Phill106 Posted August 14, 2015 Share Posted August 14, 2015 (edited) I don't want to flood this section with my questions so I thought I'd try to contain them just to here lol I have a few questions about a potential gsxr 1127k turbo project. Will a garret gt25 too small To hit 250bhp?Will I have to do any work to the standard carbs to use them as blow throughs? I think I read somewhere the diaphragm top cap needs to be changed for a metal one? If so any links would be good. What at sort of pressure fuel pumps should I be looking at to overcome boots pressure? Can I go too high? Edited August 21, 2015 by Phill106 Quote Link to comment
Gixer1460 Posted August 14, 2015 Share Posted August 14, 2015 Depends on what GT25 you select ! Personally I think a GT2560R would do it but not ideally suited - I'd prefer a GT2859R or 60R unless you want to run lots of boost (and therefore heat!) all the time?Std. plastic topped CV36's will hold boost for a while but will eventually let go - swopping 'down' to tin topped 34mm CV's is usually bombproof.Again its down to what boost you are running but usually a smallish EFI pump and good regulator is required with a fuel return to the tank - must work at 2psi ie. off boost upto 15-16psi @ 1bar or more?Again, personally - an EFI system saves on engineering over a lot of these issues and releases more usable power through more accurate control of fuelling and timing! Quote Link to comment
Phill106 Posted August 14, 2015 Author Share Posted August 14, 2015 Do the smaller throttle body's have a restrictive effect on power? Quote Link to comment
Gixer1460 Posted August 14, 2015 Share Posted August 14, 2015 Subtle difference - throttle body is a fuel injection part, carbs are carbs. Due to the restriction of the turbo the smaller bore carbs will draw better off boost and the turbo will pump air to make the real power. Quote Link to comment
Phill106 Posted August 17, 2015 Author Share Posted August 17, 2015 Cool cheers. I'm just worried I pick something too small or too big haha I think I read somewhere I shouldn't be running much more than .8bar? Quote Link to comment
Phill106 Posted August 21, 2015 Author Share Posted August 21, 2015 Iv decided I'm also going to increase the cc to 1216 as iv chanced upon a very cheap set of busa Pistons with rods. Just wondering if I need to lower compression when turboing? And if so will longer rods and the bigger cc be enough? Quote Link to comment
Gixer1460 Posted August 21, 2015 Share Posted August 21, 2015 (edited) Can't use the pistons AND rods in a GSXR 1100 - they are too tall unless you want to machine the crowns but by the time you put enough dish in there, there wouldn't be much crown left for turbo use! Just use the pistons on 1100 rods - they aren't ideal as the squish is to big but they give a turbo friendly compression that can be played with using base and head gasket thicknesses! They'll take a bit of abuse, hold up to 300hp if set up correct but the ring land is a bit thin so detonation will kill them double quick. Oh other thing - they need to be early Busa pistons - later mk2 had 18mm pins........1100 has 20mm!Regarding compression it depends on how much boost you use! Low boost 'can' work with stock 10.5:1 CR but most can't stay low boost so some lowering is enevitable - I have approx 9:1 in a 1460cc motor that will pull over 2 bar boost but uses lots of tricky stuff to do it! Edited August 21, 2015 by Gixer1460 More info 1 Quote Link to comment
Phill106 Posted August 21, 2015 Author Share Posted August 21, 2015 Any idea what sort of power that standard Pistons will take before failing? Quote Link to comment
Phill106 Posted August 21, 2015 Author Share Posted August 21, 2015 they need to be early Busa pistons - later mk2 had 18mm pins........1100 has 20mm!...fuck. Lol Quote Link to comment
Spondonchris Posted August 22, 2015 Share Posted August 22, 2015 Standard pistons dont like boost. They wont last long if you run much boost, just change em. Quote Link to comment
vizman Posted August 22, 2015 Share Posted August 22, 2015 (edited) my standard b12 lump was running about 6psi.....loopie said it won't last long....I turned it up to about 9 ish and it lasted about 9 miles....so we put some busa slugs in. Edited August 22, 2015 by vizman Quote Link to comment
Paulm Posted August 22, 2015 Share Posted August 22, 2015 Yep mine was the same,stock Pistons didn't like 15psi! Lol Quote Link to comment
Phill106 Posted August 22, 2015 Author Share Posted August 22, 2015 Lol ill definitely changing those then. I was planning to run 8-11psi. Will 1127 rods and crank be able to hold? Quote Link to comment
vizman Posted August 22, 2015 Share Posted August 22, 2015 yeah rods and crank are up for the job.....well depending on how much want to be kicking out bhp wise Quote Link to comment
Captain Chaos Posted August 22, 2015 Share Posted August 22, 2015 I was planning to run 8-11psi.famous last words 3 Quote Link to comment
Phill106 Posted August 22, 2015 Author Share Posted August 22, 2015 famous last wordshaha well my friend is currently trying to persuade me to buy his old turbo from his 450bhp skyline so we will play it by ear haha 1 Quote Link to comment
Phill106 Posted August 22, 2015 Author Share Posted August 22, 2015 yeah rods and crank are up for the job.....well depending on how much want to be kicking out bhp wiseid be more than happy running 200-250bhp but there's something magical about the 300 mark lol Quote Link to comment
vizman Posted August 22, 2015 Share Posted August 22, 2015 you want 200+ you better like spending money Quote Link to comment
Phill106 Posted August 22, 2015 Author Share Posted August 22, 2015 (edited) Don't worry I'm expecting to triple my original budget haha it'll be a slow build over the winter plus the misses has given me free rain get and do what I want with it haha Id hate to think what you've spent to get where you are with yours lol Edited August 22, 2015 by Phill106 Quote Link to comment
Phill106 Posted August 22, 2015 Author Share Posted August 22, 2015 My bad I thought @gixer1460 had posted that haha Quote Link to comment
Duckndive Posted August 23, 2015 Share Posted August 23, 2015 haha well my friend is currently trying to persuade me to buy his old turbo from his 450bhp skyline so we will play it by ear hahaIf its a ceramic one then I would give it a miss............... Quote Link to comment
jrhartley Posted August 23, 2015 Share Posted August 23, 2015 I have stock suzuki cast pistons in my 1127 turbo bike, use up to 18psi.Its been on the road for years, never had it apart.It does does have a intercooler....A good tune is the key to a healthy motor, forged pistons only give you a margin of safety, they won't last if the tune is off! Quote Link to comment
Gixer1460 Posted August 23, 2015 Share Posted August 23, 2015 Turbos are relatively soft on rods and generally its lubrication failure or deficiency that kills them so that is the one critical area to make sure is right! And yes phill106 it was a big money build and well into 5 figures - mostly not by me happily! Quote Link to comment
slingy1157 Posted August 23, 2015 Share Posted August 23, 2015 I have stock suzuki cast pistons in my 1127 turbo bike, use up to 18psi.Its been on the road for years, never had it apart.It does does have a intercooler....A good tune is the key to a healthy motor, forged pistons only give you a margin of safety, they won't last if the tune is off!got any pictures of your system and intercooler setup JR? Quote Link to comment
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