Safe range for the 4g63

[That_Guy]

What's going on guys? As you can tell I'm brand new to these site and was wondering if I could pull some info out of you guys. I have a little background when it comes to boosted cars. I owned a stock interal gsr hatch which made 343whp. Now the question I have is I hear alot of people throwing around psi of these cars but not the whp that they can withstand. So what I'm asking is what is the safe whp to run these motors at. I mean all engines have their limits and I know I'm going to get different numbers from everyone but what is roughly the safe limit before detonation. Example is I know when I ran my hatch at 343whp that I was only going to get maybe 2 years out of it which I did (still ran when i sold it just needed new rings) but if you wanted a quick honda and for it to last awhile like 4 years people recommend between 250-300whp. So what is the same limit to run these cars and make good power but still have it last awhile. Sorry for the redundant question.

Also this isn't a honda verse evo thread I was just asking a question and please do not give me "while I know this one guy that made 700whp on stock internals for 3 months before it blew" because thats not what i'm asking. Thanks guys Elliott.

[Larryboy]

Ive been building hondas for about 9 years and have always pushed myself on the most reliable best functioning turbo builds. its all in the way you build up to the turbo. And safe for what a stock 4G63 or a built 4G? I know rookhoe who is one of are Moderators was pushing 25 psi on his stock turbo and holding that amount of boost until close to redline. This is also with the stock 9 BOV and wastegate too. The 4G63 is one mean motor and can take some abuse that fosho


READ THIS ITS ALL YOU NEED >>> New To Your Evo??? Read Me


BASIC INFORMATION

What engine does my car have?
All currently produced American market evo's have the 2.0 liter 4g63 turbo motor.

How much boost is my car running stock?It depends on the year:
03-04s run 19.5psi at 3500rpm, which tapers to 16psi by 6500rpm
05-06s run 20.3psi at 3500rpm, which tapers to 17psi by 6500rpm

How big is my stock turbo?
Evo's come with different variations of the 16g turbocharger:
03-04 = 16g6 with a 9.8cm^2 turbine housing
05 = 16g6 with a 10.5cm^2 turbine housing
06 = 16g6 with a 10.5cm^2 turbine housing and larger compressor housing

What is stock fuel pressure?
43psi with the vacuun hose off and plugged.

How much does fuel pressure increase when I am boosting?
1:1 = 1psi per 1psi

What size are the stock fuel injectors?
560cc


What is the max boost on pump gas I can run?
The best answer to this is that there is no answer, and it's frankly not a good question, though it's often asked. Octane is definitely the main determining factor for how much boost you can run, but there are still many other factors, such as the mods you have, the turbo you have (differs between years)

How much boost can my stock blow off valve hold? When do I need to upgrade?
03-05 = Efficient to 13psi, but the turbo runs 19-20psi stock, so the BOV still works, but it's not optimum. It's a good idea to upgrade to a PROPER RECIRCULATING BOV (actually called a DV = diverter valve) as soon as you up the boost. It is considered a stage 1 mod on 03-05 USDM Evos
06 = Efficient to 24-25psi. No need to upgrade until running more than 25psi (requires race gas or alky injection) on the stock turbo or until you upgrade the turbo.

[That_Guy]

First off thank you larry for the response but it didn't really answer my question as to how much can you safely get out of these motors with stock internals. Also I keep hearing psi, Psi can differ from turbo to turbo. Meaning if you have a 35r and a 60 trim 10psi your going to produce way more power on the 35r. Larry when you say you can run 25 psi on the stock turbo and I"m taking it stock internals what are most people making to the wheels with this. Yes I know depending on the mods it may be different for other people. Anyways thanks for the help.

[That_Guy]

By the way I see I accidentally posted in the wrong forum can someone please move it to the newbie section.

[rookhoe]

While running 25psi, I was running Comp 264/272 cams and upgraded headstuds. Everything else internally was stock. One street tuning session I had put down about 395awhp with 0-1 counts of knock.

Generally while tuning Evos, we dont go by safe whp to run at. When tuning the 4g63 we look to see how much knock is produced during each pull and adjust air/fuel ratios and timing to correct it.

[SicLanEvo]

my evo was almost 400whp with 182k on it....zero issues. boosted 24-26psi daily. A good tune, solid parts, and good matience is key to achieve this.

[Larryboy]

Originally Posted by SicLanEvo

my evo was almost 400whp with 182k on it....zero issues. boosted 24-26psi daily. A good tune, solid parts, and good matience is key to achieve this.

(A good tune, solid parts, and good matience is key to achieve this.)

very well said

[That_Guy]

So is it safe to say that you could run 400whp on stock internals? Whats the first thing to go on these blocks that anyone is aware of. Example is for hondas around 450whp the sleeves are at risk to fail.

[SicLanEvo]

in most cases the evo's stock motor can handle 450-500whp. the older 4g63t's from the eclipe's could handle 450whp, the trans was the weak leak in those though.

[That_Guy]

Ok thanks sic that's what I was looking for. What is the breaking point for most of the evo 8 and 9 trannys? I know the mr tranny is weak and most swap the tranny for the 5 speed. Also besides the clutch being a weak point on most evos what else is next to go when increasing power?

[Larryboy]

Originally Posted by That_Guy

Ok thanks sic that's what I was looking for. What is the breaking point for most of the evo 8 and 9 trannys? I know the mr tranny is weak and most swap the tranny for the 5 speed. Also besides the clutch being a weak point on most evos what else is next to go when increasing power?

3rd gear lol

[SicLanEvo]

Honestly my car has 182k on it. and all the basic boltons with cams, and alky injection for safety.


This was all on origianl block, head, trans, turbo, diffs, and axles. I'm about 400whp daily driven over 100 miles a day.

weak point in my opinion is not the gear but the synchros.

[Devolution]

Pruven Performance had their stock internal 4g63 at a "reliable" 450whp. The key with reliable HP is most definitely what SiclanEvo said. It is all about maintenance and proper tuning. If something isn't right, fix it or change it.

My 91 Talon just turned 150k and is a 12.4 DD. I haven't had one problem with it.
Hope this helps you man!