rob

checked the ballast resistor? (assuming it has one)

the manifold has been buzzed/milled out, so no ug welds on the inside - it looks hoary-as-fuck from the outside, but the part that counts is nice-n-smooth it does change from round (the itbs) to oblong (the ports), but i dont see any way around that. the bypass valve would be controlled by the megasquirt - means i can adjust the airflow with a computer, easier than buggering around with the linkages imo im pretty much 99% convinced that an idle-bypass is the way i want to go - i'd like to retain the efi niceness of ease of starting/warm-up etc. if someone with some spare 20v itb's could measure the diameter of the bypass holes in their runners/manifold for me i'd be forever grateful cheers, rob

+1 not after mexico-style flares but my ae70 ht will need its guards rolled/lipped and i'd like them done properly and as close to factory-looking as possible

check your radiator hoses. i had a teensy tiny itsy bitsy split in one of mine (so small it was almost unnoticeable), but it was enough to make the car run about 1/4 hotter than it should. replaced hose for $8 and she runs like a minter now. also whats the condition of the coolant and the oil? could be a blown HG/cracked head.. they can be pretty sneaky sometimes.. I've had blown head gaskets that didn't foul the water or the oil, but if you took the cap off the radiator you'd notice the odd bubble coming up.. this made the car run hot too.

roman: yeah - im still mulling over the approach i'm going to take. so far i've changed my mind from slightly-opened butterflys, to bypass pipes in the runners controlled by a valve, back to the opened butterfly's after reading that a bunch of people here are running them this way and now i'm leaning towards the bypass in the runners again - go figure my biggest concern with the lines tee'd in to each runner was that it would negatively affect the airflow through the runner, but after reading up and finding out thats how factory does it, i figure it can't be all that bad.. i have read that map sensor with itb's can be a bitch - but due to how my bodgey manifold is, theres very little space for an airbox of any kind - so running an afm would be a bit of a challenge too. kpr: if you could measure the diameter of those bypass hole's in the factory manifold that would be awesome! the engine is just a stock standard smallport - only reason i'm running the itb's is because i've pinched the smallport intake for another project i've also got a set of gze injectors laying around that i thought i might chuck on there... its just in a kp60 with a k50 - so its not gonna be a driftweapon or anything. it can get pretty chilly during the winter down here (chch) so i'm liking the idea of having a factory(ish) idle setup. going to be running the ms2 with the tps and a map sensor - and an additional map sensor for real-time barometric correction

my friend who is doing the megasquirt is concerned that slightly-opening the butterfly for idle may negatively affect the throttle response during engine deceleration, especially when under no load i.e. changing gears. considering that all of factory systems (that we've seen at least) set their butterfly's to close completely and use a valve that by-passes the butterfly, do any of you think that being able to close the butterfly's completely would improve the throttle response between gear shifts? maybe we're being too pedantic here..? cheers, rob

hi guys, thanks heaps for your replies my original plan was to set the stops to open the butterfly's a little to provide a "base" amount of airflow and then provide extra air (for cold starts etc) with a stepper motor operating on the linkage. so ive had another look at the TB's and you guys are right - there is a bypass in the TB itself! can't believe i missed it because its also shown on that page i found with the 20v itb info. thing is now i'm unsure why the factory setup has the additional bypass pipes built into the manifold.. something to do with having the engine being able to run in a *huge* range of conditions (like arctic circle/sahara styles) maybe? i had assumed that i'd need control over the airflow (either via stepper motor operating on the linkage or an electrically-operated valve) in order to have trouble-free cold starts etc, but if i can get away with richening up the mixture and just having the butterfly's statically set, then that sounds sweet to me. since you guys reckon it'll work fine with the existing TB bypasses and opening the butterfly's a bit i think i'll just roll with the TB's as-is. sounds like they should be work well enough to get it running at least - if it proves to be too much of a pain in the butt getting it to idle nicely i'll look at getting the extra bypasses drilled. p.s. i'll be using a megasquirt to do the spark and fuel on this thing

ok.. so a while ago i picked up some ITB's from a silvertop 20v that have been butchered onto a smallport manifold which let me use the smallport fuel rail. only problem is that they're missing the idle bypass pipes that the factory 20v uses to keep the engine going when the butterflys are closed. from what i can tell, other "off the shelf" 20v-itb-to-16v manifolds suffer from the same problem - at least the one that t3 sells appears to... i briefly toyed with the idea of a stepper motor setup to operate the butterflies, but decided that it would probably be difficult to tune and was unnecessarily complicated when compared to an idle bypass setup, which would consist of some pipes and a single valve. i found some pictures of the factory setup: (came from http://www.my-acoustic.com/Car/vacuum/4_throttles'_vacuum/4_throttles'_vacuum.htm) but because of my fuel rail, theres not really any space to have the bypass holes coming in from above like the factory manifold, however there is enough space on the under-side of the manifold to sneak them in. the bypass holes would be going roughly where the black X is, indicated by the red arrows. this is the same layout as the factory setup, but coming in from the bottom, not the top. so, i have one question and need one favor the question is: can anyone see any problems running the idle-bypass holes in from below? and the favor is: does anyone have a factory set of silvertop ITB's laying around that they could measure the size of the bypass hole on? cheers, rob

I got the complete altezza IRS nugget off trademe for $575 inc shipping from auck->chch, it came from some car importer who was removing it to replace with a factory lsd as this one was "too tight". Definitely worth getting the whole thing cos chances are your 30-year-old f-series diff has pretty tired pinion bearings etc and these swap over fine from the altezza diff into the live-axle housing. Of course you could always buy all new bearings... Cost me $280 for the guy to fit the lsd, pinion, bearings etc and a new pinion seal. $80 too much it would seem. Damnit. Since getting this done, I've been told of another guy who does gearboxes & diffs in chch, will be visiting him next time I need something like this sorted.

what would tuning for 91 involve exactly, retard the timing a bit? go so far as to re-jet carb? not sure that running 95 in my car equates to blowing money on aviation fuel, all i said is i've observed my cars run better with 95 sounds like if you want to be sure you should go back to guy's who did the work on your head and ask if it's ok for you to run unleaded fuel with your new valves/seats/whatver. but like shizzl said, it'd be pretty unlikely for someone to rebuild a head using bits that couldn't handle modern fuel, so chances are you won't need the additive.

i wouldn't run 91 in my lawnmowever seriously though, all my bog-standard, rattly old toyota motors run smoother when supping 95, dunno about "extra power", but quieter/smoother running is worth the additional few cents per litre imo.

I have a '79 rt132 and I'm pretty sure it's got a steering box.. When I did the conversion from steering box to rack & pinion on my ae70 corolla I needed: [*:1asqjiyt] Rack and pinion steering column [*:1asqjiyt] Rack and pinion steering column shroud-thingy (end of the steering column slots into this and then it bolts to the firewall) [*:1asqjiyt] Steering rack (obviously) [*:1asqjiyt] Steering rack engine cross-member [*:1asqjiyt] I also used the lower arms, but I think the steering-box lower arms would have been fine. Got all these pieces from a steering-rack ae70, everything fit up with no mods. I'm guessing the same would probably apply to your car - find a rt132/tt132 with rack steering and grab all those bits I listed above, swap them into your car and you should be right This is assuming there are t132's with rack & pinion (does someone know?), if there aint you'll have to find a rack setup from a different car (maybe a newer corona?) and chances are you'll need to do at least a few modifications to fit it.

Hey man.. diff is still in pieces at the moment, but I measured it with a tape before I pulled it all apart and it was 1420mm from hub to hub, give or take.

Hrmm.. The guy I bought it off actually said it was from a MA63, but I've never heard of one of these being live axle so i figured he just got the numbers mixed up (63 -> 46?). Might be a MA63 diff then, not a 46 Its 4-stud disc brake and about 1420mm wide. Looks identical to MA46 pics I've seen on the net. Yeah, I think the old guy was telling me they used the c/w + pinion gears from the open diff, but swapped over the pinion + carrier bearings from the IRS diff, but I recognise the open-diff's gears from the marks I made on them to check the ratio and they're both sitting in my bucket of leftover bits, not in the diff.. Cheers dude, have come across heaps of the stuff you've written on the net and it's all been ace!

Yeah thats what the old guy said - in good nick too apparently

Sorry bro, I believe my diff is out of an MA46 Celica/Supra, not a Crown. BUT this shouldn't matter, as all Toyota 7.5" F-series live-axles share the same diffhead (afaik anyway), so if your Crown has an F series diff then this swap should work for you. I just started asking questions on this thread after I came across it looking for info on F-series LSD setups and noticed there were some knowledgeable people posting here

Ok, so I called the diff shop this arvo and it turns out they'd just finished with my diff - all fit in sweet they said. Awesome! Go in after work to pick it up and talk to this older guy who gave me the impression that he was the one who actually did the work, turns out everything inside the Altezza IRS housing, including the crownwheel and the pinion + its bearing, fits into the live-axle diff housing, no spacers or any funny business required. Also for this LSD at least, there was no need to trim the axles. Internet: 1, Younger cunt at the diff shop: 0 Stoked!

Nah, I didn't get the impression that the guy had done this specific swap before - and our discussion about bearings etc. all happened when I dropped the bits off at his workshop, so before he'd been able to measure anything up. He had to ask me what spline the axles were so I'm not totally convinced he knows the full ins and outs of these diffs. The guy rebuilds diffs for a living though, and appears to be the only outfit in Christchurch so I figure he's capable-enough. More pro than I am anyway.. Ah so it's the bearing width thats different! That would probably help explain the different part numbers. When I read elsewhere that the LSD centre was larger, I just assumed it was the circumference of the centre that was bigger - also that Celica-Supra MA46 Diff Swap howto lists the non-LSD MA46 bearing as having a slightly smaller ID than the LSD MA46 bearing. Pretty sure they're the same ratios - counted up 41 teeth on the crownwheel and 10 on the pinion in the open-diff, and same on the altezza crownwheel. Damn.. didn't think to ask what type of altezza the diff came from - Stupid. Have fired off an email to the guy I bought it from to find out... just waiting on his reply. However when I had the open diff and the altezza diff side-by-side, the crown wheels looked freakin' identical size-wise, the only difference I could spot was a slight variation in the shape of the side of the altezza crownwheel (i.e. not the teeth) - maybe this is the cause of the different offset that some people mention.. Kicking myself for not pulling it all apart and doing some more measurements before I took it in to the shop - Had just assumed it'd be smooth-sailing.. Foolish It's really just wait-and-see at the moment I guess - the diff guy reckoned he'd have it ready by the end of the week - and as of yet I haven't received any phone calls telling me the bearings are different so I'll cross my fingers and hope for the best! Will post updates when I find out more

So.. took the Altezza LSD, the live axle diffhead housing and the axles into the diff shop yesterday. I had assumed you could use the Altezza crownwheel and pinion, but the guy said they had a different offset and that he'd have to swap the live-axle diffhead's crown wheel onto the LSD centre and use it with the live-axle pinion in the housing, ok thats not really a big deal as they were the same ratio anyway.. He then proceeded to tell me that he was pretty sure the Altezza's carrier bearings had a larger outer-diameter and would most likely not fit into the live-axle diffhead housing. I told him that I had it on pretty good authority (teh intarwebs said!) that the only difference is the bearing's inner-diameter, and this is due to the LSD-centre being larger that the open-diff's. So we kinda agree to disagree, and he says he'll do the swap and that he'll give me a ring if anything pops up (i.e. bearings are different, as he says). I head home and decide to try and edjamacate myself some more on this bearing bizniz, I manage to find a website selling Toyota Part #90368-50006 as the side bearings for an LSD SXE10 Altezza. This part number matches the part number given for a "Tacoma" (I'm guessing this is American for Hilux) F-series front diff, on the "Celica-Supra (MA45/46/47) diff swap" post that is on various sites around the net (I figure you guys have already seen it). This post suggests that this 90368-50006 bearing *may* be necessary to run an LSD in the F-series housing, but the author isn't 100% sure. The post also has the carrier bearing part# for the live-axle w/ LSD as 90368-50024 - different part# to the Altezza/Tacoma, but the guy has got some measurements taken from the various bearings which lists the Tacoma's bearing as having identical dimensions to the MA46. So assuming bearings #90368-50006 are what my Altezza diff is using, I'm thinking that they should fit into the live-axle housing, despite being different part numbers. Is anyone aware of there being any variation in the outer-diameter of the carrier bearings between live-axle and IRS F-series diffs? or maybe even between live-axle diffs from different cars etc? Basically I'm kinda suspecting that this diff guy is just telling me that the Altezza bearings aren't going to work so he can pad-out his fee.. Then again I could be mistaken, or equally so could he. If he comes back to me and says that the Altezza bearings won't work and I need to fork out for some new bearings, it'd be nice to be well-enough informed to tell him that he's spinning stories - or not He also predicted (carrier bearing issues aside) that the old pinion bearing would be the first bit to go once the LSD was being used in the live-axle, as the LSD centre will put more force on it and eventually bust it. This seemed to make sense, but I was wondering if any of you guys who've swapped an LSD centre into a non-LSD housing (with a used pinion bearing) have had this happen, and if so how long did it last before giving out? (obviously this would depend somewhat on the condition of the bearing to start with). The price he quoted for a diff rebuild to replace the pinion bearing was more than I can afford at the moment

yeah man, all good. i'll take the word of someone who's done it over a random forum post i think i read somewhere and now can't seem to find thanks for your help!

thanks heaps for the info guys.. crazy, i could've sworn i read elsewhere that the clutch lsd's were usually sweet with the non-lsd axles and it was the factory lsd that needed them shortened slightly due to the torsen centre being all full of gears n stuff ah well getting that done is no biggy.. cheers!

ok.. i'm gonna dig up an old thread here. would someone who's swapped an aftermarket altezza lsd into an f-series live-axle be able to tell me what side bearings i need to use? i've got a complete altezza irs nugget which has had some sort of clutch-type lsd installed into it. i was hoping to be able to use the altezza bearings as they're probably at least 20 years younger that the ones that are currently in my live-axle diffhead... if it turns out that i have to use side-bearings specific to the live-axle head, does anyone know the part numbers? also i've read that you need to give your axles a bit of a trim if you're installing an altezza torsen lsd into a live-axle, but is this necessary when using the clutch-type diffs? tia

if you havent found it already, this page: http://www.billzilla.org/4agstock.htm has some good 4age info - especially if you need to work out what kind of 4age you've got. theres pics of the different port designs about halfway down.. big port is quite wide and flat compared to the smallport. also smallports have an oil return at the back of the head on the right side - if you've got one of these you'd probably want a smallport block so its got somewhere to plug into, plus those extra ribs cant hurt ive got a smallport sitting in a mates garage and could get you some pics of the block/head if you want