Id like to know #'s.
Or just how bad you think it was, if bad at all.

Reason is I just picked up a low mileage Z1 block.
And I want to put it in as is.
With my head combo the comp will be about 7.7:1.

Thank you.

Personal experience would be great, a guessing game isnt what Im looking for.

 

I ran my B16 at 7.8:1 compression for a while, it didn't feel too bad off boost. Lots of people on here are going to tell you how shitty it'll feel off boost, but 99% of the people on here probably have not driven a low compression honda off of boost. If you feel it's driving like crap on the street, put in a thinner headgasket or mill your head, or both.

 

I dont care how it feels off boost.
As long as on boost, Ill still get a nice kick in my pants.

What turbo were you using ? And ever dyno it ?

Thanks for the reply.

 

Uh oh.......here comes the Compression ****.

 

Ryan im with you man, I love compression in every setup.

But I just spent 100 bucks on this clean block, and I wanna put it to use.

Ya know !

 

Use it and just throw some boost at it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dr. D-Series &raquo;</TD></TR><TR><TD CLASS="quote">Ryan im with you man, I love compression in every setup.

But I just spent 100 bucks on this clean block, and I wanna put it to use.

Ya know !</TD></TR></TABLE>

LOL, I was referring to b16coupe, him and I have had some arguments about what C/R to run with turbo.

 

Well kiss and make up.

Im the center of attention now. Haha

Rofl

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b16coupe &raquo;</TD></TR><TR><TD CLASS="quote">I ran my B16 at 7.8:1 compression for a while, it didn't feel too bad off boost. Lots of people on here are going to tell you how shitty it'll feel off boost, but 99% of the people on here probably have not driven a low compression honda off of boost. If you feel it's driving like crap on the street, put in a thinner headgasket or mill your head, or both.</TD></TR></TABLE>

exactly. There's a certain value which is ideal yada yada yada, but when it comes down to it, it's not life or death

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dr. D-Series &raquo;</TD></TR><TR><TD CLASS="quote">Well kiss and make up.

Im the center of attention now. Haha

Rofl</TD></TR></TABLE>

lol!

 

Keep it coming !

Thanks for the bump skittle.

 

I was running an SC61E turbo on an inline pro log mani, spool up compared to stock 10.2:1 compression was exactly the same. My motor is in an EF sedan, and it pulled a bit on a friends EG making 410 WHP.

I prefer a lower compression motor for the street, especially if you're running a D-series motor, because I would gladly sacrifice a pinch of low end power so that I can run a few more pounds of boost on pump gas and get some more top end power out of it.

 

Thanks for the input.

 

bumping or lowered the compression a point or two shouldnt make a noticable difference in spool time.

If all you are worried about is in-boost performance, I say go for it.


Just remember, D series transmissions are gayer than south beach and that you should consider a decently spooling turbo if your running a z6/y8 trans

 

**** it, ill do it.
I had my b7 block all cleaned and painted.
I guess its gonna be a big paper weight in my room now.

Ive got a z6 trans, and the snail is a ***** 42/48. Will spool up fine.

Thanks.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dr. D-Series &raquo;</TD></TR><TR><TD CLASS="quote">**** it, ill do it.
I had my b7 block all cleaned and painted.
I guess its gonna be a big paper weight in my room now.

Ive got a z6 trans, and the snail is a ***** 42/48. Will spool up fine.

Thanks.</TD></TR></TABLE>

Yeah that turbo will spool up REALLY quick. A good upgrade is the 60 trim T3 (.60/.48). There's a large noticable difference between the two. Spool up is still quick.

 

I had a 60/63 on my last 10:1 setup.
But it was blowing oil like it was going out of style.

So I still have the 60 compressor housing and wheel and will upgrade sometime in the future.

 

yeah mine blows oil like crazy too haha

 

You challenging me ?
My 60/63 was so bad, I could pour almost a 1/4 quart of oil out of my charge pipes.

Im not lying !

Haha

 

Evans tuning had a 10:1 vs 9:1 dyno comparision. Lost ~14hp. I had an old sohc with like 8.7:1 and i hated it. Zero power on the low end. Im much happier with my 9.4:1. Sohc needs all and any power you can get with no boost help.

http://www.evans-tuning.com/viewtopic.php?t=1612

liam

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by liam821 &raquo;</TD></TR><TR><TD CLASS="quote">
Evans tuning had a 10:1 vs 9:1 dyno comparision. Lost ~14hp. I had an old sohc with like 8.7:1 and i hated it. Zero power on the low end. Im much happier with my 9.4:1. Sohc needs all and any power you can get with no boost help.

http://www.evans-tuning.com/viewtopic.php?t=1612

liam</TD></TR></TABLE>

How the hell can you say that after seeing that graph? The difference off boost is like 3-5 WHP, and that's a full point drop in compression with a motor that started off with more N/A horsepower. A drop in compression in a motor making less horsepower will have a proportionately smaller drop in power. If you think your 9.4:1 setup feels so much better than your 8.7:1 setup, 95% of it is all in your head.

 

I agree.

BTW I pulled the head off.
The block is ******* mint.
Cross hatch is so visible you can see it 20 feet away.
Its a "JDM D15b". But its a Vtec-E so basically a vx. P07 stamped everywhere.

Cant wait to put in a almost NEW motor.

 

i ran a vx bottom end with a a6 head.it wasnt bad but i was running 15-20 psi
on a t25. it was fun ran 12.98 at 105 on street tires in my ef hatch.lasted about 14,000 miles not bad for a throw away motor.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by @lbert &raquo;</TD></TR><TR><TD CLASS="quote">

How the hell can you say that after seeing that graph? The difference off boost is like 3-5 WHP, and that's a full point drop in compression with a motor that started off with more N/A horsepower. A drop in compression in a motor making less horsepower will have a proportionately smaller drop in power. If you think your 9.4:1 setup feels so much better than your 8.7:1 setup, 95% of it is all in your head.</TD></TR></TABLE>

Your right - off boost power isnt much different. I was talking about on boost power however. Which still isnt that much.

Even if it was 5hp, your talking 5% power loss with a sohc.

However trust me, my old lower compression motor was a dog without the help of a turbo.

liam

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by liam821 &raquo;</TD></TR><TR><TD CLASS="quote">

Your right - off boost power isnt much different. I was talking about on boost power however. Which still isnt that much.

Even if it was 5hp, your talking 5% power loss with a sohc.

However trust me, my old lower compression motor was a dog without the help of a turbo.

liam</TD></TR></TABLE>

Considering out of boost hp on a SOHC is probably between 40 and 70whp, not 100whp, 5whp is alot more than 5%. It's more like 7-12% loss in power, which is alot. If you put a good CAI, header, and exhaust on an N/A SOHC you probably won't even gain 12%.

Everyone simply thinks "What does a 5hp loss out of boost matter on a turbo car making 300whp+, it's just 5hp?" Well, 5 hp is alot when you're only making 70whp at your current rpm/load. This is why anyone that thinks 1 point of compression drop will have minimal affects on acceleration, throttle response, and spool up is just plain wrong.

 

Compression doesn't have any effect on spool. Reading that thread on Jeff Evan's board shows spool up is identical between 9:1 and 10:1

My point is a full point drop in compression isn't going to cost you 5 WHP be it a D-series or a B18 or an H22, losses in power from a decrease in static compression will be a percentage and linear based on how much power your engine currently makes. So 5 WHP off boost might be 3% on a motor making 150 WHP originally, so start off witha motor making 90 WHP and you might lose 3 WHP. I own a high comp turbo car, I have friends that own low comp turbo cars, and they're so similar that I just don't think you can say that 7 tenths of a point in compression changes your car from feeling like a dog to feeling awesome on the low end.