I think jeff was running 12-15 psi. then he lowered the compression and is in the 20s. I myself would stay below 15 untill I was absolutely sure the tuning was spot on. the good thing you have going for you is 9.3:1 CR instead of the zetec's 9.6:1.
numbers I have see for spi's like that are in the over 200 whp range.
yeah man, i was just thinking about it, i dont think im gonna turbo it. although me and my buddy know this guy that makes turbo manifolds and he prolly could hook me up with one. my friend convinced me to just save my pennies and do the full on engine and tranny swap. he also convinced me not to buy a repairable cuz in the long run it'd cost more. (taxes, registration, insurance, etc...) so i'm doin a full on engine + tranny swap. manual trans conversion too i think. then im gonna turbo it. so for the zetec, how much boost on stock internals do ya think i could do???
oh yeah, why do turbo's need lower compression? is it so the engine wont explode or sometin??
Last edited on Wed Feb 9th, 2005 05:24 pm by docinsano
Tom's kit has produced sustainable boost to 15psi on stock internals. most people I think stay at or around 10 though. Alot of it has to do with the tuning. knock and heat are your enemys.
lower compression is good for FI. without writing you a whole book on it we will jsut say that it has most to do with heat. less heat = less deto so timing can be advanced a little further. There is a good explanation in a book I am currently borrowing, I will type it out for you when I get home tonight.
With the stock 9.3 compression, 93 Octane gas stock N/A timing (Escort ECU with out the knock sensor) I could run 8psi, anything higher and it was welcome to deto city.
But it's all in the tuning, I had stock ignition timing, with a chip I could have pull some timing and run more boost.
But for me it was cheaper to run low compression, now I run any where from 15-17psi on the street and 20psi on the dyno.
But honestly, if your gonna go turbo there's not much advantage to swapping to a Zetec. Both the stock internals of the Zetec and SPI are about the same. Actully the SOHC seem's to deal with boost better then the Zetec. If it was up to me I'd just stick woth the SPI and put all your money into the tuning and nice turbo hardware
hey hey, i think i might seriously turbo my spi now. just need to know what i all need. know this guy that'll prolly hook me up with a turbo manifold and prolly a downpipe too for around $200. then all i need is a turbo, intercooler and tubing. turbo will be easy, i just need one that'll spool up quick. my friend says just use a mitsubishi turbo from like a gsx or gst eclipse. probably like a $20 junkyard part, or i know i can get a deal from some buddies or whatnot. intercooler piping is where i run into trouble. would i need to weld?? and for ECU and stuff, would i need to tune the cpu?? lemme know. any help on this would be appreciated. thanx in advance
jeffescortlx wrote: With the stock 9.3 compression, 93 Octane gas stock N/A timing (Escort ECU with out the knock sensor) I could run 8psi, anything higher and it was welcome to deto city.
But it's all in the tuning, I had stock ignition timing, with a chip I could have pull some timing and run more boost.
But for me it was cheaper to run low compression, now I run any where from 15-17psi on the street and 20psi on the dyno.
But honestly, if your gonna go turbo there's not much advantage to swapping to a Zetec. Both the stock internals of the Zetec and SPI are about the same. Actully the SOHC seem's to deal with boost better then the Zetec. If it was up to me I'd just stick woth the SPI and put all your money into the tuning and nice turbo hardware
shit didnt read that at first. dude i think your right. someone else i knew said that sohc run better turbo'd than dohc for some reason. i know that sohc civics are usually are more tolerble to boost from what i hear. Now about the stock internals, what about the valve train?? would i need to upgrade that or not unless i grab a new camshaft?? also what about that split port imrc thing?? would i need to disable it or do the swab to tap into some extra power?? i'm also running an auto trans. what would be less expensive, a trans swap to manual, or and auto trans shift controller or something similar, or should i just leave it as is and go mannual when i get the benni's to buy the new manual trans. i seriously think i should fuck the zetec for now and turbo my spi. Now can the SPI handle 8 psi no problem on stock internals?? if so i'm gonna boost it at 8. perhaps a how to should be made on turboing your spi. LOL j/k whould be sweet though.
It would be wise to upgrade the valvetrain with the stiffer springs and titanium retainers.
as far as turbos go, Iw ould not use the mitsu turbom not really the best performer available. I myself am more a fan of the T3.
dont forget that you will need bigger injectors and would benefit from a larger MAF. you will also need tuning, most likely from a chip and SCT proracer package.
as far as trans, the auto wont last long. Ive heard that wil low boost, upgrading the torque converter is sufficient. however, research it more before you go with that.
Dont worry about the valve train, cam, spring's..none of that. Stock is fine. My head came straight from the junk yard with 116k, I did'nt do a damn thing to it and it has no problem with making power and doing it reliably. Head work is not a priority, nice to have if you have money just laying around, but it's not top on the list.
But like TXFO said, get a nice T3, dont cheap out on some tiny blown turbo. Do it right. And add a 5 speed swap to your list of things to do soon. And look in to a MAF, Injectors and Chip (SCT) "MIC".
