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Forum nameTurbo/Nitrous Tech
Topic subjectHigh Compression Ratio + Turbo...
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=44880
44880, High Compression Ratio + Turbo...
Posted by CopperEclipse96, Mar-16-03 05:58 PM
How much more do you have to tune it? What would I additionaly need, that I wouldn't for a regular turbo set-up. I do have acces to a dyno, and a guy that is one of the top porshce tuners around. He even tunes some le mans cars, so he knows what he is doing. Buy anyways, what else would I need? I want some more info, because I would love to do a 2.4L swap, w/ stock or higher compression, and a nice turbo. thanks.
44883, RE: High Compression Ratio + Turbo...
Posted by neovb, Mar-16-03 07:09 PM
To run really high compression, youd need to concentrate on precise fuel and boost control. Id estimate you'd at the least need an SAFC, a REALLY accurate a/f gauge (probably the digital voltage ones), and an accurate EGT. You'd probably need larger injectors, maybe a fuel rail, and definately a fuel pump. If running superhigh compresion you might have to even get a more advanced tuning computer to make sure you dont blow yourself up. Id also probably think youd need an extremely accurate boost controller, an electronic one probably, as well as an accurate boost gauge. A LOT of tuning would be in order to run high compression with boost.

I personally wouldnt go any higher than 10:1 compression with turbo. At that rate, you still need to maintain precise fuel control but you still have some little leeway. If you choose to go into the 11 or 12:1 range, youre going to need some serious tuning to make sure you dont blow something up. Id probably recommend sticking with the stock compression (with built internals) and boosting on that. Its safe, reliable, and isnt super risky. But then if you have someone who knows what they are doing and are going to help you out, it would be a lot easier then trying to do it yourself.
44886, RE: High Compression Ratio + Turbo...
Posted by mcgyvr, Mar-17-03 03:09 AM
You need an ignition amp with timing retard/ and Safc and some wideband dyno time.

I wouldnt go over 10.5 compression unless your just building a pure race car then 12 or 14 compression. But this will def require a standalone and a super tuner.

The digital air/fuel guage wont help, your still running it off of the stock o2 sensor which is far from accurate. You can either spend alot of time on the dyno with wideband or buy your own wideband o2 guage with sensor.
44913, RE: High Compression Ratio + Turbo...
Posted by CopperEclipse96, Mar-17-03 09:09 AM
Is the stock compressin ratio 10:1? I wouldn't plan on going much higher than stock if at all. I'm just wondering what else I would need. What is "wideband dyno time"? You guys lost me there.
44927, RE: High Compression Ratio + Turbo...
Posted by DR1665, Mar-17-03 11:41 AM
Stock comp is 9.6:1 I believe. Good luck.
It might be a good idea to grab some of the higher-end gauges and install them now so you can see how things run when normal. You know, to get a feel for reading and tuning things yourself. Dyno time's always expensive. Even if you get it for free, it costs your buddy who could obviously be making some money at the time. Keep us posted. High comp + boost = tasty! :9
44937, RE: High Compression Ratio + Turbo...
Posted by XtremeRS, Mar-17-03 03:11 PM
I'm sure it can be done, but like said in the other posts, tuning will take some dedication and time, not to mention the proper hardware. I will agree with the other reply, a good stand alone (eg. Haltech) will be almost needed to retune the whole fuel and ignition curve so you dont blow it up to detonation. I'd REALLY like to see the power output of high compresson and turbo, esp 12:1 ratio :)
44939, RE: High Compression Ratio + Turbo...
Posted by DarkOne, Mar-17-03 03:26 PM
The only problem is that people want to do this on 93 octane, and its just too damn hard to tune a steetcar for 11+:1 compression and boost. That's just too much for pumpgas. 119, sure, 12:1 compression and 15psi is possibly do-able, but then its not really a street car, is it?