Turbo gearbox

87THS · 12-08-2006, 07:02 PM

Hi all. My name is shane and I'm new to this forum. I have a ford laser SR2 which I have turboed. Currently have 300hp at the wheels with this small turbo but I keep smashing my gearbox.

Does anyone know where I can get a hold of a mazda SP20/or laser SR2 turbo LSD gearbox. I believe america has but fail to find.

Would be appreciated if anyone can help.

Thanks.

:

dirty hands · 12-08-2006, 11:23 PM

ask here also http://www.mx6.com.
only other thought is to have a gearbox repairer fit the LSD and turn the boost down till you upgrade the box
what is the gear box ratio difference ?

87THS · 13-08-2006, 04:50 PM

Hi mate. Thanks for your interest. The car is only on 14 p.s.i. at the moment. I have thought about trying to fit a MX6 LSD into the box but just still unsure if the gearbox will hold. At the moment it's not the gears smashed it's the linkages I believe. I can still drive but in 1st 3rd and 5th with a big noise.

I can't select 2nd 4th or reverse. I can't tell you the ratio as I can't find where I have it. The other problem I had is can't select 5th down willowbank. With all weight (including spare) and a 2.3sec 60 foot time I ran 13.65 at 171km per hour but last 50 odd metres I was trying to put it in 5th but all it would do is rev out even though It was in gear.

Once off boost at normal driving 5th was perfect. Sorry about all this info but trying to fix this car. :voldar02:

dirty hands · 13-08-2006, 10:02 PM

i did a web search as sr2 gearbox
Ford Laser SR2/Mazda 323 SP20 owners- help please!!!! - Ford

it may mean the syncro mechanisim has had a failure in the selector part of the box
probably a clip that is held by the selector shift support part inside the gear box
there are 3 slides in the synco part held in with tension if one clip slips off ,the slides drop and you cant change gear it just jams the mechanisim

more annoying because the box has to come apart but new clips and circlips should fix that as long as the cogs are not broken or damaged

5th and reverse are linked in some way wish I had an exploded view to show you where the problem is
was the clutch slipping in 5th at the end of the run ? oil on the clutch !

VippiN · 15-08-2006, 12:07 PM

I'm not too technical with KQ onwards, but if possible, see if you can backtrack to the KF/KH TX3 FWD Turbo gearbox (G Series) they are quite strong from what they are, able to hold the power you're talking about.

Though buddy no box will die if you treat them properly.

tmg · 15-08-2006, 02:36 PM

How hard are you driving the thing? Sounds to me like you're redlining each gear and smackin it through the gears = pulping your syncros and cogs nicely.

14PSI is a lot of boost as well - IMO - so maybe turning it down is a good idea...

that's my 2 cents....I hope you get it all sorted out man, SR2's are nice cars :Reverend:

87THS · 15-08-2006, 06:25 PM

Thanks for all your input on the matter. I've managed to find billeted gear for my gearbox and LSD. With the 5th gear problem I have reason to believe it's the crank angle sensor. Would any of you know of a similar problem?

The gearbox has only broken for the second time really. First was 3rd gear breaking some teeth and now the gearbox letting go in 2nd. I do drive it hard at times but no redlining. My car redlines to 7500 but my shift is set at 5500.

The engine is strong. I was told the gearbox would not hold forever. But I was also told my CV would not hold but I still have the factory CV in.

Hope to meet you all out there one day on a cruise or at a show. thanks. :eclipsee_

VippiN · 16-08-2006, 07:03 PM

With gearboxes redlining isn't the issue here it's clutch dropping, or snapping it into gear on change.