The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support Morrison Fabrications
Please Support Fuel Injector Clinic

Stock rebuild w/ NOS 50 shot safe ?

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

ShadeTreeDSM

15+ Year Contributor
269
0
Sep 16, 2005
Fort Lauderdale, Florida
looking to spool my turbo up a little quicker and looking for better ET's. Im on a Garrett 57 on 25psi. I made 455 on a 2 wheel dyno. I just rebuilt my engine stock 4000 miles ago. I got better pistons rings than stock, total seal piston rings, good for boost and NOS according to total seal tech. Also have ARP everything, cometic HG, 150 psi compression across all 4 cylinders. i was thinking of a small shot of NOS, maybe a 50 shot. would it be safe or should i go lower to like 35 shot?
 
For 4k miles on the rebuild 150 across seems low. You should be at least 20-30 higher.

If you are on stock rods then you are around the threshold for power and I would not recommend any more power to them be it nitrous or boost.
 
I agree 450 is all the higher i've ever herd for stock bottom end. I'd invest in some forged pistons and rods
 
For 4k miles on the rebuild 150 across seems low. You should be at least 20-30 higher.

If you are on stock rods then you are around the threshold for power and I would not recommend any more power to them be it nitrous or boost.

im on a 6 bolt engine guys, if you research there is people who have made over 500 wheel on stock engine, closer to 550 actually. and 150 psi across the board is because i have stock pistons which are 7.8:1 (or 8:1) compression. i could always lower my boost to compensate for the added NOS, id be making the same power but with a quicker spool up. id like to see some comments from 1G guys that have experience with NOS :hmm:
 
I have a 6 bolt as well buddy :thumb: and the 150 compression is for how well it's sealing, not the CR of the pistons. Also, those people are really pushing their luck too. You can't go much higher than 450 on stock 1g rods.

You mean nitrous right? "NOS" is a brand name.
 
I have a 6 bolt as well buddy :thumb: and the 150 compression is for how well it's sealing, not the CR of the pistons.

yea compression ratio does make a difference buddy. and i still have low miles on the engine, the compression is only gonna get better by putting more miles on the engine. it may also help if i tested CR with a warm engine instead of an engine that was sitting off for 10 hrs :ohdamn:

ohh and who cares if someone says NOS instead of nitrous, same god damn thing. you know exactly what i was getting at
 
Compression ratio of pistons is different than cylinder compression. Piston CR will determine how much power you can make outside of boost and lower the number the better for boost as you have more margin for knock.

Cylinder compressions is how well the cylinder is sealing through a combination of piston to wall clearance, ring gap + sealing, valve sealing. Higher the number the better and 150 seems low for 4000 miles.

Your rings were broken in 3500 miles ago and your cylinder compression will not go up any more unless deposits are filling in gaps that shouldn't be there.

But yes, numbers on a cold engine will be lower so warmed up they should be around 170-180 which is good since parts are expanding :thumb:


You are still at the limits for the stock 1g rods though. You have some room to go but not much.
 
I had a rebuilt 6bolt motor with stock rods and weiseco 9:1 pistons. I had a 50trim on 33psi and a 75 wet shot for almost 2 years of racing every weekend. The car made 370hp 330tq on just boost on a mustang dyno. I ran a best of 11.1 @ 126 in the 1/4. the only problem I had in that time was a broken tranny. This was 6 years ago and I just talked to the guy that bought the motor from me 2 weeks ago and is still running!
 
Kinda like tissues and Kleenex? That is what happens when a brand name gets so large. Get over it.
 
I have a 6 bolt as well buddy :thumb: and the 150 compression is for how well it's sealing, not the CR of the pistons. Also, those people are really pushing their luck too. You can't go much higher than 450 on stock 1g rods.

Try 600 on stock 6-bolt bottom end.



Also higher CR pistons will give a higher reading during a compression test, and 150 is fine. OP nitrous away! :rocks:
 
i thought we discussed this?you will be fine but i would get Dsmlink before the nitrous kit your car isn't at 455 i can promise you that i would throw it on a dyno and check i would say by the trap speed you went at teh track and how it pulled mid 300s to possible high 300s remember my car probably didn't crack 400 and went 119mph.
 
i thought we discussed this?you will be fine but i would get Dsmlink before the nitrous kit your car isn't at 455 i can promise you that i would throw it on a dyno and check i would say by the trap speed you went at teh track and how it pulled mid 300s to possible high 300s remember my car probably didn't crack 400 and went 119mph.


yea when it was tuned on my other motor it was 455 wheel, got dyno sheet to prove it, this motor still has the same tune but with some different upgrades so power is gotta be lower
 
Run nitrous if you want, I don't understand why you don't try E85 or Meth/Alky first though.

id love to but i daily this car and there arent to much e85 sellers around her, plus i would have to get new injectors and a re-tune..i already have evrything for the NOS
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top