408 W2 combo - where to from here

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evil66

evil66

evil66
Joined
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Hi guys,

Out here in Australia I am running a 408 / w2 combo in a 69 barracuda. Running a CRT 727 full manual with 3100rpm stall and 3.45 diff gears. Best run to date is an 11.9 @ 115mph with a 1.9 60ft.

Engine specs are:

408 stroker 360
W2 econo heads - standard 260cfm at 550 lift
W2 single plane inlet
10.5:1 compression
750hp Holley
Tti step headers / dual 3" exhaust
Comp 294 s solid flat tappet(248@50' 540 lift once lash considered)
1.6:1 rockers

The car is a street car and heaps of fun, just wondering what people's opinions are on what the next step would be to make it a bit quicker without destroying streetability, some say port heads because not enough port volume for 408 cubes, others bigger cam because w2 heads seem to like more lift, bigger converter, lower gears, bigger 1 7/8" pipes.

Car made 340hp at wheels at 5500rpm then fell away, so maybe 450 to 460 flywheel, wouldn't mind making around 520 to 530hp.

Thanks for any advice.
 
Greetings from a fellow Aussie!

What's the lobe separation on the cam?
 
750hp Holley >> 850 mechanical secondary. (750 might be a bit small considering the rest of the combo)
3.45 diff gears >> 4.10's (if not highway driven, will improve 1/4 times drastically)
find a way cut some weight from the chassis.
run it without full exhaust when you run it at the track.

just a few ideas for some gains.
 
Porting the heads is probably worth 3 tenths, converter would be another few tenths, steeper gears a few more....basically, between porting the heads, steeper gears and a converter swap, you should be able to get in the high 10.9's.
 
Where are you in OZ Evil66?

If it were me i would have the heads ported. How much tuning have you done?

Hysteric
 
Thanks for the replies guys. I am in Western Sydney and have had car at the mopar rumble the last two years, it's blue with 18" boss wheels on it.

Porting the heads is definitely on the agenda. I know the gears are a bit on the tall side but am trying to keep it a bit of a dual purpose car if I can, might look at 3.7 or 3.91 as a compromise, just wondering how far to go up on the converter to make it a bit quicker without destroying its streetability. Car is street driven every week or two but not a lot of highway driving, although it did 1100k return trip to mopar show a year ago.

Frosty - pretty sure it is 110 lsa but will check that.

Car weighed in at 1488kg or 3275lb at last drag meeting, with 28kg if tools and stuff in the car, really should have taken that out! Not sure where I could remove weight from besides changing to alloy heads, don't really want to strip car out interior wise.
 
I believe your 18 inch wheels and 3.45 gear isn,t much help at the dragstrip.More carb,cam and a better gear(atleast 4.10 with 18,s) should get you better times at the track.
 
evil66 said:
Thanks for the replies guys. I am in Western Sydney and have had car at the mopar rumble the last two years, it's blue with 18" boss wheels on it.

Porting the heads is definitely on the agenda. I know the gears are a bit on the tall side but am trying to keep it a bit of a dual purpose car if I can, might look at 3.7 or 3.91 as a compromise, just wondering how far to go up on the converter to make it a bit quicker without destroying its streetability. Car is street driven every week or two but not a lot of highway driving, although it did 1100k return trip to mopar show a year ago.

Frosty - pretty sure it is 110 lsa but will check that.

Car weighed in at 1488kg or 3275lb at last drag meeting, with 28kg if tools and stuff in the car, really should have taken that out! Not sure where I could remove weight from besides changing to alloy heads, don't really want to strip car out interior wise.
Click to expand...

Hey Paul, I know what you want from your car so I'm not going to suggest crazy gears or slicing out weight. I reckon you cam is probably as big as you want and keep it streetable so porting is definitely the way to go for a good start.. I also reckon 3.7 gears will help with those 18in wheels but I wouldn't go as far as 3.9s or 4.11s.

I'm not sure what your feeling are on nitrous but it's one of the easiest way to go quick on the strip without sacrificing street. You might need a blow down tube because the "boot" isn't really sealed.

I'll run some numbers through Quarter Jnr and see what it says.
 
flyfish said:
Porting the heads is probably worth 3 tenths, converter would be another few tenths, steeper gears a few more....basically, between porting the heads, steeper gears and a converter swap, you should be able to get in the high 10.9's.
Click to expand...

X2 that's what I would do....... Would have from the start. My brothers 408 in a 70 challenger best to date 10.7's with a solid cam and 1.5 rockers 850 double pump.
 
dont waste money porting iron heads...

you can buy alloy heads that already have better flow for about the same amount of money you would spend on porting.
 
$1000-1500 worth of porting versus $4k for a new head & intake combo. It doesn't make much sense to change everything. Remember this it mostly a street car.
 
In Australia having something in hand is worth a lot. I'd port those heads - not crazy - but you should be able to get another 20-30cfm at peak and more in the mid-lifts with a shop that knows performance valve jobs and porting. MP quality control is no better than anyone else and a port designed that well that goes 260 shows that...lol.
Get a camshaft that takes advantage of the reworked heads' flow. Then I'd replace the carb with an HP950, and look into a convertor that is more of a "double duty" rather than a low stall cruiser unit. I don't see you getting a full second without some serious parts changing with an eye to drag racing - meaning a good race convertor and steeper gears in addition to the safety stuff (bar/cage will add weight too). But you should be able to get another .5 pretty easy without losing much streetability.
 
moparlover said:
dont waste money porting iron heads...

you can buy alloy heads that already have better flow for about the same amount of money you would spend on porting.
Click to expand...

This statement is largely incorrect because the W2 head will port out and flow really well. The heads are capable of pushing a lightened car into the high 9's.
These are the only iron head worth porting for big power.

The W5 would be the first step above this head. Or the "Air Wolf" head. Not the Edelbrock.
The W2 will flow 20cfm over a Edelbrock head easy. Also, once you pay for the Edelbrock head, then port it, equipe it with the upgraded valve train, you'll have spent more on the head than simply porting out the W2!

You have a superior head now, just go forward with it.

The head once ported likes a high lift cam since this is where it will breath the best. Take advantage of this with a new cam, custom cut if need be. It really doesn't cost anymore than a off the shelf grind.

More converter is an excellent suggestion. Work your suspension next for a shorter 60' time. I like the bigger carb idea as well. Your cars weight is the next biggest issue. If it were possible to get it down to 3,000 lbs. , this would be the a soulute max weight I would want.

I know cutting 200+ lbs. can be a lot from a street car.
 
Yeah - I've got a friend over there and he drilled that into my head over the last few years...lol. In the US we tend to take the easy way out without realizing when you're not in the US, nothing's easy...lol.
 
I have 3.73 gears with a 9.5 inch converter that flashes to 4800 RPMs in my 69 Dart, car weights 3425 with me in it. The 408 in the car has ported W2s 10.4 compression, single plane intake, 950 HP, small solid roller, small TTi headers.
I drive this car everywhere, round trip to Vegas, back and forth to work three times a week[24 mile round trip] and Hot Rod DragWeek in 2012.
The best pass with the car so far has been 11.11 at 121MPH in FULL street trim on pump gas.
The 3.73 gear hurts drag strip times, car goes though the traps at 5400 RPMs.
I have since switched to 4.56 gears for DragWeek this year but both of our drag strips have closed down so I have not ben able to test the new gears.
 

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If you want to improve drag strip et and 60 ft time with street gears, consider slicks for strip that are sized to raise rpm at the finish line. Usual setup has large diam tire w low gears. Why not put on small diam tire that has good width to raise rpm. Then you put on the 18 inchers for cruising.
 
Thanks for all the feedback guys. Head porting is going to happen, possibly with 2.08 valve upgrade, aiming for around 300cfm at 600 lift.

The converter and gears is my next issue, possibly a newer converter that hopefully can be built with a bit more flash stall to get it up into the torque curve a bit higher, I don't think the current stall speed is bringing it out in the right spot with the single plain inlet after looking at some of the dyno charts on the rhs head article/408 combo done over there.

The gears, mine has an Aussie valiant diff with upgraded axles in it that replaced the 7 1/4 us diff as it was a 318 car. I might build up another housing with some 3.89 gears to try in the car if I can't find some 3.7s

The cam is a tricky one. I have been looking at a crane f256 with 256/260 duration and around 600 net lift with my 1.6 rockers to take advantage of the heads once ported, just worried that it might not survive the street miles being a sharper ramp/ flat tappet. My only other option would be some mrl solid roller lifters and a solid roller with just a bit more duration and around 600 lift?

Darrylsdart - thanks for the example, it seems pretty similar to what i am running with just a bit more in the gear/ carb department plus ported heads.gives me something to look at, what cam are you running?

3406pk - I looked at that idea but my 18s have a relatively low profile tyre and are very similar in diameter to my 26" street et slicks and hard to find a slick much smaller than that. Only option may be higher sidewall on the 18s next time I put tyres on it to make it taller on te street, shorter on the track.

Only other option is a set of indy 360-1 heads I was offered, non ported. This isn't going to be an easy upgrade cost wise as I will need to port them, new 1 7/8 ttis, have heard the supplied rocker gear isn't that crash hot and have heard casting quality isn't the best. The casting quality is my major concern.
 
Just a "for what it's worth":

My 410 stroker has ported Edelbrocks, cam is a small street roller of about the same size (248/254 duration), 10.8:1 compression, pump gas, 750dp, Victor intake, 727 trans, 8" converter that flashes to 5000 rpm, 4.10 gears with 28" tall tires.

I drive this car all over town, very "street-able" in my mind...but opinions vary....runs 10.80's in full street trim with mufflers.

I think with porting and a GOOD converter, you should be in the low 11's...add some steeper gears and you're in the high 10's.....Just my opinion.
 
It's losing a boatload of time in the first 60'. 1.9 60's are good for a mid 13's car. Get it launch is the biggest issue. Strokers with 3Kish converters can really move in the first 60, got to get it right on tuning the chassis.

If it's making 460hp, the MPH should be about 118 or so, maybe a little better at 3300ish pounds. Something is missing there.

Don't waste money on bigger headers, not worth anything in this combo IMHO.

Single plane probably isn't helping, not much in dual plane choices for w2 stuff.

IMO, the car is about .8-1 second slow right now.
 
Thanks fly fish, seems pretty similar to what I could do with mine if I step up the heads, gears and converter, would like low 11s consistent as will need a cage below 10.99 out here.

Crackedback, agree the 60ft isn't flash, best I can manage with the current converter, tyres and gears unfortunately and won't improve unless I make some changes, any suggestions for chassis tuning?

Scott - trying to keep away fron nitrous if I can, know it can make it a real dual purpose car like the blue vg valiant coupe out here in the90s.

Just worked out,race weight with me in the car varies between 3470 to 3550lbs depending on how much fuel so it's no lightweight.
 
what type of fuel system are you running?
If it was me a would just put a 100 shot of nitrous to it
 
Like most cars, I'll guess the front end is where a lot of time is hiding. Free movement, lots of travel, alignment, etc.

Better rear tires like a drag radial or slick would help tons. 18" DR's are out there
 
DarrylsDart said:
I have 3.73 gears with a 9.5 inch converter that flashes to 4800 RPMs in my 69 Dart, car weights 3425 with me in it. The 408 in the car has ported W2s 10.4 compression, single plane intake, 950 HP, small solid roller, small TTi headers.
I drive this car everywhere, round trip to Vegas, back and forth to work three times a week[24 mile round trip] and Hot Rod DragWeek in 2012.
The best pass with the car so far has been 11.11 at 121MPH in FULL street trim on pump gas.
The 3.73 gear hurts drag strip times, car goes though the traps at 5400 RPMs.
I have since switched to 4.56 gears for DragWeek this year but both of our drag strips have closed down so I have not ben able to test the new gears.
Click to expand...

Sorry for the hi-jack....is there a build thread for this car? If not how about putting one up???
 
The cam in my motor is [email protected] and .700 lift with 1.6s.
I agree with flyfish a good 8 inch converter is the way to go and that is one of the things I plan on trying.
My car should run better than it does, I just need to make some small changes to get it there. Like shifting at 7000 or so instead of 6500 [motor made peak power at 6600] and also getting the 60 FT time were they should be.
 
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