I have to be honest i am baffled by turbos. not how they work but the sizing, trims and compressor maps. so anyone know of any reading that will help? i have a T3 from a RST, which im told is borderline size wise from my project, so looking at T34s from RSCs. which i understand is a T4 compressor with T3 Exhaust housing. so do i rebuild my T3 with a new compressor housing and wheel? should i buy an new cartridge unit (what is a CHRA?). or do i buy a T34 for ~ 300 for a used one!! im just puzzled by it all, i dont expect to be a turbo expert, just know a bit more than i do now, to help me make a reasonable decision to start with.
CHRA 'centre housing rotational assembly' As far as I understand, The housing numbers can be related to gear ratios, for example a 0.82 rear housing will spool quicker than a 1.06 Compressor maps are witchcraft. lol
You size a turbo to you requirements. If you want to really work it our you should use the compressor maps, but its hard to do unless you know ve and BSFC of your engine. Most of the time its an estimate. I did the same thing with mine and just fitted it. You have a turbo, might be best to fit it get it running and then once you feel the urge for more, change then. You may find a different turbo changes the characteristic of your engine too much.
Read through the various levels of turbo tech here to get you started. http://www.turbobygarrett.com/turbobygarrett/turbo_tech_basic
I was in the same boat as the OP. I did a lot of reading and can now pretty much look at a compressor map and know if it`ll be too small, the right size or too big and laggy. What they don`t tell you are how well it spools etc. A ball bearing Turbo will spool much quicker than a journal bearing one, but they cost more and aren`t rebuildable. I`ll try and dig out the link I used to help me understand
8V engines and turbos...<sigh> When I did mine in 2006, I did a bit of benchmarking on several JDM 2.0 16v turbo vehicles, i.e. EVOs, Celica GT4, Plusar GTiR, Sw20 MR2 and S14 Silvia/200sx w SR20DET, to correlate my wishes with a drive feel. I worked out my Golf required 280bhp@6400rpm I purchased and read these books: Then I had a play with the calculator in this site. http://www.turbofast.com.au/ From here, I started to collect compressor graphs from turbos that could achieve the BHP equivalent in CFM , efficiently. I also worked out a method to determine VE, which is directly proportional to your torque curve to work out natural engine airflow. Your engine is ~ 80% efficient @ say 4000rpm with a BSFC of @ 0.55-0.65 Have a go at those and then fill in with the turbo of choice and see if it will meet your objectives. Others feel free to chip in.
i know eddie... but i have in my mind planting evil thoughts, that mk1 escort with a 1000bhp pinto in the front that revs to 11000 rpm!! or the Pizzo bros 500bhp VW 8v turbo dragster from the 80's!! i would be happy with a 1/3 of the power at half the revs..... to start with! thanks for the book suggestions.
the A. graham bell book is mega money, if you have one, hold on to it. cheapest i can find on ebay or amazon 139.99 for a used copy!! i can get a new copy sent from the US for $4199.99!!! FFS
im reading maximum boost book now, its a great book so far, not too science like, with good examples.
That is the great thing about books like that. The experienced writer is aware not everyone is scientific and uses his knowledge and translates, what would be fairly complex study, so you the avid reader could comprehend
