ok here we go again... lol. hello to everyone i am new to the forum:)

ok i am going to preempt this with im not crazy, you are not going to change my mind an i want valid intelligent input.

ok so here we go i have been looking into putting a turbo on my 1997 zx7r i have already had it bored out to 942cc polished and stage 2 jet kit this was all dont previously before i bought it by a friend of mine that builds dragster engines (car).

I looked into mrturbo and i cant justify me spending 6k on a turbo kit so i am going to fab my own. im am looking at a garret GT1549 turbo
it is small should spool up fast and give me somewhere between 5-10 ish PSI boost i think. any input on this would be appreciated. so now on to the headers i cant seem to find a 4 to 1 header anywhere so i am prolly gonna have to fab my own which shouldnt be to hard i am an aircraft mechanic and have training in metal working. so now comes the questions.
stock compression on a zx7r is 11.5:1, im not sure what mine is ill have to get a compression tester and find out but that is easy.
i want to run pump gas and to do that i have read the highest compression you can have is 13:1 without intercooling, otherwise you get a premature detonation in the cylinder bad juju all around.
all my figures are based on a stock engine until i actually check my own. ok so from what i calculate to run a boost of 7 PSI safetly at an altittude of 2100 feet (Las Vegas)i would need to drop my compression to 9:1 by adding a spacer to the header. if anyone know how to figure out how much i need to add a formula for that would be great. that would make my new compression to 12.87:1 running 7psi boost. i plan on controlling the boost with the built in wastegate on the GT1549. is it a good idea to run so close to 13:1 or should i try to aim to keep it at 11.5:1. to keep it at 11.5 :1 i would have to alter my static compression to 8:1 and that would give me a boost compression of 11.39:1 but 8:1 seems pretty low i dont even know if a bike can run that low...any thoughts, feelings ...

ok second problem do you think that the stock oil pump is going to be able to pump for both the engine and the turbo? if not then how would i go about fixing that?

im sorry im kinda scatterbrained and i cant write for crap but i hope this at least gets my thoughts across so any input people have let me know (please none of this just go buy a zx10R i dont want one and i just enjoy projects and want to try new stuff)

There is really more involved than the static compression ratio. It's actual cylinder pressure that's important. That engine has a relatively low cylinder pressure at the rpm range that is most critical for a pump gas street turbo. You also don't want to lose too much off boost power. Therefore, I would not drop the static compression too much. A true static ratio of about 10-10.5 should be about right. That, and advancing the exhaust cam should give you good results, and allow 6-8 pds boost on pump premium.

Now for what you don't want to hear. The bottom end on that engine is pretty weak. The crank is not well supported and flexes. Stock rods, and more particularly rod bolts will NOT hold up long with a turbo. Even with good rods, it's not an engine I would build very far, and certainly not turbocharge.

Cary

A quick edit when I said add a spacer to the header I meant to type cylinder head

welcome to the forum sincityzx7r, check out the member intro thread and introduce yourself, post some pics of your bike too. sorry i don't know anything to help your situation but enjoy the site and let me know if you need help with anything else.

ok well the first part was good news ....the second part is not so much lol. i talked to the guy that built the engine and he said that when it was bored out they replaced the stock connecting rods. anywho, i bought the bike for 2500 (friend discount and the fairing has some road rash) so i think im still going to press on and see what happens.
as couple more questions, when i build the plenum to connect to the carb is it a good idea to just alter the stock airbox or should i fabricate it out of metal?
also what is the ideal fuel/air mixture i want to have with a turbo system?
and how would i go about changing the exhaust cam that you talked about?

You've got to have a metal intake plenum.

As to the cam timing, just get some adjustable cam sprockets. It's really part of the normal engine build, and you may already have them. If you run a base gasket spacer to reduce compression, that will alter cam timing anyway, so you will have to re-degree them. All I was referring to is that with a turbo, you normally advance the lobe center on the exhaust some, depending on the engine, the comp ratio, and the amount of boost you intend to run, from normally aspirated settings. You would also retard the intake in some cases, but here I would not.
I have those lobe center numbers on file, and can look them up when you are ready.

Again, though I really hate to disscourage you, this is NOT an engine to turbocharge. Really.

Cary

Ok the logistics of this do seem like they are going to get pretty rough. What bike would be good to turbo besides the normal hyabusa or zx14?
Or what modifications could I do NOS doesn't seem very streetable unless there is a way to do a progressive shot or something?

hahah i was just looking at your profile and the friend of mine that does the drag engines is in sullivan indiana mike doerner, and a buddy of mine growing up was from decatur indiana cant remeber his last name though first name was chris anywho thats kinda ironic

NOS is very doable. You can use a mild shot. You could also set it up as a progressive system, but that's a bit more expensive. In any case you would not want to use all that much anyway.

There are problems with making big power, via turbo, or other means, with many of the bikes from the 1990's. They were a a bit weak in many areas, and while you could safely make a moderate amount of more power, really good gains caused trouble. Fixes are available for some areas, but it can get very expensive.

Cary