wwg6983

I checked the forums and found out a few things

Stock Compression is 10.5:1
Thats a little high right?

Mr Steve said he boosts 5-7 with out inter cooler
and 8-10 with inter cooler. Thats alot of PSI for an already high compression engine. How long do you do boost that much and how reliable is it. Do you lower it for normal day to day driving ? My friend has a Nissan240SX with a Japaneese made SKYLINE engine dropped in. his engine is 8.5:1 and he boosts 15 psi. His engine is Stock Turbocharged so its made for this. Thats why I ask this.

Im just trying to figure all this out. I have searched the forums and done some reading. So try to enlighten me please.

2ND_TIME_CLS

I'm not a turbo expert and can't speak for Mr Steve but I believe the key to more boost and reliablity for a CL is to drop the compression with custom pistons and also add some stronger rods.The only thing is I'm not to sure how hard it is to do that stuff to a CL????A Nissan 240SX with a red or black top SR20DET only needs a bigger turbo to hit 12's but your friend has a Skyline motor in it,is it a RB26DETT???With a CL its just gonna cost you so much to be able to run alot of boost safely unless you do all the work yourself and get parts cheap,you can also and a water injection kit and that will lower your compression.then you need a fuel pump,maybe MSD,front mount intercooler or air to water intercooler,metal head gaskets,stronger head bolts,and so on and so on!!!

babyblue

Don't know where you got your info but currently I have the comptech SC setup in my car with the High Boost Pulley... Boost is around 5.5-6.5 psi on WOT. If I go with Scalberts IC Kits, and change the Alternator Pulley with E-Manage I can boost the car up to 9-10 psi of boost. Scalbert dyno'd his car with the IC Kit and was around 355 whp if I am not wrong.

Allmotor has a turbo setup, with Scalbert IC Kit is running around 5.5 psi of boost and got 419 whp.

Both of these setups are using STOCK internals... Everything has been bolt ons, no custom internal rods or pistons. Many of them have had boost for a while and have had no major issues. The SC won't need any maintainence till 80-100 K miles and comes with all the components you need for your SC install.

wwg6983

I got my info from a Few Forums. I did a search and saw one asking about Stock compression, then a few more talking about SC Boost. I plan on getting a SC'er and want to get as much bang for my buck with out causing dmgs to my engine. Thanks for the Info. I will do some more looking into it and hopefully get a few more replies as well as talk to my nissan friend and see what the consensus is. I do appreciate the info.

allmotor_2000

Actually I have a completely different IC setup (air-to-air with a FMIC). Anyways, the key to turbocharging is controlling heat. You can boost on a 10.5:1 motor... just need to watch timing, cylinder-temps and AFR.

Rods/pistons arn't necessary until 15-20psi when cylinder pressures are so high that you see metal fatigue. However, bad tuning, detonation etc. will break any type of piston, rod etc.

I boost ~6psi for > 20K miles. It's a very high-flow turbo, so there's a LOT of air being pushed through. No problems so far.... I think this motor can reliably push 450whp with a few more mods on 91-octane.

babyblue

My bad allmotor I thought you were using the same IC Kit

02AV6

It's typically stereotype that you can't run boost on high compression.
Current M5 with 11.0:1 CR will be offered if not yet 7psi intercooled supercharger kit.
So as long as your AFR is safe with help of cooling and fuel management you can run up to the certain psi on stock internals. And obviosly with upgraded low CR internals you can run crazy amount of boost, however again as long as AFR is safe.

wwg6983

Again thanks guys this clears up alot of confusion. I really appreciate the help.

rlpierce04

How would you manage AFR to keep it in a safe range? Meaning what parts would I need to get?

bigguyonbike

scalbert has been able to intergrate e-manage to are cars using a harness he produce. with this you can control fuel, timing, airflow sensors, and many other things. you also need some way of see the AFR and that can be done with a wideband o2 monitor or a dyno facility with A/F reading equipment.

2ND_TIME_CLS

has anybody ever dropped in custom rods and pistons on a CL to lower compression????