325 turbo confusion!?

Post Sun Sep 16, 2007 4:41 pm

Thats the general opinion, obviously stretch bolts can be a weak point in thier very nature.

I remember reading in a (uh hum) Fast Ford magazine about a Swedish guy who got 1000 BHP out of his YB engine by raising the compression ratio. Admittedly it was a highly modified cossy engine, but it was done nonetheless. Another thing to consider is what the head and manifolds can flow, obviously too much spent gasses left over from the last power stroke can cause det and overheating problems.

On top of this, you have to have a decent intercooler or charge cooller.

Post Thu Sep 20, 2007 7:29 pm

i think the intercooler is my weakness at the mo. Im using a 200sx s14a standard intercooler, which i know can take almost 300bhp but as its a 6 pot im thinking im gonna need to upgrade, after doing the clutch and a propper exhaust and bla bla bla! This project is bigger than i first expected, would have been cheaper to drop an rb25 skykline engine in!! My student budget cant cope! As it goes, when i finally get it running, im just gonna wack it to somwhere just under a bar and if it blows it blows!

ant.. if your reading this, with your map, and non strecth bolts and a thicker steel head gasket, what boost can i run with risking blowing it up in the first two months!???

Post Thu Sep 20, 2007 9:15 pm

One of the 1st mods on the 200SZ is to throw the standard intercooler over the nearest hedge and fit a larger front mount. If these guys are doing that to a 4 pot 1800/2000cc engine, it certainly won't be enough for your 2.5 6 potter IMHO. I've found that is not so much depth, but surface area is what you need in an intercooler to cool the charge temps, well thats what she says!

Post Thu Sep 20, 2007 9:34 pm

jondrift wrote:yea i guess so!

thanks for your help guys

just need to find out for definate if im low or high comp!

Im my experiance the ONLY way to tell if you have high or low comp engine is to take the head off and check the pistons, its that simple.
I dont know about this K thing??

I've had endless ammounts of M20's apart and there really is no rule about the compression. The last 3 i've had open have all been from late cars (tourings in fact so all facelift) and have all had the early higher compression pistons.

HTH

Tom

Post Thu Sep 20, 2007 9:36 pm

tomson wrote:
jondrift wrote:yea i guess so!

thanks for your help guys

just need to find out for definate if im low or high comp!
Im my experiance the ONLY way to tell if you have high or low comp engine is to take the head off and check the pistons, its that simple.
I dont know about this K thing??

I've had endless ammounts of M20's apart and there really is no rule about the compression. The last 3 i've had open have all been from late cars (tourings in fact so all facelift) and have all had the early higher compression pistons.

HTH

Tom

Thats thrown a spanner in the works

Post Thu Sep 20, 2007 9:37 pm

ShepsEvo3 wrote:
tomson wrote:
jondrift wrote:yea i guess so!

thanks for your help guys

just need to find out for definate if im low or high comp!
Im my experiance the ONLY way to tell if you have high or low comp engine is to take the head off and check the pistons, its that simple.
I dont know about this K thing??

I've had endless ammounts of M20's apart and there really is no rule about the compression. The last 3 i've had open have all been from late cars (tourings in fact so all facelift) and have all had the early higher compression pistons.

HTH

Tom
Thats thrown a spanner in the works

oops, sorry

Just sharing my findings Paul

Post Thu Sep 20, 2007 9:47 pm

want reliable M20 turbo to be reliable, then rip it apart and invest the money on decent low comp pistons and ARP bolts, studs etc to it will last longer.

for the track, safe mapping and cooling is your main concerns. big alloy intercooler and big rad are essential.

Post Fri Sep 21, 2007 10:07 am

all i can say is student = no new pistons

ill just see what happens!

Post Fri Sep 21, 2007 10:08 am

just out of interest, what do low comp pistons look like??

Post Fri Sep 21, 2007 10:17 am

These are M30B34 low comp pistons.

HTH, Mark,.

Post Fri Sep 21, 2007 11:12 am

i dont have the car here, what is the difference between the high and low so i can describe it to the garage?

Post Mon Sep 24, 2007 8:13 pm

HI , ive got a F reg 325ise, the engines been rebuilt so its got about 10,000miles ive put a t34 turbo on it and running abot 5psi and it keeps blowing the head gasket so ive orded a new gasket and got a 2mm decomp pate and ive been told to use non stretch head bolts but not sure where abouts to buy them from or how much they are do you think this set up will be ok am also useing a ecu and the airflow meter. i know alot of people are usin megasquirt but am not sure where to buy it from or how much it is or how hard it is to set up.cheers

Post Mon Sep 24, 2007 8:25 pm

you should be looking at the turbo info thread.
all the answers are there.

Post Sun Sep 30, 2007 12:29 pm

i know i was told that without megasquirt or some kind of managment its going to run like shit! Are the head gaskets that your blowing standard ones just out of interest? 5 psi sounds quit low to blow them? Im only learning myself but everyone says its mostly to do with how you map it and if yours is standard thats most likely the problem?