Heavy, auto, tall diff, stock/mild 308 - Quadrajet Light-medium car, manual , low diff tough 308- Holley DP Having said that, the top VK and VL Commodores at Bathurst in '87 were making 440hp from Quadrajets....
@stevegibbs721119 күн бұрын
There’s a Holley out there it’s a 650 cfm spread bore double pumper it’s got small primaries and large secondaries just like the qjet I’ve had a couple of them on different 308’s they go pretty good
@dazaspc5 ай бұрын
Used Quadrajet's for years on 253 and 308's and they were good. Parts and wear is catching up with them now however. A DP is a stupid choice unless you have a signifigant cam and are buying fuel at 60 cents a liter. 600 Edelbrook/Carter for the 308. Its a spread bore , has 3 stage metering like the Qad and doesnt have 30 years of wear in it. Parts are easy to get hold of. You will still get the big kick from the spread bore and part throttle is nice. A DP needs a lot of messing around to get close. Holley DP= Great at WOT and not much else. You will find it will work sweetly out of the box. When I replaced a Carter Thermo quad on my 302 with the Edelbrook it was almost perfect out of the box. Alternatively the Spread bore Holley's are ok as well but dont run as nicely and use a little more fuel But are far simpler to get close to a decent tune.
@TasTuned5 ай бұрын
You’re right, I got sucked into the idea of needing a holley dp if I wanted it to perform. Truth is I have a nice street car that loves the quaddy and barely spends any time above 4500 rpm
@brentonk461ismylostaccount5 ай бұрын
The answer is both. Both the Quadra Jet or a Holley. They can both be used depending on combination you choose what the Engine wants, tuning ability all comes into it. Use what the Engine wants. I have Even run As Big as 950 double pumper on mine no issues what so ever. Not for everyone though.
@TasTuned5 ай бұрын
Completely agree, for what I want to do and my setup I’m lucky this particular quaddy works really well. For something more serious or competition related the holley certainly are usually a better fit and much more easily tuneable for the common man
@dionosus5 ай бұрын
Remember, the quad is a vacuum secondary type carb. It groverns how much air the motor sees. So it suits low rpm pulls (typical street use) The double pumper opens all the butterflies at once and is hard to beat at high rpm race type flat to the floor use.
@TasTuned5 ай бұрын
Yeah very true, I forgot that aspect. I’d like to try the double pumper with a single plane manifold sometime to see how it goes at more high rpm but for occasional street use I’m lucky this particular quaddy works well for me.
@adamc46555 ай бұрын
She sounds sweet with the quadrajet
@richardstevens93085 ай бұрын
Did the same in my 72 HQ premier. Changed to a Holley 650 vac-sec and hated it. Blueprinted the q-jet and put it back on. Better response, smoother operating, same power but way more economical on petrol. Q-jet for the win
@TasTuned5 ай бұрын
Sometimes you feel pressured to “upgrade”for the sake of upgrading but yeah like you, for a street car I’m convinced. Quaddy all the way
@andrewhall8415 ай бұрын
Q-Jet any day, and they aew available in a number of cfm sizes from the 253 Holden fitments to Chevy big blocks. They are very tunable with adjustable power jets,different needles, and jet sizes for the secondary side and, of course, spring tension adjustment on the secondary air-valve butterflys
@TasTuned5 ай бұрын
To be honest I have no idea how to tune one, I just know that the one i have works amazingly on my setup and I’m lucky for that. Drivability and economy is awesome
@andrewhall8415 ай бұрын
@TasTuned if you're happy with it, that's fine. I just thought I would give you some tips on what's out there. The best way to tune them is lean on the primary side (13 to 14:1) and a little ritch on the secondary side(12 to 12.5:1). These days, a good wideband O2 sensor is the best/cheapest tuning tool. I use a Raytech automotive lamda2 .Cheers 👍
@sammuir58755 ай бұрын
Thanks for reminding me of own quad carb Kingwood back in the day👍
@dalewarriorofthesea39985 ай бұрын
The small primaries means instant strong signal off the get go then the secondaries kick in Remember it's only a small capacity and mild overall set-up
@franko694 ай бұрын
Quadrajet hands down the best carby for the 308 Holden engine.
@paulcost64465 ай бұрын
Quady on my HZ tonner daily for my business for sure.
@OVERKILL_EVERYTHING4 ай бұрын
So good to see you out putting some miles on it, definitely sounds healthier with quad on it. Looks like a great little camper you made too, should do a video on that too when you get a sec
@finlay2305 ай бұрын
such a cool car, sounds awsome !!! its a real driver !!!!!
@kuseetha.4 ай бұрын
Sounds great mate!
@Tk-ou9ec5 ай бұрын
I’ve got a mild 318 in my Chrysler, and I’m running an edelbrock 500cfm 4 barrel carb. To small? Dunno but it’s been tuned and runs great. Over the years I’ve had holleys as well but I’ve had issues in the past with Holley as in going out of tune and so on! This edelbrock has been on my car since 2019 and I’ve not felt the need to tamper with it as it just stays perfect! No shit. I will always run edelbrocks from now on and they are easy to tune and no messy fuel going everywhere if you should need to change jets as the top of the carb comes off,not a front fuel bowl. I’ve often wondered how mine would perform with a bigger carb but I was advised that the 500 was ample for my application.
@TasTuned5 ай бұрын
I’ve never tried an edelbrock but sounds like it works great on your setup! I like the idea of changing jets like that, I didn’t know they had that design
@Tk-ou9ec5 ай бұрын
@@TasTuned yes jets and tuning rods are changed from the top of the carb. The edelbrock is also a mechanical secondary but has a vacuum adjustable air valve at the top of the secondary Venturi. Once tuned properly they work flawlessly! It’s basically a Carter copy carb and many cars back in the day ran these from factory. A set and forget carb. If I ever get the money to change pistons and heads then I will go up to a bigger cfm carb as well but it can get quite expensive to do so.
@dazaspc5 ай бұрын
I would second that as well, I have used Edelbrook on Ford 302, Hemi 6, 360 and 318 Chrysler as well as 253 and 308's. It was a bit tricky on the 265 and the 253 but everything else worked great, the 318 and 308 worked perfectly out of the box. 3 stage metering like the Rockchester for good responce and part throttle economy. I used a 600/650 on everything but the 360 where I used an 850 from memory. Even put one on a mates 13B but it didnt like being mounted left/right instead of front/rear on the stock Mazda inlet manifold, We went to a Holley in the end for it a 450 with dual metering plates and center pivot bowls but still a vac.
@davehad-enough23695 ай бұрын
Quadrajet for street drivability and reasonable economy. Had the Holley on a WB Kingswood with the 5.0 4 speed and she was a thirsty bitch and nothing outstanding. Swapped out to the qjet and it was a different car. Snappy accelleration and when those secondaries opened it really lifted it's game. But you need a good qjet guy to set it up.
@holdenbrougham10568 күн бұрын
Rock Chester all day long ,, holly shit
@dirkdiggler57632 ай бұрын
For anything with a bit of work done… Holley
@Billskins4dayz5 ай бұрын
holley would be the go for ease of use
@TasTuned5 ай бұрын
Yeah I agree for the ease of tuning, I understand holleys but hands down the Rochester wins on economy and power in my experience
@Billskins4dayz5 ай бұрын
@@TasTunedfor sure be cool to see how they go dual plane v single plane intakes
@TasTuned5 ай бұрын
Yeah good idea, I’m always looking online for a single plane just to try but good ones for the early heads are hard to find.