Thanks everyone for contributing to the thread. A wealth of information!
Its hard to criticize a proven successful winning build, like Graversens, and he clearly did a great job with his piping, but I would think he's leaving significant HP on the table with all that piping. No doubt intercooling (of some sort) is necessary for high boost but, I feel that's where gastrous cooling would lend a big hand. In C4 Vette Turbo/SC builds, we learned Turbo/SCs pushed well, but pulled poor. We found short intake side, Airfilters almost direct to SC was more valuable than cold air feed or tunneled scooped air. On the output side, they tried dual intercoolers w/ fans in front wheel wells under headlights, and found any gains were lost due to the restrictions of excessive piping necessary to interconnect. Problem solved with Gastrous Intercooling, to tune maximum efficiency and consistency of boosting engine. Although much more air flow is needed to support a higher displacement 8 cyl 383 stroked chevy engine, than a 1.4L small bore, so maybe not an equivelent comparison. (not that this thread is about benefits of gastrous cooling).
Bjorn wrote "but 400hp is probably as far you can go without adding water/meth."
Thats pretty amazing, if that much boost can be achieved with just air-to-air Intercooling. Actually pretty amazing that that much boost in any configuration is possible with the FIAT X compatible engines. But I still feel benefits of gastrous cooling can be realized starting at much lower boost levels. And the X19 being mid engine, the rear trunk, inside rear wheel fender, has plenty of space to place a sizable water tank. Gastrous would go a long way towards keeping combustion chamber temps down. My theory is that it could help reduce frequency of head failures. As Steve points out, the head may fail due to alloy becoming weak at high temp, apposed to just compression forces.
SteveC wrote "All Uno T and Punto GT cylinder heads tend to have issues around the areas of 2/3 cylinders, where the exhaust passages are "siamesed" "
Any way to solve that? Just expect it, or is their a better head alternative? Where you referencing both MKII and MKI turbo heads?
Im hearing from this thread and understanding why, for reliability and compromise of all things considered, I'd be much better served starting out a High HP Turbo build with the stronger MK1 Turbo closed block, if I can find one.
However, I'd point out, if I cant find a MK1 Turbo block, there could be advantages of going a different route with lower boost.
Its easier to manage and tune increased displacement (via bore/stroke) because the gain is consistent across the full RPM range.
And small Turbo is physically easier to fit into engine bay than a bigger footprint Turbo.
Could be less expensive, because the alternative high boost application surely will require conversion to Fuel Inj and a more sophisticated Electronic Fuel management system, that potentially could be as or more costly than engine parts and machine work.
If I reference my C4 Vette builds, (I have 4 uniquely different prepaired C4s, 2 race, 2 street). My Stroked 383 Street C4 has about 500HP and a broader high torque range. My near stock 350 modestly centrificle SuperCharged (about 10 PSI) C4 has about 450 HP. (I had to limit boost because engine internals not upgraded to handle more yet). The Non-Supercharged engines is faster. Part of this is because both cars peak out at about 6000 RPMs. The stroke on the 383 is a RPM bottle neck. On the 350, The heads and intakes are flow and RPM bottlenecks. Im certain if I did a performance head upgrade (195 to 210 range), maybe better beehive springs, some stronger pistons, I could safely get my RPMs up much higher, and the SC's Vette would then likely blow away the 383. What I dont know is how well these lessons would apply to a FIAT small bore.
What I am seeing is the only FIAT X1/9s making it over 200HP are Turbo or SC'd.
One of the things that I often get confused on and forget is..... I get in my head Turbo is mostly working only at High RPM.
Thats not really true. The pulley always has a consistent ratio. When Dyno plotted, usually the pre-boosted Torque curve when boosted, the new curve just replicates the old one at a higher level up by near the same amount across the full RPM range. So modifying the engine internally can be beneficial, if there is a reason and desire to modify the torque curve, Sure at High RPM under SC/Turbo, the PSI grows exponentially higher and quicker, because of the RPM multiplication factor, but that's not necessarily seen at the lower midrange drivable range in torque values. obviously many variable due to parasidic losses and temps and such.
. Impressing result with such old stuff. I wouldn't dare to do that with an old mechanical injection (even if Kugelfischer is cult) and legacy ECU. The injectors are crazy big so I guess he is running on E85. Very low compression so I assume even more boost is possible especially if runnig on 85.
