you'll be needing a new turbo manifold.. the 1.6 one won't fit a 1.8 ).

Oh.. I thought the 1.6 & 1.8 5 speed gearboxes were the same tho no?

You could just put in a 1.8 clutch and flywheel instead.. alternatively an ACT clutch would sort you out.

[Steve]

My understanding is that the third gear is the weak point on the box, in fact all of them. Normally the synco goes, depending on how you change gear of course.

You want a good quality 75 - 90 GL4 oil.

Have this in there at the mo' :
http://www.redlineoil.com/products_gear ... tegoryID=7
Needs renewing tho ..

If you have 250 bhp and turbo torque to match, unless you are drag racing I would go for the higher gearing diff. The 6 speed box puts extra ratio's up to 5th. 4th and 5th on a 5 speed are the same as 5th and 6th on a six speed.

Think I'm missing the point still in relation to putting extra ratios in up to 5th (unless you are saying acceleration is not the main aim.. I'm rarely on motorways these days so cruising at a lower rpm wouldn't be high on my priority list) .. wouldn't this just result in lots more gear changing?

Time to invest in that Stack instrument panel

oohh.. link?

[NickD]

My understanding is that the third gear is the weak point on the box, in fact all of them. Normally the synco goes, depending on how you change gear of course.

You want a good quality 75 - 90 GL4 oil.

Have this in there at the mo' :
http://www.redlineoil.com/products_gear ... tegoryID=7
Needs renewing tho ..

This is the one you want
http://www.redlineoil.com/products_gear ... tegoryID=7

If you have 250 bhp and turbo torque to match, unless you are drag racing I would go for the higher gearing diff. The 6 speed box puts extra ratio's up to 5th. 4th and 5th on a 5 speed are the same as 5th and 6th on a six speed.

Think I'm missing the point still in relation to putting extra ratios in up to 5th (unless you are saying acceleration is not the main aim.. I'm rarely on motorways these days so cruising at a lower rpm wouldn't be high on my priority list) .. wouldn't this just result in lots more gear changing?

If you go the whole hog, with the (from memory) 3.6 diff as well, no, you will have, in my opinion, better ratios for acceleration.

If you stick with the standard gearing and that sort of power, you are still going to be changing a lot because you will be on the rev limiter in 2nd before you know it on full throttle. But yes, a 6 speed on the standard 5 speed diff and you will be changing gear a lot more. I wouldn't look for 6 cogs without the latter diff with that sort of power.
I have been in a 1.6 with about 270bhp and it was brutally quick. You do realise though, that tuning is addictive, and there is always that bit more that you want.

Time to invest in that Stack instrument panel

oohh.. link?

http://www.stackltd.com/streetdash1.html

[Steve]

If you go the whole hog, with the (from memory) 3.6 diff as well, no, you will have, in my opinion, better ratios for acceleration.

If you stick with the standard gearing and that sort of power, you are still going to be changing a lot because you will be on the rev limiter in 2nd before you know it on full throttle. But yes, a 6 speed on the standard 5 speed diff and you will be changing gear a lot more. I wouldn't look for 6 cogs without the latter diff with that sort of power.
I have been in a 1.6 with about 270bhp and it was brutally quick. You do realise though, that tuning is addictive, and there is always that bit more that you want.

Ah ok, so the 3.6 would be needed. I get it now. Cool!

Yes yes.. well aware of it LOL Frank Smyth pushed me into it "here ya go kid, the first bit is free.." heheh
Haven't changed anything really (powerwise) in a while.. but I've 440cc injectors in a box at home.. just waiting for the weather to warm up a bit..
BTW, heres my last power run (@11psi, add 23hp for drivetrain losses)

[NickD]

Here you go; this is the car I have been in. Steve Willington used to run Track-Tec tuning and is very knowledgeable.
If you need to know anything about turbo installs, and if you ask him nicely with a genuine question I expect her would give you advice. I am sure he can probably tell you just about as much as anyone in the country. He's on first name terms with people like Corky Bell and Keith Tanner.

http://www.slowmx5.com/index.htm

[Steve]

Ah yes, sound man is Steve, have had reason to deal with him in the past. Great car!

[Fergus]

I received the temp & knock sensors today.
Is it just a 'Boost control solenoid' that I need or do I need to get one of those complete EBC systems ?

http://www.flyinmiata.com/index.php?deptid=&parentid=&stocknumber=07-26500%20%201990-97

(edit) I'll also be getting a custom downpipe and exhaust system fabbed up which should set free some ponys.

[Steve]

I received the temp & knock sensors today.
Is it just a 'Boost control solenoid' that I need or do I need to get one of those complete EBC systems ?

http://www.flyinmiata.com/index.php?deptid=&parentid=&stocknumber=07-26500%20%201990-97

(edit) I'll also be getting a custom downpipe and exhaust system fabbed up which should set free some ponys.

yup, that looks like it, best to give them a ring tho to be sure.

Custom? Cool! Locally?

[Fergus]

Yeah, friend of mine is a fabber and he said he'd make one up no probs.
Trying to decide if it should be 3" or 2.5", probably start with 2.5" and make it bigger as it goes back to the exit