m21sniper

Thanx dude.

DR

>Actually yeah, that would be cool.....

Scariest ride of my life was in a Pinto stuffed with a 351 with a 6/71 blower on top of it and a Lincoln locker.....in downtown traffic in Asheville, NC!

m21sniper

Buddy of mine had a Big block Vega(427cid IIRC).

LOL, that thing was scary.

atb

Good power to weight ratio always makes for a fun ride. Scariest ride I've seen ( I wouldn't get in the car although I was offered a ride) was a VW bug with a mid mounted Toronado 455 w/transaxle driving the rear wheels. Nasty!

jeff jackson

The real problem I see with turbocharging the 928... (other than installation logistics for both turbos, connected via adapters bolted to the factory exhaust manifold outlet flanges, and adapting to appropriately sized turbos of approx. 300 to 400 cfm per side)... and the intercoolers,... envision side mount intercoolers, mounted in the brake rotor cooling ducts, similar in concept to the Mitsubishi 3000GT VR4)...is the 10 to 1 or better compression ratio, of the 85 and later 928 engines. I don't care what sort of turbo, and intercooling, you provide for this configuration...even with the superior breathing of the 4V cylinder heads...add boost..., even <10 psi...and cylinder pressure, combined with the increased intake mixture temperature, is going to yield detonation. And remember...the 928 engine was originally designed as a high performance, "naturally aspirated" engine. So...these extreme cylinder pressures and temps, were NOT included in the OEM engineering concept for this engine. So...without radical reduction in the static compression ratio, prior to adding "turbocharged" boost...Detonation, and piston / valve problems, (due to "knock"), are certainly likely. Increased intake mixture temperature, under even moderate boost, will yield cylinder pressures and temperatures far in excess of OEM design criteria. Water/alcohol injection might help..but think about it...with th quality of fuel currently available, unless a "purpose Built" (read LOW COMPRESSION), short block is put together, the OEM engine ISN'T at all well suited for turbocharging. Without substantially changing the OEM designed "concept" for this car. That is...no AC...high octane fuel requirements...fabbed turbo and intercooler installation, supplemental fuel management. etc. Don't get me wrong, I feel turbocharging is a far superior means of HP production than supercharging. My point is ...with a car like this one, a "purpose built" motor / fuel management system is highly desireable for turbocharging, vs. a basiclly straightforward "bolt on" type install for the supercharger. So... go where your heart and your wallet leads, and happy holidays

Imo000

And you don't think every boosted and non boosted 928 owner knows this? What is the purpose of this post?????? I tell you what purpose built is. To get the most amount of FUN while not going broke and not necessarily in that order

How's your "purpose built" project coming along?



P.S. Happy Holidays to you too!

hacker-pschorr

Tell that to the 30+ Murf928 owners out there who are having the time of their lives with 400+rwhp.

Barry Johnson

Wasn't the "10:1" compression ratio disproven to be closer to 9.6 or 9.4:1? There was a thread about that some time ago...

Chris, if you wanna drop the cash on it, get the GT30. Ball bearing, and should provide 8psi pretty quick! Thats just my opinion
I think you should be fine with regular aluminized steel exhaust pipe with 8psi and no intercooler. If you really want, you could take an intercooler from something like an Audi A4 and see if you can fit it up front, or just run it inline with the piping under the car, that would be cool...

Imo000

There is a problem finding a suitable A-A OEM intercooler is to fit a boosted 928. 99% of the OEM ICs have inlet/outlets of 2” or less. In most cases, in mine too, the piping is 2.5” or larger. There are only a very few OEM ICs that have 2.5” In/Outlets. These intercoolers are the Volvo car, the small NPR (Isuzu truck), and that’s about it. All the turbo diesel truck (GM, Ford, Dodge) ICs are huge, way too big to fit the 928. Unfortunately all the Audi/VW ICs have less than 2” In/Oulets and this goes for all the other factory intercoolers too. I’m contemplating between the Volvo or the NPR. The Volvo has a very large frontal area and since I don’t have the condenser in front of the radiator this might work. The small NPR IC is almost too wide, but it might be the best candidate for a boosted 928 that still has its AC intact. The NPR IC is very hard to find since most of them are the large units. The Small ones were only available on the ‘91~’93 Isuzu trucks. On the other hand, e-bay has a good selection of generic A-A ICs for around $200, that should work with little effort on most applications, but they are not OEM. And as such, their quaintly might be questionable. Although a lot of DIY builders on the turbomustangs.com board have used it with success.

atb

Jeff wrote:

Sometimes you've got to take a risk and believe that the world is not flat and is actually round. Luckily, the 928 crowd has the likes of Tim Murphy who was willing to test the boundaries of such things in light of the general belief to the contrary.

Jeff, five years ago I think 99% of the people on this forum would have agreed with you. Now, 99% will disagree. On paper the 928 motor may look like it isn't a good boost candidate, in application it does very well.

porshhhh951

yup it just takes someone who other people believe in to do it and then others now believe.

it will be the same with turbochaging for your group. It will take a coule individuals to make some kits and see the great results in powerband and peak #'s over centrifical units that a company will start to see a market for it for the 28 community and then come out with a turbo kit for the masses at a affordable rate.

Everything just takes time.

Imo000

You see, affordability is what everything comes down to. In my case when compared to other non IC kits, I get 80% of the hp BUT at 5th of the cost .

Centrifugals are always more affordable than any other method of boosting. I predict at the end, Turbos will be the least affordable. This is mainly due to a TTs complexity and sheer number of parts.

porshhhh951

they will be the least affordable but, most effective. For someone who is looking for results they will go turbo. Or roots.

centrifical will and will always be for people who are on a budget and just trying to get some hp.

There are some centrifical kits out there that are just as expensive as a turbo kit even...thats whats funny. So there is a expensive way to go centfifical too.

Imo000

True, but you are comparing base turbo kit with, for the lack of better word, a ” fully loaded” Sc kit. Centrifugal superchargers will always out sell the turbo. They are cheaper and simpler to install. Simplicity is a major factor in states like CA, where the car needs to go back to stock to pass the emission test. You are not giving enough credit for the centrifugal SC. They are great and a lot of 928 owners would be more than happy to have one.

Theoretically, N2O is the most effective way of boosting the hp. With the proper setup, it can produce a dyno graph fat enough that even the turbo guys would be envious of. The main disadvantage is of course the constant need to refill. Every single boosting technique has its advantages and disadvantage.

Imo000

How can you imply on that the centrifugal Scs don’t produce a result? There are cars putting 450 hp to the ground. If that’s not a result that I don’t know what is.