need some help with si head and turbo
 

Hey guys please forgive me for i am new to the honda scene. I have an '88 CRX of which my friend says has an hf motor with an SI head... but it feels pretty slow. The Si is the faster model correct? The engine code is a D15b6? and the head is off of a SI motor non vtec? So not all SI heads are Vtec? With this supposed set-up what kind of specs do you think i would have with this motor.

1. What is redline (my tach doesnt work) but it says it goes to like 5,500. But my buddy says with the si head it will go 6200rpm safely.

2. Whats an estimate on horsepower with this kind of set up?

3. and is this set up safe to boost?

4. if so, what route would you go thats the cheapest and safest. just looking for some more power to get around on the freeway so that i dont get crushed by huge SUV's. and i hate driving slow.

Thanks in advanced for your help its deeply appreciated and sorry for the trouble. New to the scene and it seems like theres so many different combinations of head and block set ups. Si non vtec, Si Vtec.... D series, b series,

Thanks again,

Jon

Re: need some help with si head and turbo
 

Oh god, it's new years at 7am. This is probably the only time you'll get this response. :1


The 88-91 civics didn't come with vtec. That started in 92.

The Si was a 1.6 non-vtec, and you have a 1.5 non vtec. Not much of a difference, but there may be rod/stroke/compression differences, but you'll be fine turbo with that motor.

Not sure what the Si redline was, but 6,200 rpm sounds pretty reasonable for the motor.

For off the line power, but not a large top end you can go with a T25 or 14B turbo off 1st/2nd gen. eclipse's. For nice top end with a little bit more lag down low you want to go with something like a 48/60 or 63/60 T3 turbo off an old T-bird. If you want something between those sizes and want good all around power, go with a 42/48 T3 turbo off a volvo or saab.

For cheap, go with a log manifold, 1st gen eclipse blow off valve, custom coach intercooler, eclipse turbo 450cc injectors, chip the ecu with turboedit, make some charge pipes, and larger exhaust, and get some oil lines (this one guy named Stealthmode sells them) :P

Ok, I've said too much.

Re: need some help with si head and turbo
 

noob, look at the title of this forum. What kind of question are you asking? turbo. exactly, throw it in the turbo section next time. Not to mention, post count=1, that means your first post should be in the general discussion forum to introduce yourself to everyone and so hotrex can flame you. Also, all noobs need to post porn. oh yeah welcome to hmt O0

Re: need some help with si head and turbo
 

Well, not all of his questions were turbo-related. Si's redline is 6500 rpm. I know this cause i just looked at my 91 Si just to make sure. I'm not sure of exactly the hp #'s of the Si were, somewhere around 109 or 110 i've heard, but probably a little less due to the fact that your bottom end is a d15...less displacement by means of less stroke. If you wanted to spend a little coin, you could invest further into a "mini-me" head swap by putting a d16z6 sohc vtec head on your block, and then spin it to 7500 with the right ecu and setup. That would jump you up to around the 130'ish mark due to a slightly higher compression and the addtion of vtec. It would be enough to make it a little more managable on the highway. Or you could just turbo the existing motor. Also check the ecu numbers and see what ecu that is in it. I'm not sure what the hf model ecu code is, but the Si's ecu should be a pm6. There should be a label on the side on the ecu that reads something like "37820-PM6-A09". That's actually what the side of my 90 si ecu reads, just look for the middle set-2 numbers and then a letter. It may even add a little more pep if it turns out to be the hf ecu by swapping in the Si ecu, as i'm sure the fuel and timing curves are way different between the 2. Either way it's gonna start to add up to some money to make more power, these are just some of the cheaper alternatives.

Re: need some help with si head and turbo
 

Stealthmode and slo_crx1 thank you very much for your help. the information you have provided is making sense. Because since the head swap was done, i havent felt a huge difference yet... so my friend also mentioned swapping the ecu or computer thing.

As for the turbo goes, im thinking about going with a T3 with my hf manifold going through a 2.5 inch exhaust and a boost controlled cut-out.


JDMFantasy2K - The reason why i put this post in the hybrid section was because most of my main questions were based on the hybrid of the different SI heads and my D15 Block. Even if i do go turbo, (which is why i asked the questions) I believe that it is still a hybrid and technical topic to discuss. So if i posted this in the forum mistakenly then im sorry that i offended you and please move it to where it belongs but yes it was a simple noobie mistake.

Thanks for the help again guys.

Jon

Re: need some help with si head and turbo
 

"ecu or computer thing" thats great. :8

Re: need some help with si head and turbo
 

im not exactly down with all the new terms yet....