Fiat X1/9 1500 engine tuning question.

[X1/9]

I have a 138 B3.000 engine in my X1/9 is this a good SOCH tuning engine or should i get something else?

I did a dyno run with it and it has 85BHP at 5600rpm and 113Nm at 3700rpm this seems like standard measuring, but it is fitted with two double 40mm IDF and has a 4-1 manifold with 2in exhaust system.

Not a very effective tuning :-)

I am building a full race engine and I am looking for a complete engine managing system like the Weber Redline Fuel Management with ignition management.
Anyone tried that or have any suggestions of other systems that is better or more advanced?

I am trying to get 200+BHP or closer to 300 would be nice, anyone done that?

[Guy Croft]

200-300 bhp - No way!

Even if you get 100bhp per liter on an engine with 2 valves per cylinder (150 on 1500cc) you are doing well. A bit more (160 or so) is possible but not easy.

As this is GC Q&A in a race engine forum, where I call on my years of exp of prepping engines and cars (strong enough for the engine) and take things very seriously indeed - in terms of what I write and suggest - I will simply say at this stage that unless you have a very big budget available you would be better setting your sights lower at 140bhp or so.

GC

[Julian]

A little bit of history on that particular engine - back in the day when it was being developed in-house for competition use the 128/138 series engines were regarded as a very good unit but the peak figures were roughly 170bhp for the 1300 and 190bhp for the 1500. You can still buy similarly prepared engines but the costs are substantial, even by motorsport standards.

The possibilities of achieving more than this are slim even with the latest in technology. The only way the likes of Abarth and Dallara could push the output further was to opt for custom 16v heads. Even then the final gains were nothing huge on paper but a much more driveable engine was apparent.

One of the limiting factors of the technology used at the time was mechanical fuel injection, a modern mappable electronic injection system should be far better for driveability but is unlikely to deliver more power as the limiting factor is flow of gas through the head, not how much fuel you can squeeze in.

[Guy Croft]

Julian, hi

could you declare the origin of those power figures, just for the record please? I'm sure, knowing you, it's substantiable.

Thanks,

GC

[Julian]

I certainly shall - I've been referring to them as common knowledge for so many years that I will actually have to go back and find the research again - but I promise I will do it! (do you know how many times I've wiped my computer hard drives since then?)

The "still available" engines come from east european sources and I seem to remember one of them is Jupiter Racing. There is another but I will have to find it again.

edit: Jupiter Racing do not quote power figures so I need to keep looking for the other source I mentioned. They do quote a potential 110bhp/litre for their full race cylinder heads - that equates to just under 165bhp on stock capacity. The race 1500 engines were typically stroked out to nearer 1600cc... I know this isn't substantiating the claim, I was just doing the relatively easy bit now.

edit 2: Filipinetti's cars used the 1300 engine and quoted all sorts of figures depending on which particular implementation they were referring to. The later engines used the same 16v head adopted by Dallara (after Filipinetti's death) so it is hard to distinguish whether a given engine used an 8v head or one of their inhouse 16v heads. The lowest figure quoted is 160ps from the 1300 (about 157bhp), rising to 220ps (215bhp) which is most definitely on the 16v head. Dallara moved on to a larger capacity engine and achieved The early system used lucas injection and the few pictures I've seen show an 8v head, the later engines used kugelfischer injection and I've seen both 8v and 16v versions. For those that wish to know a bit more Filipinetti founded his team back in 1962 and became a world class privateer. His last venture was the X1/9 but the project was short lived due to Filipinetti's death. Dallara had worked with Filipinetti on the 16v head design and had some significant stake in the X1/9 development. When Filipinetti died Dallara took the bulk of the work with him to his own company (now rather well known) and useed the work as a springboard for his own silhouette project. In the UK this is most recognised by Radbourne Racing's efforts. The irony in all of this is of course the fact that the sohc engine was based on Lampredi's dohc design that was "shrunk" to provide Fiat with an advanced OHC design for their road cars...

I believe Phil Ward provided some quoted figures in one of his old articles but as I keep saying I will have to do some digging to find the materiel I refer to.

The caveat on all this is of course that these are quoted figures from various sources and as such there is an element of subterfuge as they rarely quoted actual figures at any time.

more to come....

edit 3: Looks like my archived notes and favourite web links are history so it is going to take a while to find the information I used as the basis of the above claims. I will find it again though!

[Guy Croft]

Thanks!

Bjorn - this might be worth a read:

http://guy-croft.com/viewtopic.php?t=816

That SOHC head was originally from & destined for a 1300 Uno, ended up on a 1600 Tipo block, don't know what it would have given on a 1300 in all conscience. A lot less probably, about 140bhp. On a 1500 say 160 or so. Big valves not huge ports.

GC

[X1/9]

Thanks Guy and Julian

I am probably optimistic regarding the 1500 but I don¢ž¢t like the idea to fit a TC engine in my X1/9 because more weight at the back is not something I need.
The TC fitting kits seems to not exist anymore and Guy you warned me about the hassle to do the fitting job from scratch in a e-mail a while ago.

Are there another SOHC Fiat engine that is a better tuning base, or is it only the TC engines that passes 200bhp?

I have been building TC engines for my 131 Racing 15 years ago, but now I am mostly assisting one of Norway¢ž¢s best engine builder's building race V8 and V10 engines for speedboats, dragsters and track racing cars.

So I have the equipment and a very good engine builder to assist me if needed, but he does not have any experience on the beautiful Fiat engines yet that¢ž¢s why I appreciate and need your advice.

This is not going to be a cheap project I know, I am probably going to use 3-4000.00 GBP only on the managing system and I have dyno's for testing and fin tuning.

My goal is to get a little Fiat that outruns the Vipers and Corvette's, I'll probably take them in the cornering but i need some power on the straigts :-)

I'm an optimist ok.....

[Guy Croft]

I'm an optimist too, but I am a realist.

You will NOT be able to get more than 140-145 or 150 absolute tops or so from the 1300 8v whatever you do to it. And your best hope is a GC prepped big valve head with big lift cams with big lift integral, FI, race rods and pistons. And the more bhp you chase the less driveability you will get. F1 engines, sure they give, dunno, 900bhp at 20,000 rpm but they don't have any more torque than any other well sorted 2.5/2 liter engine and it's all way up the rpm band.

Yes, the one to give 200bhp if you know how (I am one of the few who really has done it with the 8V n/a unit) is the 2 liter TC or a late 16v head conversion, easily tops 200 if you can do the conversion/installation required. As for beating much bigger bigger engines, sorry to put it this way, forget the 'giant killer' stuff, it can't be done. I should know, I have tried it, behind the wheel too. You might give them a race up to about 80mph but then they will leave_you_for_dead.

Sorry to be rather 'pointed' about this. I don't want GC Q&A drifting into impractical and unattainable big_bhp_numbers madness like every other website on the planet.

I suggest you start stripping out your motor and make some key decisions.

GC

[X1/9]

Thanks Guy

I have spear 1500 engine ready for some tune up in my garage, and I¢ž¢ll try to go as close as possible to 200 bhp then :)

[Scorpion77]

Well lets see....Wasn't BMW able to build turbocharged F1 engines of 1.5 liters in the early 80's that put out 1000 bhp? Late 70's, early 80's Lancia Monte Carlo Group 5 car. 2 liter, 4 cylinder turbo made 400 bhp. Nothing is impossible. But like Guy said, you better have a pretty thick checkbook.

[Guy Croft]

Bjorn, listen.

Don't set your sights so high, 200bhp from an 8V 1500. You won't get anywhere near that, unless perhaps you turbo it or supercharge, in which case it's easy to get there, albeit very expensive (if you want it to last more than 5 minutes anyway).

Read GC V/W - don't just look at it and say, oh yes.. This stuff is relevant. I should know - and I do. V/W is published freely so that guys can learn. I always considered it to be important and I've spent years coaching newcomers and experts alike.


GC

[andy97]

Sorry if I am being dim but what is GC V/W & where do i find it please?

[benlilly]

Go to the forum index index.php
V/T (virtual workshop) is the top 8 sections of the page. It is the section of the website where Guy posts tips, 'how to' guides and results.

[johnv]

just to back this up a little .. I have a GC engine in my X1/9, it's maybe 130bhp? but I have had to replace what seems like every mechanical component around it .. all the original stuff failed one piece after the other .. it does 'tear the car apart' .. great when you get it all 'integrated' though - 3 years later and I'm almost there!

[Julian]

I call it the mini brake cylinder syndrome.

You take a (classic) mini to the MOT station and they fail it on one wheel cylinder, so you replace it, take it back for a new MOT and they fail it on another one, so you do the same again, and again until all 6 (or 8) cylinders have been replaced.

The problem is that all of the cylinders are weak but only one will leak at a time (normally), that being the weakest one. Fix that and you just move the problem... The weak point moves as you fix the bit that is "broken" until you've done the entire lot.

The only saving grace with an X1/9 is just how incredibly strong the car is to start with. I've spent thousands (literally) on this subject and the one thing I've never had a problem with is the chassis itself (except for keeping up with the rust).