Imo000

Or if you are handy, for $1000, build an SC setup like mine (easily doable in 2 weeks) and have about 400-425hp too.

Imo000

With a set of Authority clones I dropped down from 13.7 to 13.5 sec. If he gauges his performance to the FZR, it ill take at least 550hp to get there.
However,before the SC, I had a go against a couple 600cc sport bikes (late model ZX6 and CBR 600), above 100mph, they couldn't pass me. These cars, evne near stock form are not slow, especially on the highway.

RicerSchnitzzle

Wow, I hadn't even double checked the graph... Every one of the engines Jegs has from Patriot have the same issues on the pop up dyno chart. I'll be calling them tomorrow to see if they have a real dyno chart. Peak HP/TQ may be correct, but the graph is obviously bunk. Thanks for the save!

Still doesn't kill my plan, but I will proceed with a tad bit more caution.

IcemanG17

true...BUT its still heavier and increases the oiling issues inherent in the 928 engine by increasing crankcase pressure.....

ShawnSmith

If I wanted to simply have cheap hp, I'd have bought a GTO and souped it up.

Or maybe a WRX.

I wanted to do it a little different than most folks. No chevy motor for me, thanks.

tailpipe

hmmmm my friend has an old cady 500 collecting dust in his garage anyone have an early 80s parts car they would like to part with cheap ? thumbs up to you project man in the end money talks and its your project the only one it has to please is you.

GlenL

I've got an Olds 455 in mine. I'll admit to taking a tape measure to it the last time I needed a rebuild. It'd fit.

Something to consider is that these good ol' American iron beasts produce huge torque numbers and will break the 928s dainty transmissions.

danglerb

Generally 928 owners are way too nose to tail, its good to have people doing something new.

S4ordie

Can anyone confirm that this conforms to all 50 states? How would CA reconcile a completely different drivetrain? To pass is to run clean under load as well as visual inspection.

This phenomena is deja vu. In the late 70's a few people started replacing the 6 and 12 cyl Jag XJ's with 350 CI Chevy engines and trans. I loved the looks of those cars but the gremlins, maintenance cost and parts could empty Bill Gate's wallet. The conversions worked well, passed smog, then, and indeed improved the perfromance and overall enjoyment of a classic un-repeated design.

My take is this. Those Chevy conversions saved a whole lot of cars from the wrecking yard. Much like our 928's they were readily orphaned and only the most committed enthusiasts were able to maintain the original configuration cars. I suspect there were more Jags on the road because of the conversion compared to if the cars were left stock and abandoned.

I like the notion of a full turnkey GM drivetrain and electrical conversion kit. I suspect someone could do it a few times and figure out how to do it right and affordably. There is no question more Sharks would be saved which I think would increase the values of the cars owned by the purists. So I give this a thumbs up.

I would be very interested to find a turnkey business for our cars. I can assure you I would entertain that option for a good condition car with TBF. Same or better performance, lower cost of ownership and greater range of options. Someone's gotta do it.

Here is a link to Suncoast in Florida. They have been doing Jag conversions for more than 20 years.

http://www.suncoastconversions.com/

RicerSchnitzzle

It's not immune, there is still a chance in a high G situation to flood the bowl resulting in bog coming out of a turn. But it's drastically reduced. A road race float for severe duty is much like a circle track float except it's modified on both sides to prevent the effects of slosh bouncing the float. It's the slosh that causes more problems than the g-force itself. Many manufactures make them including Quickfuel, Barry Grant and Holley.

When used with larger needle and seats and lower fuel pressure they prevent over filling of the float bowls in the corners. This makes for better throttle response off the corners.

It's simply an improvement that gives decent results. It's very popular with offshore carb set ups as well since it helps fight the effects of slosh.

danglerb

What Chevy would have to do is EPA certify the whole system to current standards. Calif engine change rule is that you can swap the complete system from any same or newer model year Calif car, and if it passes the BAR referee station inspection you get a sticker on the door jam with a bar code and forever after its tested as if it was the donor car.

Chevy did something like this before with the ZZ4 I think engine.

That said I think you still might be much better off using an earlier donor car and related parts.

Larry Velk

Very good and interesting points. In fact, the bike deal is why the car feels slow. The E-type is now only in a few thousand pieces as it is going together. A 928 is pretty smooth and, at least our '86, needs a few rpm before it wakes up.
Now some thinking on 928 performance in general, namely what can be "wrong" with a 5.0 liter which runs 'normally'. The cams could be off, it could have weak cylinders (various reasons) or a clogged exhaust. Almost all other problems aren't likely or even possible if the car runs normally 'by the seat-of-the-pants'. Solid state engine control is pretty much go-no-go. I get 22 mpg or so on the highway, it doesn't miss and it will rev to proper levels. Two hundred ninety horse or so just isn't very much in a 3 600, lb car. Our 951 is chipped (effective with turbos) and might be 250 hp with 2 800, lb. It is quicker - maybe 11.2 lbs/hp vs. somewhere in the 12's. I like our 928 and I'm not into bench racing arguements, I just don't like having hundreds of useless parts spinning around not doing anything except looking cool. Old Chevies had tin valve covers that leaked with their 4 little bolts, but the oiling system worked.

GlenL

Right. Some people complain it's not fast off the line but it's not designed for stop light races.

Actually plenty. That's a 23 year old car.


No bench racing? (lol) Well, your 951 isn't a 2800 pound car unless it has been lightened and your 928 isn't a 3600 pound car unless you've got bricks in the back. The turbo "might be 250 hp?" Sure, I guess.

You could learn a lot about your cars with a trip to a chassis dyno. It's pretty cheap for discovering if the cars are really running to their potential and the A/F readings can be enormously instructive.

I'll wager that cleaned injectors, new spark plugs, a new O2 sensor and new air and fuel filters would make a marked improvement in your 928s performance. And check the vacuum lines, plug wires, etc. It will be an exciting ride if it's running well.

hacker-pschorr

430hp, that's its??? Stock non-ZO6 C6 Vette's are putting down 400rwhp with an exhaust and cam change from only 5.7L

Not if it's tuned correctly, but that discussion is for a different thread.

Funny how Todd's 30psi engine that is stock except for 951 pistons has less blow-by than most stock 928's running around.

Larry Velk

Good advice on the chassis dyno. I did go to a local one and saw Olsen's and Hackker's on the dyno. I think "Murf" was there also but didn't run while I was there. A few clean 1/4 mile times aren't a bad measure either as trap speed can be a rough guide to hp, even if you can't launch. Mixture info would be great. My 928 has under 60 k, I'm the 3rd owner. I did wires, plugs, TB, air filter, fuel filter and a relay or two.
When I worked at the Chevy garage in the 70's we did have some collapsed downpipes - they were double wall, the slush would hit the hot pipe and collapse the inner wall. I wouldn't doubt my cats may be a little "full", but other than that, the car is at least somewhat OK. Maybe if the Green Bay guys go to Appelton (or wherever that was) again, Ill give it a try. I heard at a local speed shop (buying trans coolers for my overworked Merkur autos) that Jean Louis used their dyno, so 928's are getting strapped down all around Wisconsin. What I shouda done was raced Hackker's 2-valve.