Rolling road dyno, worth doing?

1-cooling is still at the front so the dyno people will put the fan there
2-anything can be changed but it’s old school. Different profile cams etc but it’s not as tho you can hook up a laptop and change the curve
3-My 308 runs happily on all the 97+ octane from the usual suspects here in the uk
4- No need to pump Just turn the key. Move off straight away. I keep below 3k as it warms up which takes about 15 miles-like any car. The coolant temp reaches its usual temperature before that but the oil temp takes longer. Redline is mentioned in the handbook but it pulls as well in the next gear after you’ve covered the torque band , so I’ve never bothered. Never found the need for an Italian tune up -just keep it set up the way the original engineers did. I’m not stuck with city traffic but it’s quite happy if stuck in a jam no need to anything different.
I’d just drive it get used to how it sounds feels smells etc. it’s a 40 yo car in all its old fashioned glory.

 

Without baseline numbers produced before your recent service and addition of the new exhaust, the dyno numbers you generate now will have no point of reference. That said, the numbers you pull now will become your baseline...so still useful. As for your other questions, agree with everything Michael said above, but would emphasize using oil temp - not water temp - to indicate the proper warm-up period.
A last comment about warm-up: if it's driving season and the car's been sitting for a while ("a while" for me = 2+ weeks), I pull the coil wires from the coils and turn the engine over until I get oil pressure on the gauge. It's easier on the bearing surfaces to pre-oil without the stress/pressure of combustion. If we're coming into driving season and the car's not been able to be driven at all during the Winter, I'll also pull the spark plugs before cranking over the engine, which not only eliminates the stress/pressure of combustion, but also eliminates the stress/pressure of compression.
Would also add that if the 328's oil cooler is plumbed to the left-hand side air intake as on the 308, I'd aim an external fan at that intake while on the dyno. It also isn't going to hurt anything to open the engine cover and point a big fan at the engine too.
Enjoy and be sure to let us know how the old girl does on the dyno.
- Dave

 

This is what I do when I dyno my F355. Mounted a big fan on a wall support aimed directly at the side intake and engine. (and another fan on the passenger side)

 

I wouldn't do it at all.

It's a 40 yr old car, if the plugs are all the right colour & its running cleanly on all 8 then why wring it's neck & risk breaking something for what will inevitably be disappointing information!?

Aside from making sure it's set up as it should be (CO levels etc), there is nothing you can adjust or tweak to make it run better.

If you really want to check how healthy / worn it is then I'd go the compression / leak down test first.

 

A healthy 328 will make between 210-220hp at the wheels on a dynojet. I cannot speak to other types of dynos but the gold standard from which all comparisons can be drawn from is indeed a dynojet. The Maha dyno is also good but they are rare

 

ASSUMING the engine is in good shape, I wouldn't worry at all about winding it out close to redline. I do that EVERY time I drive my '89 328 through at least a couple of gears depending on the road/traffic, usually multiple times!! The 328 has a rev limiter so it will prevent any problem if you miss a shift. It works well, I know this from several personal experiences!!

Never had mine dynoed even though I did a LOT of dyno work as a competition/high performance engine builder. But based on magazine road tests at the time with 1/4 mile trap speeds, I'd expect to see something like what John posted in message #7 - 220 or thereabouts. The exhaust mod MAY add a couple of HP... OR subtract some - I've seen both happen. In one case a "straight through" muffler (literally roll a golf ball through the muffler) reduced max HP by 7 HP over a stock muffler!

In any case t will be interesting to see the dyno curve; please post it when you get it done!!

 

@FastandSlow it sounds like you want to dyno your car and you're mostly looking for affirmation.....so heck yes you should dyno it!

mostly its going to let you really hear the new exhaust and its kind of a cool experience. I believe it is possible to adjust the mixture on CIS which could add a touch more hp but I've never done it, other may know which screw to turn..

 

Just drive the damn thing. No point in discovering it makes less hp then the average mini-van. What are you going to do with the data?

 

LOL! Good point!

 

Dyno it if for no other reason than to have fun. I have dynoed my 78 308. I use a 62oldfart butt dyno. My results were 605.2 HP and 702.8 TQ. Your results may vary
I have hade a couple of my cars on a dyno. One was what I expected the other was a disappointment. I have thought about doing the 308 also just for the fun of it.

 

A simple compression test will tell you plenty about the health of the motor.
My JCW Coupe was dynode at the wheels with 230. I Have not dynode my Exige I know it should be a lot more. But I don't compare the 308 to a modern car. A 1978 Trans Am I think was rated at 220HP, I am not sure if that is at the wheels, with a 6.6 liter. The 78 308 was 240 I believe. That shows how great these cars are.
I think an old school build on a 308 would be a blast.

 

Your car has a CIS system and CIS is pretty sensitive to reversion so you really can't do much of anything with the cams.

Porting can gain 10-20% more flow without a lot of effort The exhaust is over ported from the factory so most effort goes into the intake side. You can go to 31-31.25mm on the stock seats....348 intakes are 30.5 mm iirc so that is an option too, stock is 29mm again iirc.

The intake become the main flow restriction almost as soon as you touch the ports. You can just keep adding flow to the heads and it will pull more through the intake but its kind of a diminishing return game where you keep opening up the port which raises the peak torque rpm and hurts low rpm torque to see a fraction of the new head flow once the intake is installed....that is kind or why I said 10-20% because that is kind of where I've run into a wall with the intake and CIS system.

You can over come this a bit with a 3.4 or 3.6l conversion....more displacement means more torque everywhere so its more tolerant of over porting the heads to try to pull more air through the intake and CIS setup.

Or you ditch the CIS and do EFI, preferably with ITBs, and then you add cams too and 300rwhp is within reach......or you could leave it be and "drive the damn thing"

 

Many years ago I thought about "more power" for my 328 and decided that the way I would go was forced induction. At the time there was a company - can't remember the name - that offered a kit for around 6-7k USD. I had decided to buy one but then the IRS advised me that they needed my "supercharger" money more than I did so they got the money; the kit maker didn't. I subsequently lost interest in performance increases.

A good running 328 is not embarrassingly slow - mine will bark the tires into second gear and will actually out accelerate our turbo Hyundai Santa Fe but gets left for dead by my wife's S580. One "free" item that will boost low end performance slightly is to change the Microplex setting from the USA timing curves to the Euro timing curves. It's quite easy but since I did it over 10 years ago, I can't remember whether it involved MOVING a wire on the Microplex from one terminal to another or adding a wire. I seem to recall it was adding a ground to a terminal BUT DO NOT quote me on that. I posted all about it on this site so it SHOULD be searchable if you are interested. The Euro curve will fail a USA emissions test if that's a consideration though a 5 minute wire change would put it back to stock.

The low end increase IS noticeable and I posted how I used a water puddle in the marina parking lot to "scientifically" test the difference with a switch in the cockpit that could instantly change from US to Euro curve.

 

A 50% bump is possible...30-40% is easier of course

The big thing is the CIS needs to go, once that happens you have a lot of freedom. With a good ITB setup the total flow increase will match the head flow increases and hp increase will match the flow increase. 30% is not hard, 50% is possible if you up size the seats and go to 32mm intakes and decent cams....something in the 240-250 deg @ 0,05" lift range. The issue you run into though is rpm also increases about the same %.....so you end up with a 9k+ hp peak and that means better pistons and rods and valve springs. Adding a 360 crank and possibly 85mm bore will drop the peak hp rpm about proportional to the displacement increase. And you'll need a better clutch.

These engines act like any other engines....it just cost a lot more to make the upgrades

 

You don't do any of that stuff on a 3x8 without spending disproportionatly huge sums of money. The power in any engine is in the heads & the way it breathes & t0 do as Mark suggests above is going to run to 5 figures I would think.

Its a personal view but I think if a 3x8 doesn't have enough power for you then you probably bought the wrong car bearing in mind you could probably have picked up a 360 & certainly a California for the same money.

Its not really what these things are about any more.

Then again, there are brilliant nutcases aroundlike Mark & the world is better for them! (See the V12 into a 308 thread!)

 

Yeah, that is the issue.

Head work - $5k-$10k
Custom ITB setup - $3k-$10k
Cams - $2k-$4k
Pistons - $2k
Rods - $3k
ECU- $2k

So best case you'd have $20k in parts but if you're building it as a 3.6 I would think $30k-40k in parts. Its hard to describe in words just how wonderful a 400hp+hp 308/328 is to drive but you can put a price on the experience.

 

I would go back to my original decision if I was looking for more power. Forced induction is by far the most cost effective and efficient method to gain HP AND you can easily tune (adjust) the max power to suit the rest of the drivetrain. Typically you can increase engine power by 30% in ANY car without worries about the clutch/transmission/axles. I've been told on this site by folks who know these cars well that a 3x8 can handle considerably more than that. Frankly, I don't see any reason to mess with these Ferrari engine internals to gain power simply because of the cost involved. If it was a US V8, that would be a different story...but it's not.

Another advantage of forced induction is that if resale is eventually a consideration, the system can be removed/the car returned to totally stock.

 

Boost is for sure the cheapest way to add hp and that was my 1st and 2nd choice as I did it twice. As you say the stock engine is quite robust and will handle 12-15 psi. Intake valves will start to flow at around 18 psi so that is the hard stop for a stock engine but head gasket problem may strike sooner.....the QV/328 type gaskets do NOT tolerate detonation, the hard flame ring fails and makes a mess in the bore.

I used a roots and then a screw compressor to help the bottom end not just the top so the closest thing to a bigger engine. It was fast for sure. the 1st setup made 301rwhp, the 2nd made about 425rwhp, this is a QV. It also change the feel of the car....the sound was very different with a lot of blower whine and with the 2nd setup in particular it really felt more like a big block vette than a 308....it would sort of shake and GO!. I liked it but I didn't love it because it just didn't feel like a 308 any more.

Engine 3 is naturally aspirated on purpose and I'm much happier (when it actually runs ). It feels and sounds like a 308 again, just WAY faster. Wonderful to drive, other than the expense to built it. My per cylinder displacement is also exactly the same as a 3.6 V8, but 78mm stroke and 86mm bore instead of 79/85 so I would expect a 3.6 conversion to feel similar but looking for a bit more rpm.

I guess where I'm going is I've kind of learned there is more to the picture than the hp. HP is all you need to know to calculate acceleration rate, but the driving experience is a lot more than acceleration which is why most 308/328 owners are perfectly happy with stock hp.

 

This is the best course of action. From your first post it would seem that you haven't driven this car very much yet, if at all. A well-sorted 328 has got ample torque and power for its weight, it's a lovely thing to drive. The perfect instrument for exploring twisty back roads.

 

I tend to agree. I put my 308GT4 on the rolling road at DK Engineering here in UK 3 days after I bought the car. Scared the **** out of me the way it had to be revved. They did everything so no need to even think about how to do it . Good thing was that it recorded 237bhp which was pretty good for a then 36 year old engine, albeit by then fitted with high compression pistons.

But never again!