Am i cool witht these compression numbers?

[JoeyJigglesGSX]

The one thing i have no knowledge about yet is my engine internals. I am about to put a FMIC, ACT 2600, and have it re-dyno tuned. Before i did this i wanted to make sure everything was still cool, so i had a compression test done. They said that i have 150 all the way across except for cylinder 2, it is at 145. Again, i have NO IDEA about this crap. I have had problems with boost creep in the past and the shop said it may have been part of the reason. Is my engine still cool to go on for more boost (about 19 or so) and these mods? or should i just stop? please help me out with this...thanks

 

[FORMONTOYA]

You should not have more than 14psi difference between cylinders, which you don't.
The standard compression is 178psi.
The service limit is 133psi.

I'd say you were roughly in the middle of the high and low with one cylinder a touch low, but nothing to worry about yet. You could always do a wet check just to verify though.

Both methods found here:
http://www.dsmgrrrl.com/FAQs/compression.htm

 

[JoeyJigglesGSX]

so would you continue with the mods i have listed? or should i just think of a different car?...i know that sounds really dramatic, but i am just wondering...again i dont know how serious this is

 

[FORMONTOYA]

The numbers aren't horrible and I wouldn't have a problem with a little modding on that engine, as long as you don't beat the living crap out of it I would think it would last a while. However, I would also start an account for when the bottom end does need a rebuild, or at least start looking for the best mod for a DSM.....a beater to get you to where you need to go when the toy craps out.

 

[JoeyJigglesGSX]

again, baby me here...haha...when you say it will need a rebuild? what are we talking about and money wise?

 

[TSIMonsteR]

You do have fuel mods right?

 

[FORMONTOYA]

At some point any engine is going to need to be rebuilt. A lot of factors go into when that happens. The main one is how well you maintain it. The next one is how bad do you beat on it. If you go about it the "correct" way and follow the upgrade paths on this site or many others you will at least have things in place that will go a long way in lengthening the life span. Of course with these cars (turbo) maintenance is a must, and plenty of it. You can beat on these cars pretty good as long as you follow the 2 things listed above. If you slip on either one you will be doing a rebuild sooner than later.

A rebuild depends on how bad the damage is, but to me a total rebuild would consist of removing the engine and basically stripping it down to the bare block and then replacing just about everything that's bolted on...rings, bearings, seals, pumps, belts, pulleys, etc. The price would depend a lot on whether you do a majority of the work or if someone else is doing all the work as labor rates are pretty expensive. Also a lot of the difference in price is going to be what your goals are....speed cost money, how fast do you want to go?

If I had to guess what the cost would be for a total bare block rebuild without any labor done by you I would ballpark it around $2500. But then again I don't know for sure as I have not done a total rebuild recently, however I did a top end rebuild recently and spent about $800 (TB/BB parts, head gasket set, various other knit-picken things) for parts and had a buddy that actually refreshed the head for me for the cost of the seals (which I already had and supplied him with) plus $100, I did all the other labor involved myself.

 

[IMSmotorsports]

i had similar compression numbers and i was making 355whp on pump gas all day long (20psi) and over 400whp on race gas with a stock 7bolt (arps and 4layer plus cams). 100k miles where on that motor as well.

 

[FORMONTOYA]

honestly i think your being a little paranoid i had similar numbers and i was making 355whp on pump gas all day long (20psi) and over 400whp on race gas with a stock 7bolt (arps and 4layer plus cams). 100k miles where on that motor as well.

And there you go...someone that's gone through a similar situation as you. These engines are pretty hearty as long as you follow a few simple rules....
1. Upgrade path, don't slap on that big turbo until the supporting mods are in place.
2. Maintenance
3. Maintenance
4. Maintenance
5. Maintenance

 

[alex]

1. Upgrade path, don't slap on that big turbo until the supporting mods are in place.
2. Maintenance
3. Maintenance
4. Maintenance
5. Maintenance

You are SO right.

DSMs just need a little lovin'.

You are fine with those compression numbers, decent and stable numbers by the way too.

 

[FORMONTOYA]

Oh yea, I just comprehended the boost creep issue...IT ISN'T RELATED TO YOUR COMPRESSION NUMBERS. Boost creep has more to do with the internal waste gate opening and exhaust.

 

[JoeyJigglesGSX]

i do have fuel mods...550 injectors, 190 fuel pump and an SAFC II tuned...but thanks a lot guys for all of your help especially FORMONTOYA...i feel a lot better, and i feel MUCH MUCH better after hearing what IMSmotorsports had to say...i guess i will go along with my goals of putting my FMIC, Flywheel/ACT 2600 and re-tune...thanks again guys

PS- yeah that whole boost creep thing, i sort of wanted to kill myself with it all...the only way we got it resolved was to put in a 2.5" downpipe and high flow cat...i know it sounds crazy , but we did every bit of porting there was to do, followed pictures right from Road Race Engineering too...the shop i went to was an experienced DSM shop and they said they have never seen a car like this before where they could not stop the creep...they would unbolt, port, try it out, unbolt, port, try it out, then 2.5", try it out, then high flow cat and it finally stopped...sucks for me i guess...

 

[alex]

Sounds good! Goold luck with future mods and hopefully she'll take care of you well......and of course, you'll have to take well care of her too Joey. Just make sure you keep a bottle of Asprin in the glove compartment