General Fiat X1/9, 4-1 high performance exhaust manfiodl WANTED

[SpiritX]

Hi guys, I am new to this forum but have always been visiting as a guest.
I was upgrading my X1/9 during last year and I left with few more things to do.
I was looking everywhere for a 4-1 sports exhaust manifold and couldnt find it. Mad Matt in US had some, but they were sold very fast.
If you are looking to sell one or have any ideas where I can get it => please tell me (I am currently in UK, but the car is in another country)

Here is my X1/9:

 

[jimbro1000]

The only option off the shelf that you are likely to find is the CSC system, however it is geared towards a mid-range torque boost (brilliant for driving on winding roads) rather than peak performance.

If it is top end performance you want then you are basically on your own but for a tuned engine it isn't such a bad place to be as the off the shelf stuff is likely to be inappropriate anyway.

 

[SpiritX]

Thanks for reply jimbro1000.

Thats what I was looking for - mid-range torgue boost. I have a good peak performance from dual 40 DCNF's and street cam adjusted to give max power on about 7000 rpm. So I am really lacking torgue on low rpm.

I was also thinking to get air horns for twin DCNFs cuz they are actually made to work from about 5000 rpm, and I need something lower cuz I have a street car.

As for CSC system, I have found one on eurosport-uk.net
And I reckon the same one is on ebay, but the manifold comes with the silencer which I have allready made.
And it is worth 400 punds all together - pretty much...

Do you know any other places to look for CSC system?

Thanks again.

 

[jimbro1000]

There are two CSC systems, the one you want comes as 3 seperate parts, manifold, pipe and silencer. The pipe is basically just a U-bend that runs the exhaust from the headers, around the wheelarch and back along the cavity where the exhaust normally sits.

You used to be able to buy the manifold seperately but I've no idea if that is the case still. No idea where to get them from these days either but eurosport is normally pretty good.

 

[SpiritX]

Thanks a lot, I will go into contact with eurosport then.

In my previous reply I wrote about Air Horns for twin DCNFs. Did you had any experience with them jimbro1000? Will they help getting rpm-range lower?

 

[jimbro1000]

The problem with the DCNFs, and webers in general is that they are optimised for a fixed air-flow rate. Too small an engine with too big a venturi size and you only get performance at the top end (if at all).

You can try rejetting the DCNFs to get the mixture corrected for lower rpms but the odds are you just don't have enough gas flow to get them working right.

Fitting trumpets (air horns) normally only works at the top end where they act to smooth the air flow into the throat of the carburettor. Different length and diameter trumpets work at different engine speeds.

The CSC manifold should help a bit as it reduces the back pressure a bit so the gas flow should be marginally better but the only thing that is really going to help is to sort the cylinder head. Slightly enlarged inlet valves with some work on the ports and combustion chambers would do wonders to improve the flow at all revs. An increase in bore size would also help, as would a new look at the cam profile. You might find the easiest option though is to find some slightly smaller DCNFs...

 

[SpiritX]

Ok, I see.

I have been jetting them and testing about a month without any supply of jets (I had to them myself). I had lots of trouble with bad idle, with high CO2 and fuel consumption. Finally I think I made the best I can.
I have a Yugo cylinder head with slightly larger valves and work on chambers with a Delta camshaft.

Car runs very well if going to 7000 rpm on each gear, but If lower than 6000 - significant difference. From our discussion I think that it is a matter of exhaust manifold here, cuz its realy old nad not made to work with tuned engine.

I have one more question if you dont mind
I was thinking about getting a lightweight flywheel. Does it have any effect on idle rpm? Cuz I know that lightened flywheels usualy make idle bad.

 

[jimbro1000]

The flywheel won't make much difference if you already have poor low revs running, it will just exaggerate the variations in revs.

Why the Yugo head? I know they use them on the Fed. spec engines but that is only because they have such badly crippled combustion chambers for the emissions controls and the Yugo head is a good upgrade. The european engines came with a better head as standard. Then again it depends on how good the cylinder head work is, once you start modifying it doesn't make much odds which one you start from.

The enlarged valves are an improvement but I'm going to guess that you've increase the exhaust valve size which likely isn't having as much of a benefit as you'd like while the inlet valves need more to get the benefits. The flow problems with these engines has never really been on the exhaust side of the head, it is getting the gas into the cylinders in the first place that they struggle with. That said if you do have a restrictive exhaust it is worth getting rid of.

 

[SpiritX]

I got my cylinder had from Mad Matt in US(midwest-x19.com) as most of my parts.

Thats how they did it:

1500 cylinder heads have larger ports and exhaust valves than a 1300 head, and have a more efficiently-shaped combustion chamber. When milled -.075, it increases compression nearly to the level that a Yugo head can provide. Throw in a hot cam, and a good valve job, and this unit will really wake up the performance of your car.

We start with a very good condition 1500 10-bolt carbureted head, with 12mm head bolt holes. All threads / stud holes are intact, and clean coolant passages absent of corrosion or enlarged openings. All spark plug and coolant sensor holes have clean threads, and we replace any valve guide whose measurements are out of spec. We mill the head .075 to completely remove the combustion chamber "dish". Note: Milling the head by this amount WILL affect cam timing. While the engine will run and operate correctly with stock gear, an adjustable cam timing gear is recommended to optimize performance through proper cam and crank timing. A 1300-style cam belt tensioner bracket and bearing will be required to correctly tension the timing belt.

We tap and plug all emissions ports, and tap the intake manifold coolant holes with a 5/16 x 20 thread so that they can be easily blocked if desired. Intake runners and valve throats are fully ported and polished. New (not used) valves and provide a trick three-angle valve cut on the seats which has been flowbench proven to increase flow by nearly 40%! New Isky competition valve springs with stock retainers are used, which are guaranteed to put up with a high RPM beating up to 9K RPM without danger of valve float.

 

[jimbro1000]

So do you have a vernier pulley fitted?

That is a fairly hefty bit of headwork without actually doing an awful lot to the ports. I'm not disputing that everything listed is beneficialy but basically it is a heavily skimmed stock head with carefully worked valve seats and decent valve springs.

No mention of valve sizes, combustion chamber cc's, leak down tests, flow rates, etc.

I also have to question the choice of camshaft. I'm not aware of any significant difference between the euro-spec 1500 cam profile and the Delta 1500 cam profile. Given that they are reasonably close to each other in profile (if I am right) then the entirety of your peaky performance is down to the DCNFs. You have improved gas flow (if the valve seats are doing their job) and increased compression ratio from the skimmed head (not as much as you think when you compare a european cylinder head with a federal spec cylinder head - it makes a big difference to a fed spec engine).

An exhaust system that gives more mid-range punch *is* going to help, you are on the right tracks there but I'm not sure it will give you as much as you need.

I suggest you get your exhaust fitted and take the car to an old-school rolling road and get the car rejetted there. Rejetting from home without a rolling road is a lottery, it can be done but it takes a lot of time...

 

[SpiritX]

Um... Actually I havent been doing any work myself. The very big problem that I have is living in a dumb country that doesnt have decent guys who can make good job especcialy with this car.
As from their words, they fited the cylinder head and cam and adjusted timing without the pulley. Saying that the pulley wont make much difference.

As for cylinder head I had to believe that its a good performance piece as I had no knowledge about heads. The supplier - Mad Matt seemed to me as a good mechanic, being an X1/9 US racer.


Here are the specs of my cam, its alternative to FAZA 40-80 Daytona:
Grind ID: "Delta A-15"
112 degree lobe center
40-80 / 80 -40 (seat-to-seat)
240 (int. / exh.) degrees duration @ .050 lift
10.1mm (.398") maximum lift

Again, my main problem first of all is not being a mechanic.
Guys out there in my country dont have any experience in working with such cars, they saw an X1/9 first time in their lives, so its hard for them to sugest anything(only from main mechanical perspective based on exprience from other cars). And the last one - part supply only from US nd UK which takes 2-3 weeks. Think about jets for carbs, 25$ each emulsion tube, and no idea which one will work...

So basically thats why I am here, looking for advices.

 

[jimbro1000]

So what country are you in? Or rather what country is the car in?

Matt was quite right about the vernier pulley, the cam timing won't be far off but the teeth are quite large and without a vernier that is the "resolution" of your adjustments. You need the kind of infinite resolution adjustment you get with a vernier to get timing spot on (and it really does make a difference). I've had enough instances of timing belts skipping in racing to know how much just 1 tooth out can make to your lap times. You don't even want to think about how bad 2 teeth out is.

The cam you describe is slightly more aggressive than the european spec camshaft and a lot more aggressive than the federal specification profile.

The matter of the jetting really shouldn't require that kind of delay - weber carburettors are fairly widely spread but admittedly not many cars use such technology these days since everything is on fuel injection now. Even in the uk you need to find a specialist rolling road to get the service you need. You shouldn't need to mess around with the emulsion tube much, just the jets but that doesn't help much if you don't have a local supply.

 

[SpiritX]

Currently I am in UK for couple of years. But the car is in a post-soviet country, you never heard of - Moldova. It a small country in between Ukraine and Romania, underneath Russia. Its a russian and romanian-speaking country with extremely bad economy. Nearly nothing good about it

To sum up your sugestions, I should:

1. Fit a vernier pulley to make a proper timing
2. Fit a new 4-1 exhaust manifold
3. Afterall check and rejet DCNF's

 

[jimbro1000]

Re: Fiat X1/9, 4-1 high performance exhaust manifold WANTED

I know it isn't quite the same corner of the world but there are so pretty good tuners who specialise in this sort of thing in Yugoslavia and Poland (that really shouldn't come as too much of a surprise). The best of these that I know of is Jupiter Racing (http://jupiterfiatpower.tripod.com/index.html) in Macedonia. They have a pretty good idea of what they are at.

If all else fails I suggest you talk to my sponsor, Wolf Direct Racing (http://www.wolfdirectracing.com) in the UK while you are still local-ish. They aren't specialising in Fiats any more but they still really know their stuff and are responsible for a number of successful, high performance racing engines in Fiats over the last few years.

 

[SpiritX]

Thanks a lot jimbro, I have already found that Jupiter Racing have pulleys and flywheels!

Many many thanks again.