Budget upgrades for the DIY

[Clevo120Y 815]

Lets share some cheap easy changes to get the most out of our crossies, I have a couple that I will post up later that I have been working on.

[XFChris 126]

Cheap is subjective.

 

But good spark goes a long way, particularly if running lpg.

 

Use a Bosch HEC716 (OEM coil AFAIK) or better. Made a difference on my car.

[Mixalis 266]

I remember when i had the stock very low comp crossy, one of the best things i did was bumping the base timing from 6 to 12 degrees, always filled with 98 as well. Ass dyno said big hp gains. $0 as i was filling up with 98 anyway. Obviously works for everyone but a great move for those just starting to muck around with a crossy 

 

Definitely seeing the benefits on a dyno now with the new setup recently.

[dougie77 789]

Take it out of a falcon and put it in a cortina............thats all i got lol  

[Clevo120Y 815]

Some quick and easy things to do is modify the aircleaner housing to let more air in as the stock snorkel and cold air piping is very restrictive, a stock webber flows 260cfm and the aircleaner housing reduces that down to 235cfm, use a holesaw and make some breather holes on the other side of the housing.

 

 

If you don't want to put holes in it or your not allowed to put holes in it then remove the rubber seal that is in the lid, this creates a small gap around the whole assembly and allows more air in.

 

 

If you want to make it even better and have no restriction at all put a rubber spacer on top of the aircleaner element, I have flow tested and you only need to raise the lid 6mm to have no restriction, I used some mdf rings to get the total height needed to register minimum restriction.

 

[Clevo120Y 815]

Now for some bigger gains, webber carby mods. Without changing the venturi size or throttle blades you can make a webber flow just as much as a stock 350 holley. just by cleaning up the imperfections in the venturi casting and gasket matching the whole thing you can gain just over 10cfm of flow through the carb,

 

 

Here is the big gain that I will share, I got the throttle shafts machined down a bit, I got it machined only as wide as the throttle blades and down level with the flat parts that the screws fix to, then the same amount off the other side, I did this to both shafts.

 

Original shaft

 

 

Machined shafts

 

 

On the flow bench this gave a 34cfm gain so with the other cleanup this carb now flows 308cfm, once I get my carb top back I will test it again and I'm confident it will go over the 350 holley flow rate of 320cfm.

This is the prototype of my webber carb top.

 

[ando76 4,354]

cheap upgrade - scan the speedway forums for 'used' speedway motors - some real bargains to be had there - ok you may have to freshen them up but I know of plenty of engines that have been off- loaded for peanuts really.  Remember shit like balancing and machining costs heaps so if you just have to throw rings, bearings and a gasket set at these bargain engines - you are miles ahead. 

 

Piss off the stock manifold and by the new aussiespeed 2 barrel manifold. even cylinder fill will build torque and HP and for $500 odd dollars is money well spent. 

 

Make sure the simple shit, like fuel, air and spark is all good.  getting the basics right will make good power. 

 

Freshen up old engines.  None of these engines are getting any younger so fresh rings and bearings - valve grind and head surface for more comp will all make a huge difference. 

[gerg 10,871]

That's awesome mate. Nothing like some strict class rules to get people thinking outside the box. Loving the Weber mods. Having owned an LPG crossy I can vouch for the suitability of these engines for this fuel... A match made in heaven. If I had my time over I'd do a few things differently, namely the ignition curve and the inlet manifold. If I still had it I'd be running MSD, spiral wound leads for sure and probably an EFI manifold instead of the poorly balanced Redline that I had. Over 4500 rpm it felt like it was about to grenade itself but this same engine in my dad's EFI XF felt sweet all the way to over 5000. If you're going LPG then go with one cam up from the equivalent petrol one you'd select, as LPG takes a higher volume in the manifold than petrol, effectively making the cam and manifold characteristics more tame.

[ando76 4,354]

Sean while you are at it - with the throttle plate screws convert them over to button head - you will pick up another couple of cfm. 

[slydog 7,873]

Take it out of a falcon and put it in a cortina............thats all i got lol  

 

This bloke is lost...

[slydog 7,873]

Well I got this 1 off Jase and the improvement was instant and very very noticeable.The key is the bigger the HP of the engine the bigger you go in ignition.

 

So for a stock to mild xflow grab a TFI or EST dizzy,a MSD Street fire CDI box and matching coil and watch your engine come to life.I know I recommended this set up to a few people and as yet had no one complain it didn't show a big improvement.So for your $250 outlay you get better economy,better faster easier starting and better performance.

 

A simple 2.5" exhaust Seans carby mods and the above ignition will see you having alot of fun with your xflow you will wonder why you didn't do it earlier  

[Hofiveo 47]

2 and a half straight thru and decent extractors was a noticable improvement on mine. Got let them breath.

[gerg 10,871]

Standard Ford cats are excellent but have restrictive inlets/outlets. A cheap mod is to cut these off and weld in 3" nipples to maximise flow through the "brick". A 3" pipe is actually fatter than the cat is top to bottom so you need to flatten the pipe out a bit which also serves to "fan out" the flow more evenly into the core. I like to shove a wet rag down into the cavity when cutting/welding so sparks and crap don't fall in and damage the core.

[Hofiveo 47]

Could knock the guts out the cat. Not legal but know a few guys that have done it.

[Mixalis 266]

Good info here as usual!

[adrianphu123 73]

How even is the flow in the EFI manifold? I moved from carby to EFI manifolds on LPG only and it felt a lot better.

 

I got a few tips:

 

Remove the power steering

Merge collector makes a big difference over standard formed collectors, seems to have quietened it down at idle.

T5 gearbox and 3.23/3.27 differential puts you in a better rev range compared to the standard 2.92

[ando76 4,354]

Not so even for the EFI manifold - the little plenum on top of the tappet cover tends to favour the middle two cylinders - but below 4500 they seem to be fine.

[Hofiveo 47]

I agree on the t5 or even a single rail. Manual box makes a big difference. Might not be to budget friendly but you can find them for the right price.

Diff ratio change will make it get up and go quicker aswell. Anything has got to be better than 2.77s and e series falcs for wrecking are everywhere. Should be able to find a diff for a budget friendly price.

[XFChris 126]

Clevo120Y:

 

Putting holes in the air cleaner housing would make it a hot air intake right? AFAIK hot air is good for economy, and cold air good for power. Though as it pulls from the intake manifold side, maybe the air there isn't that hot.

 

Or is any extra air going in, regardless of its temp, a good thing for power?

 

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On a different note, I've heard a 2 1/4 catback system is ideal for a stock, or very mild crossflow. Though it needs to high flow. I've even heard of people getting gains on a 2" catback on a stock xflow. Of course you want to pair that with a good cat (if legally required) and extractors. The stock exhaust manifold doesn't look like it flows too well.

[Clevo120Y 815]

Pulling air from the intake side is the idea as it will be cooler, plus if you have the cold air ducting still plumbed up it will keep the housing reasonably cool, the original housing is so restrictive even at a test pressure of 28in that a running engine that pulls a lot more than that is choked badly, so the extra air outways the temp of the air in this case by a long way.

 

This aircleaner mod has been track tested and improved lap times from 20.2sec  to  19.4sec with a 4kmh top speed increase which is a fair improvement.

[wagoon 2,429]

With the aircleaner mod, will the car need to be retuned at all? whether it be just turning the mixture screws or timing or something else, on a standard or slightly modified engine ie extractors and exhaust

[Clevo120Y 815]

The AFR's stayed exactly the same when we tried it, but a basic tune and some timing adjustments could be changed to hunt for the sweet spot.

[Hofiveo 47]

Not really an upgrade but check the carby is opening fully. Was tinkering with my xf today and the cable is that stretched it was barely opening the secondries. Adjusted it as much as I could and still won't give full throttel. Time for a new one.

[Mr Polson 10,214]

Not really an upgrade but check the carby is opening fully. Was tinkering with my xf today and the cable is that stretched it was barely opening the secondries. Adjusted it as much as I could and still won't give full throttel. Time for a new one.

 

Got caught out by this when i first got my ute, it never seemed to as hard as I thought it should, discovered the throttle adjustment meant full throttle only opened the primary.

[ando76 4,354]

This very issue has caught me out on the dyno more than once now, usually when I am slack and don't go through my 'pre-dyno' inspection list.