Upgrading/increasing HP - Any recommendations ?

[8bender]

Hi Guys

I would like to increase the HP in my 84, 928.
I don't want to go crazy (opening the engine,headers etc).
Any recommendations?
THANKS

Neil

[Cajundaddy]

Ls3

[8bender]

Ls3?

[Mrmerlin]

sell it and buy one of my 85 Euros ,
I have 3 for sale,

they all have 310 HP or more,
2 of them have headers.

one has a 5.0 liter block ,
one is a 5 speed,
and two are autos
The Swiss auto has ABS
sorry for not posting prices
Blue Swisss auto fully sorted with ABS 15000.00
Black auto 5.0 L tan seats solid DD 7800.00
Blue 5 speed just finished cream of the crop 25000.00

[curtisr]

Originally Posted by Mrmerlin

sell it and buy one of my 85 Euros ,
I have 3 for sale,

they all have 310 HP or more,
2 of them have headers.

one has a 5.0 liter block ,
one is a 5 speed,
and two are autos
The Swiss auto has ABS

As per guidelines we need prices.

[harborman]

For the amount you would spend in time and money, it's not worth it. The biggest bang for your buck if you want a real go faster is a Z07 Corvette. But you will be driving a rather common car, not a 928. Enjoy the 928 for what it is and not try and add 30 years of technology to it.

[8bender]

Guys

Please read my post.
I don't want to upgrade headers,open the engine and nothing crazy etc.
For sure I wont switch the engine.
I was thinking more about exhausts systems ,K&A filter kits (if there are) etc.
Prices will help Mrmerlin

[Cajundaddy]

Originally Posted by 8bender

Guys

Please read my post.
I don't want to upgrade headers,open the engine and nothing crazy etc.
For sure I wont switch the engine.
I was thinking more about exhausts systems ,K&A filter kits (if there are) etc.
Prices will help Mrmerlin

No significant HP increases to be found here. If you want real juice, you gotta spend real $$$. On your budget, the greatest performance improvement would be quality tires.

FYI: LS3 is a Corvette crate engine, 430 hp for about $10k all in.
LS3 Crate Engine - Race Engine | Chevrolet

[harborman]

Originally Posted by 8bender

Guys

Please read my post.
I don't want to upgrade headers,open the engine and nothing crazy etc.
For sure I wont switch the engine.
I was thinking more about exhausts systems ,K&A filter kits (if there are) etc.
Prices will help Mrmerlin

Just keep it tuned, no K&N filter, stock one is plenty. New Plugs, rotors, caps, Techron in the tank, good tires, shocks, brakes. These cars are old, no need to spend a lot to gain 10 HP If that. Enjoy the car for what it is.

[JK McDonald]

Hey 8bender - The HP ratings have never been a strong point for the early U.S. 928 models. Although I have always kept Miss Purdy (84 928S) tuned and in tip top condition - plus an especially thorough once over just prior to any out of town trips, a serious boost in HP would be a welcome improvement.

Like most 928 owners, we're often the leader of the pack out on interstate and perform fine over most mountain passes. But, when I was into some of the steeper back road twisties of the North Carolina - Smokey Mountains, she was breathing hard just to stay up with traffic. Of course it didn't help negotiating a blind switch back while trying to stay out of the way of the locals who were obviously familiar with every bump in the road. At times their advantage really kept Miss Purdy huffing and puffing when exiting a tight curve and passing my own back bumper. It was especially dangerous at night since NC doesn't seem to waste much money on guard rails or paint for signs posting a suggested safe speed along the edge of many of their dark two lane roads.

If there are any secrete formulas (short of an late model LS transplant) that boosts our HP please post the information - Miss Purdy is definitely in need of some help

Michael

[Danglerb]

The way Porsche has ALWAYS sold cars to their limited customer base is to release each new model with the least HP they can get away with and bump it up every few years. The 928 is typical, the exception being the Euro S models which had the go from the start.

Early cars have no cheap path to more hp. Making the exhaust louder makes it seem like more, but its not real.

Gains are possible just from the exhaust system, but not exactly cheap, or large due to the rest of the engine and intake limitations. Several variations on an X pipe have worked well, more so when used with upgraded exhaust manifolds, true headers or 85/86 manifolds.

Without opening a can of worms, early 5 spds are a LOT more fun than the AT.

[Plexus928]

Originally Posted by Cajundaddy

No significant HP increases to be found here. If you want real juice, you gotta spend real $$$. On your budget, the greatest performance improvement would be quality tires.

FYI: LS3 is a Corvette crate engine, 430 hp for about $10k all in.
LS3 Crate Engine - Race Engine | Chevrolet

Thanks for the link, definitely in top 3 for my current project. (not a Porsche)

[JK McDonald]

Hey 8bender - There ARE a few parts from the early Euro- Version 928's that some owners have cross bred into the U.S. models in search of better performance. But most of these mods require a lot of expertise in knowing what adds HP without building a ticking bomb under the hood. Like others have mentioned, without a major pile of money to invest and knowing how to properly spend it on your current 928 - you'd probably do better just buying a vehicle (Like one of Mr Merlin's Euros) with the level of performance you want right out of the box

Here is a photo of Miss Purdy catching her breath idling and cooling down with the radiator fan running full tilt at the 4k foot mark on the "Blue Ridge Parkway". I have added a toggle switch beside my seat to turn on the electric fan early if the temp gauge heads too close to the 3/4 mark. The main problem you have is that the speed limit is 45 mph and the cops watch over the BRP for violators very closely. There were a couple of Beemers and later a Miata that kept me looking over my shoulder most of the day. Another 100 HP kick in the pants to help climb some of those 5,000 foot North Carolina - "Going to the Sun" grades would have been nice.

Michael

[Mal81]

Why do you want the additional HP? Do you have a manual transmission (I think a manual transmission makes it a lot more fun to drive). How is your compression? Maybe it's time to replace some gaskets. Fuel injectors flowing well? Spark plugs in good shape? How old are the ignition wires.

I often hear people wishing for more power (from a 35 year old 8 cylinder aluminum body car?); I wish I could have new carpeting, a couple of dents removed, and a little better headroom, but more power? It's hard enough keeping the rear wheels planted as it is... Unless youre racing, I'd look to maintaining what's there before anything else.

[8bender]

Thanks Guys
We always want MORE HP no matter how much we have , dont we Mal81?
But I do agree.
Thanks again

[JK McDonald]

I was just agreeing with 8bender's initial comment that the 928 could use a HP upgrade. The stock drive train in Miss Purdy is an automatic but in great condition - just at 100k miles, Runs crisp, Complete Recent Tune-up, Rebuilt Injectors, Fresh Oil, No Engine or Trans leaks, No-Cat high flow exhaust and driven with a heavy foot when possible. For me it seemed that the issue was that the well monitored 45 mph speed limit on the BRP kept Miss Purdy at a disadvantage. You just couldn't get a run at many of the upcoming 5 mile 16% (?) grades. I think there is a real U.S. MPG gearing-dead spot (?) that is right in the middle of the torque range and I found it a bit difficult to sometimes locate a balance between the allowed Ground Velocity, Engine RPM and the Linear Momentum of the car.

After seeing several cars in the approaching lane with a lit-up police car behind them I asked a lady at a tourist information center what was the "accepted " speed limit. She just smiled and said a speeding ticket in the park is considered a federal crime. Like I had mentioned earlier - what really kept Miss Purdy on her toes was that the locals all seemed to know when to drive a little more aggressive and where to have their engine pre-torqued for an approaching blind curve.

For the year, I don't think she is a slouch but a standard transmission and an additional 100 HP to pull out of my hat would have probably helped.

Michael

[Danglerb]

Nothing cracks higher altitude like a turbo, elevation meant nothing to my 944T, but seriously nerfed all the NA cars, even big V8's.

A slight gain in HP is a very temporary fix, you get used to it in a few weeks and you are right back where you started wanting a "little" more hp. Its best to set a serious target and make ONE step.

While I'm at it I will also disagree with the drop a chevy in it idea. Less than 20% of the engine swaps end up finished keeper cars.

[Pete R]

Michael
[/QUOTE]

Is it just me or does this car have an minivanish aspect ratio on those tires?

[JK McDonald]

Hey Pete - I think you're right about the look of my mini-van tire profile . I have tried a couple of different sets of 18" Michelin and Yokohama Touring Low Profile Tires, an assortment of different shock combinations and after market wheels trying to find a compromise in looks, performance and ride comfort without much luck. When traveling I often switch back to my old Gomer Pyle stock 16" mini-van tires for a softer ride. Man - on many lifted concrete sections of busted up old interstate while traveling across some states with low profile tires feels like you need another complete suspension rebuild.

I've seen where there are 928 owners that's happy with their tire/rim combination but I've just not found the right compromise that suits me yet. What I may need is a "Gas Monkey Garage" air bag suspension upgrade.......

Michael

[Pete R]

Ha, ya gotta do what works. I just thought it was an illusion from the pic.