Beating a dead horse - 4.5 liter power
05-28-2005 | 07:11 PM
#46
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Joined: Dec 2001
Posts: 25,152
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Originally Posted by John V
Any idea whenyou think you'll be able do test your work?
It was supposed to be over christmas....
BUt then I decided to paint the 78 before I put the new engine in. Then I tore out the interior. (any similarities seen from those in the know to my 89?) I'd say July. I really need to get this finished, and soon.
05-28-2005 | 09:34 PM
#47
Rennlist Member
Joined: Feb 2003
Posts: 29,956
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From: saratoga, ca
There are a lot of advantages to the GM product. mostly a more advanced combustion chamber as well as intake. keep in mind, the 7200rpm rev is not where the peak hp is for that engine, as i believe it is in the 6300-6500rpm range. this means to get maximum hp to the wheels through gearing, you need to shift 500-700rpm higher depending on gear spacing. (ie if your peak was at 7200rpm, you would need to shift at 8000rpm to get the full use of that hp.) I think when you see what we are doing with the N/A 928s , its pretty amazing . my 243 rear wheel hp (from 175 to 243 with no mods and 150,000miles) from a 2 valve 4.7 liter (think ford 289ci) and then my 275 to 293 rear wheel hp from my 4.95Liter part euro 2 valve (think 302ci) and not the holbert car at 335 rear wheel out of a 302ci 4.95liter, is pretty phenominal.
there are many mustang supercharged cars that barely put out this kind of power!!! And, all out of engines that were 15-20 years old !!!!!!
And, just going to a 6.5 liter gets you to 400 rear wheel with not too much effort modifiying anything besides displacement. (ie 390ci) not bad!
your not going to get 260 at the rears with a 4.5 and some head work, but i bet 240 is possible with some trick work. The '78 cam does look to be very close to the euro cams, but without the lift. im sure with some real race cams, some trick intake system, 260-300 rear wheel could be possible.
MK
there are many mustang supercharged cars that barely put out this kind of power!!! And, all out of engines that were 15-20 years old !!!!!!
And, just going to a 6.5 liter gets you to 400 rear wheel with not too much effort modifiying anything besides displacement. (ie 390ci) not bad!
your not going to get 260 at the rears with a 4.5 and some head work, but i bet 240 is possible with some trick work. The '78 cam does look to be very close to the euro cams, but without the lift. im sure with some real race cams, some trick intake system, 260-300 rear wheel could be possible.
MK
Originally Posted by John V
Brendan,
No secret... I hope you get all of that and more!
I guess with the lack of results I'm used to seeing, I always temper my expectations to avoid dissappointment. I'm rooting for you but 260 RWHP would be phenominal from 4.5 liters normally aspirated! That would be 305 crank hp using 15% driveline losses. To put that in perspective, the new GM LS-2 engine program set a goal of 1hp per CID of displacement. That means that our 20 year old engines would need to be around 270 crank HP or 230 RWHP to be on the same disalcement to power ratio as one of the most advanced passenger car engines on the planet. Further, those engines are 7200 RPM which gives them an edge in peak HP production. Granted, they are doing this with cam in block technology which makes it that much more impressive but, the fact that this power level appears within reach for us is impressive.
Any idea whenyou think you'll be able do test your work?
No secret... I hope you get all of that and more!
I guess with the lack of results I'm used to seeing, I always temper my expectations to avoid dissappointment. I'm rooting for you but 260 RWHP would be phenominal from 4.5 liters normally aspirated! That would be 305 crank hp using 15% driveline losses. To put that in perspective, the new GM LS-2 engine program set a goal of 1hp per CID of displacement. That means that our 20 year old engines would need to be around 270 crank HP or 230 RWHP to be on the same disalcement to power ratio as one of the most advanced passenger car engines on the planet. Further, those engines are 7200 RPM which gives them an edge in peak HP production. Granted, they are doing this with cam in block technology which makes it that much more impressive but, the fact that this power level appears within reach for us is impressive.
Any idea whenyou think you'll be able do test your work?