Took my car down the drag strip last night and the was a bit surprised at how little top end speed the car had. The car pulls awsome burnouts and has the getup and go to rival most cars there but once i hit round about the 90kph mark the balls just seem to drop out of it.
the car was running high 15' all night which im told was really good for that car but i wouldnt mind seeing some more go in it. my mods so far are only minor thing but would like to know a few more before getting into the big stuff ie turbos etc.
my mods performance wise sofar are
High flow cat+2 1/2inch eshaust+sports muffler (no res)
blitz air pod with heat shroud (battery box was shifted to boot so pod has plenty of cold air)
topgun plugs and leads
also pull out back seat and spare tyre for weight.

any other tips would be really helpful

sorry mate i wouldnt have many tips for you other then change cams etc, all the internals?
im just interested what kind of car do you have?

my cars a manual with more mods than yours and i only run low 16's; so i am skeptical but that stall converter in your profile might do the trick. The problem is the 12valve; can't breathe at high rpm; i believe the auto gear box with the overdrive is pretty gay too....

what dragstrip did you go down by the way, willowbank? does it usually have friday night runs; read queensland in your profile too

this was at the Bohle drag strip near townsville
the car is a kr verada, and the stall converter is only to two and a half grand(though i believe a standard magna one is one and a half grand).
the car ran pretty consistent 15.89/15.97s all night went for about six runs.
would like to see what the car would run down south in the colder weather, when i did the runs it was still 28degrees at 9:30pm

WTF!!!!
hell thats not bad! maybe my auto could get there one day :shifty: :think:
maybe get the engine bored out a bit more..

Thats not f**kin bad at all man!

Umm... i dont think the standard magna stall converter is at 1.5k coz i'm able to get mine to 2k... didn't try any higher coz i didn't want to overheat the converter.

What tyre pressures are you running? maybe increase the rears to 38psi and front to 32-35. (assuming you can get traction off the line)
Also try advancing your ignition timing and wrap you're intake pipe and fuel lines with heat insulation wrap. Thats if ur after cheap mods.

i'm afraid if you want better performance at higher speed theres not too much you can do with the auto coz of the **** ratios.

Next suggestions would be extractors, TB & ported intake, port & polish head and longer duration cam.

what speed did you go threw at bud

I find my 6G72 breathes just fine in the top end. It's really rev happy and loves to see the redline. I ony have a K&N Panel filter in the stock airbox, and a Redback Cat-Back muffler.

I'd have your exhaust checked out, especially the Cat. If the car has been gently driven, you'd be suprised the amount of crap that the Cat catches. If you drive them hard, the cat gets hot and burns all that stuff away.

Reading your profile, do you have extractors, or just a performance exhaust from the factory exhaust manifold back? It's a little confusing to me, that's all.

I'd try a K&N panel, and possibly a set of extractors for it too. Ask EzBoy how he is going on his 6G72 extractor development.

After that, you are talking head work, mainly porting & polishing. Won't really need that much done, the main thing is to get it match-flowed on a flow benc, attention paid to opening the exhaust port flow by a bit more than normal, and then just smooth off the dags a little all around. A slight swirl on the inlet side wouldn't hurt either :D

You may also be able to shave the head down a little to increase compression too while the head is off. It would also be the perfect time to put a wilder set of cams in it - stage 1 sort of level.

Any mods past that level will require aftermarket ECU like a Haltech that Ego has, or possibly a Greddy e-Manage. This will need Dyno tuning as well.

the exhaust includes a high flow cat 2 and a half inche pipe and a sports mufler, from the manifold to just before the cat is stock. i was informed by some of the guys at fast fit that the manifold to the cat being replaced with extractors while giving a little more top end would not justify what i would loose at the bottom end torque. Apparently the stock components arnt that bad. The exhaust is only six months old, i dont know how much crap can get in there in that amount of time.
the engine itself has only done about 9000km's since a full rebuild.
top speed on the quater is usually about 86mph
shoulda seen the look on this guys face, he was driving a vn ss commodore but he didnt start pulling away from me till about the 250m mark. think he ran a 14.9

that time would be right if you can get off the line quicker than my car can, i was running 133km/h, if you go out to willowbank at all let me know.

ps mitsimonsta your 3rd gen is 24v our only 12v, main reason why lessor top end.

you want top end; be like me and search for quad cam 24v, thatll give ya pleanty; except dont take an engine i wanna buy

ps what 60ft time?

oops, my bad re: valves. Didnt some second gens have 24V V6's?
Just do a KB and drop a DOHC 24V in, that will fix alot of your problems. You'd beat that VN SS by a couple of lengths. Expensive though.

Still a 'stage 1' match flow port and polish should help big time. Extractors and K&N panel will also help alot more. Those exhaust manifolds are very restrictive and although you may lose a little low end, a well designed set will try for an absolute minimum. I think you want a longer tube to increase torque potenital, but EzBoy will correct me if I am wrong.

Without resorting to surgery on the head, you can only do stuff like porting of throttle bodies, trying to get cooler air to the airbox, nothing major, but could give a small gain, r help with smoothness of delivery, that sort of thing.

Can you put just the DOHC head on your block, or is it not compatible? I'm thinking along the lines of the VL brigade putting RB26 heads on their RB30's...

easier to just transplant engines.

Yeah nowadays the conversion is very viable; if mechanically minded expect around 4k to drop 1.5 seconds or so.

That as opposed to goin 900$ extractors, 500$ throttle body, 2000$ on wheels, 200$ on filters, 150$ on ignition; all adds up then you might drop .5seconds.

You other other is as stated flow in heads and change of cams and manifolds

My 60ft time was 2.321sec
another mod i didnt include earlier was to remove cooling lines going to tb
tyres were 15inch steelies with 235's (had a bit of rubbing trouble on the tight corners)
Would like to know best way to port the tb as i could probaly do it at work.

Extractors should be closer to $700 fitted.

Throttle body $90 from EzBoy

$120 for K&N Panel

I didn't mention ignition or wheels.... but yes some wider wheels will help - 17x7.5 should be enough on a 6G72 'Rada unless you are going for the DOHC obversion, then look at 18x8 or so. Ignition should only be chased if you have an ignition problem.

Also against you is the extra weight of the 'rada, more sound deadening and other heavier materials.

I still think at this stage, extractors will give the most benefit, followed by a K&N.
Head work is then your next option., but will cost you $1500 before you blink, $3000 if you want to do the cams & roller rockers etc. Remember you have head gaskets & bolts to pay for as well, I'd also do an oil change and coolant flush & fill afterwards.

I doubt you would see any gain from a monster plenum like Ez has made up for his TF... especially if your restriction is in the head and exhaust manifolds. After some head work is done, it would vertainly be worth it, but by that stage you are talking 'buy a DOHC & swap it in' cost territory anyway.

yep im was just talking what had to be spend on my car; well past a dohc conversion....

yeah my 60ft's 2.381 rebuild would be doing it well too; mine probs needs one

Well ran into a bit of bad luck this morning and lost 2nd and 4th gear in my tranny, should have it fixed/ rebuilt by thursday. Found out that the coolers fitted to all magnas are actually to small so will be replacing it with a larger one as well. shouldnt set me back anymore than $2000 as i will be fitting and removing tranny as well as cooler myself.

Your best bet for top end is the DOHC conversion without a doubt.

I had done extractors and a 2.5" mandrel bent cat back with a lukey LR2779 muffler on my old SOHC 12v and it had absolutely nothing on the DOHC in the top end.

Bottom end is practically the same, the SOHC may have a little more actually, all it is though is that whilst the DOHC has more power, it peaks in a higher rev range, so gear choice is more critical in a DOHC than a SOHC, especially in a hill climb.

With the right gear choices I keep up with my mate's modded EL V8 Manual Fairmont Ghia (he converted it to manual himself) up Springwood Rd, which is quite steep and tight.

And keep in mind my DOHC is running a STOCK american diamante ecu tuned for an auto. The only mods I have are extractors and the same cat back as was on my SOHC 12v. I went from about mid/low 16's to 14.8 over the 1/4 mile and that was just my first run without actually knowing how to launch it properly on a strip.

I'd be searching for a DOHC 24v 6G72 if you can.