SOHC Times/power??

sbutler · 27-03-2005, 04:02 AM

With everyone spending big bucks on the boss motors:eg: bolt ons, edits etc.etc,to get into the mid 13s. Has enyone had a go at the SOHC BAs yet??
We stuck the Gtech in the Young fella's car the other day, & ran a few 14.5 to 14.3,
That was the best I could do. Since then, we've done a full twin 2.1/2 cat back, exhaust system & put some 18X8 wheels & tyres on.
So is there any reason this thing should'nt get into the high 13s???
Iv'e had a bit of a look at the stats, & the XT V8 is a bit lighter than the GT/XR8s so thats gotta help, although not having the top end of the DOHC motors. The rev limit is a bit of a problem too 5200rpm is a bit soon I think, the motor pulls well to the limit but you get to it to fast.
Is there any reason the limit is so low on the 3V compaired to the 4V motors? there basiclly the same bottem end..

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Racecraft · 27-03-2005, 04:24 AM

I dont think the XT got the same diff ratio as the GT/XR's so i'd guess that cancels out the weight advantage...

sbutler · 27-03-2005, 08:10 AM

Its the same as XR but not GT>>..

XA-Coupe · 27-03-2005, 08:22 AM

Steve, I wouldn't get too excited about a G Tech. I would swing the car down to the strip and see what it would do there.
Stock they are meant to be good for 14.9 ...dunno what the mods would do for it though.

SpoolMan · 27-03-2005, 08:39 AM

Quote:

Originally Posted by XA Coupe

I wouldn't get too excited about a G Tech. I would swing the car down to the strip and see what it would do there.

Echo what he said.
I wouldn’t post a G-Tech time, I bought one these things 4 weeks ago and used twice, it already has a new home...to many variables.

rodderz · 27-03-2005, 11:30 AM

Steve is your sons a manual or auto? The rev limit is certainly a negative of the engine, you have to work with what revs you have then. From the few drives I've had of the 220 motor it sounds very restricted so a decent cai and zorst would probably take the chain off its neck a bit.

From memory there was a bloke a while back from Canberra who had a manual XT220 who got zorst, cai and unichip at herrods, ended up with pretty close to 200rwkw or maybe a tad higher

sbutler · 27-03-2005, 12:28 PM

The Gtech we use showed us that it was dead right. Firefox used it, did about 5 runs. thay were all 13.6, then went to the creek and did a dozen 13.6s. Ive used it on my T3 & it was spot on the 13.5 I did at the creek. But I know what your saying though.
There is a lot of them that dont know how to set them up..
We've done the exhaust which opened the top end up a bit, it doesn't feel strangled at all now, & revs cleanly & strong, so that has worked well. CAI & K&N is next. We'll stick it on the Gtech in a couple of weeks to see what the gain is. But that rev limit!! is there anyone know why its so low????

BTW it is a manual....

rodderz · 27-03-2005, 01:39 PM

Quote:

Originally Posted by sbutler

But that rev limit!! is there anyone know why its so low????

Probably as it's usually found under the bonnet of F-150/250's etc! Spose ford wanted a really torquey thing to lug the effie's around and the long stroke 5.4 was perfectly suited to it having all that torque

FTe342 · 27-03-2005, 04:12 PM

Quote:

Originally Posted by rodderz

Steve is your sons a manual or auto? The rev limit is certainly a negative of the engine, you have to work with what revs you have then. From the few drives I've had of the 220 motor it sounds very restricted so a decent cai and zorst would probably take the chain off its neck a bit.

From memory there was a bloke a while back from Canberra who had a manual XT220 who got zorst, cai and unichip at herrods, ended up with pretty close to 200rwkw or maybe a tad higher

Yeah but thats on herrods dyno I wouldn't be taking that to the bank

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sbutler · 27-03-2005, 06:13 PM

Quote:

Originally Posted by rodderz

Probably as it's usually found under the bonnet of F-150/250's etc! Spose ford wanted a really torquey thing to lug the effie's around and the long stroke 5.4 was perfectly suited to it having all that torque

Would there be a reason not to lift it to say 5900/6000rpm or would be streching the friendship & the thing throw a rod out the side? This could be done with a edit could it not? & is the any reason the boss can rev to 6000rpm with no trouble???

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Bossxr8 · 27-03-2005, 08:02 PM

I don't think the internals are balanced properly like they are on the Boss motors, they are slotted straight into Falcons from the crate. Since FPV hand assemble the Boss motors they balance the crank at the same time, and if I can remember correctly the 290 goes a step further with the whole rotating assembly balanced as well. This will have something to do with it as would the limitations of the heads. I think the power would drop off after 5000rpm so it may not be worth revving them out, as said earlier they are truck motors designed for low and mid range torque.