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Posted: Mon Jul 17, 2006 9:07 am
by Greg Gordon
Barry, that rule of thumb is pretty accurate. I express is this way:

Horsepower after turbo/supercharing= Horsepower before * (14.7/boost in psi+1)

Lets plug that in, say a Verde motor with 150 rwhp has 5 pounds of boost. Ok it's (5/14.7+1) which is 1.34. Multiply 1.34 times 150 rwhp and you get 201 rwhp. Now SuperVerde has about 145 rwhp without the supercharger and 205 rwhp with 5 pounds of boost so you can see that this is pretty close.

This formula only accounts for the increased air pressure. It doesn't account for the increased temperature or the cost to drive the supercharger. On the positive side it doesn't account for the intake pressure pushing down on the piston or the increased effective compression ratio or other factors. Up to 9 psi these factors seem to cancel each other out so the formula works pretty well up to that point. Beyond that the benifits of boost will decrease. It would probably take 18 pounds of boost to double the horsepower.

Posted: Mon Jul 17, 2006 7:21 pm
by bteoh
Hey Mats,

What flaws have you found on the Gotech? Would that be for the MFI Pro?

Posted: Mon Jul 17, 2006 8:26 pm
by Barry
Greg,it works for me...thanks.

Posted: Tue Jul 18, 2006 3:33 am
by Mats
Gustav: I see no other alternative in that price range, I just think it's a pity you can't log witout a computer... :)

bteoh: I haven't looked at it for a while but when I was seriously looking into buying the stuff I read pretty much the whole forum they have at their website and wasn't wery impressed. For instance, they think it's a great idea to mount the intake temp sensor either by cutting a hole in a hose and just cram it in there or just at the front of the car by the radiator somwhere.. :shock:
Obviously the temp on a boosted car would be off by a mile but they think it's good even for a boosted setup (yes, I asked). And there is more like that, i guess its ok if you're only trying to get a motor to run like if it had poorly adjusted carbs but nah... not for me. :roll:

Posted: Tue Jul 18, 2006 6:07 am
by Greg Gordon
Mats, that's really an installation issue and not a flaw with the Gotech design or components. You can certainly drill and tap the plenum to mount the sensor. Or if you are using my intake the metal pipe section can be tapped and a sensor screwed in.

On a forced induction car using a speed/density injection system the air intake temp sensor should be mounted on the pressure side of the system.

Posted: Tue Jul 18, 2006 9:42 am
by Barry
Im impressed..a mate of mine did the exhaust for the spider today..Stainless as well,63mm. :D

Posted: Tue Jul 18, 2006 11:05 am
by Micke
Looks really nice. Except for the roll center (which isn't your fault really). Did you get the brake caliper paint from Jim????

Posted: Tue Jul 18, 2006 11:15 am
by Maurizio
Upgrade it with a watt linkage!
But all a waiste of time, a spider is for cruising.............. hmmm with this engine?

Here a lot of 105 guys run the exhaust underneath the backaxle.



to little time, need to get my spider out in the open air

Posted: Tue Jul 18, 2006 12:18 pm
by Micke
Watt, Pahnard, sliding block. Anything but this engineering masterpiece.

Posted: Tue Jul 18, 2006 3:23 pm
by Zamani
Brake caliper paint was from Bazza's excess nail polish. :lol:

By the way, I like the fuel line being under the car. The 75 (and I presume the Alfettas) all had it in the car. Pretty stupid IMHO. If you wore golf boots and smoked in your car you could burn yourself.

Posted: Tue Jul 18, 2006 8:29 pm
by Barry
Z,Did not know the 75 lines are in the car??Racing rules here stipulate the fuel lines in the car....I dont know whats worse,burning to death fast(lines in car)or burning slowly(lines outside)..All I know is we did everything possible to try and make the lines within the Gta`s as safe as possible...

Damn,outed again..my nail polish.. :D :D

Micke,roll center!! Its a spider ffs!!... :D :D :wink: Its made for cruising... 8)

Posted: Tue Jul 18, 2006 9:12 pm
by ar4me
I think the problem with lines underneath the car is the risk of rupture should you go farming in rocky area and then have sparks ignite the party. What I don't like about the lines inside the 75 is that they are "plastic". We originally did the fuel lines on the 3.7 as hard lines under the car. Later I re-considered and realized race cars usually have hard lines inside the car.
Jes

Posted: Wed Jul 19, 2006 1:57 am
by Mats
Greg Gordon wrote:Mats, that's really an installation issue and not a flaw with the Gotech design or components. You can certainly drill and tap the plenum to mount the sensor. Or if you are using my intake the metal pipe section can be tapped and a sensor screwed in.

On a forced induction car using a speed/density injection system the air intake temp sensor should be mounted on the pressure side of the system.
Eh, I know that, sheesh... :roll:

The problem is that even the GoTech dudes told me that they recommended that the sensor was mounter on the bumper, even on boosted cars. The Designers of the system says something like that, then it's a big issue for me as a consumer, tells me they know fcuk all really... :?

Posted: Wed Jul 19, 2006 2:42 am
by pancho
mmm, lancia beta coupe inside, gtv6 inside. 75's not sure.

I prefer the fuel lines inside, z how many times do you wear golf shoes with spikes that will penetrate the 2" of carpet and sound insulation - not to mention the 1.5mm hard plastic casing that the fuel lines have. :)

Posted: Wed Jul 19, 2006 5:54 am
by kevin
Barry, Exhausts look great, how does it sound?
Will swing by tomorrow, maybe we can tear up the neighbourhood with this cruiser. Are those calipers off a Maser?