93 GSX 30 psi

[RED AWD GSX]

Hey everbody, I've been doing alot of research recently about what the max psi a stock block can handle, and every single thread always talks about how you should shoot for hp number and not psi number, and I know I know just get a set hp number and get there, but what I was really wanting to get out of this thread was mostly some second thoughts on what the more experienced members have to say about what I want to do. As of right now I am on 25 psi, and these are all of the supporting mods that I have to go with it, fp turbo manifold, tdo5h 20g, ets street fmic, 255 fuel pump, afpr, 750s, dsm chip, 2600 clutch, jacks 1.1 tranny and I have 0 counts of knock with the tune I did. When it was on 20 and when I put it on 25 I'm still pulling 0 counts of knock, so with what I have done so far do you guys think I could be able to pull that same thing off with 30 psi with my block being compltetly stock, stock head gasket and head bolts, and 0 counts of knock and not blow it up. Any input would be great for me at this point, thanks very much.

 

[gofer]

If you aren't pushing coolant or knocking running 25psi don't keep turning up the boost on those stock head bolts, make power by advancing timing at this point. By turning up the boost you're really working those head bolts and are just asking for trouble, when my head was lifting I wasn't knocking in the logs either. Just something to keep in mind...

 

[Devilman]

im assuming your on 93 oct with the injectors your running? correct?
like said above, anymore boost has bad news written on it for many reasons
i'd get at least some headstuds if i were you
then i'd probably start adding timing like said above

there no garantee with having a stock motor tho
even if your tune is really "safe" a stock headgasket will bite the dust at some point with age and extra power

 

[RED AWD GSX]

Thanks guys, maybe tomorrow I'll do some pulls with timing and when I put head studs and a metal head gasket in, then I'll turn it up and see if I can get to 500 and I'll post some videos and pics, thanks for the input.

 

[Devilman]

you wont ever hit 500 with a 20g sorry
but you can still go 10s with it
i did
very fast small turbo cars are a blast to drive

 

[bryzenga]

30 psi is deffinately asking for trouble, it can and has been done... but if I were you, I wouldn't want to mess with that kind of fire too much...

 

[Spoolin18]

30 psi is a no no on stock gaskets and headbolts, i don't think the stock bottom end could handle it for long. I would upgrade the headstuds to arp and a better head gasket. Lower and concentrate on more timing. I know its a completely different platform but I saw a shelby 500 pull 30 more hp on the same boost, afrs with 4 more degrees of timing. 25 psi is alot in my opinion. If your motor was bulit..i wouldn't sweat 25 psi. Evos run 19 psi stock but they have forged internals and my bro runs 25 psi with a few upgrades and a ecu flash.

 

[gofer]

I've been running 30psi on my stock 7-bolt bottom end for over a year now, the car has 103,000 miles on it and its my DD. To do it though, it requires a good tune and ARP head studs or else your going to kill your motor or blow the headgasket.

 

[2slow4utsi]

Stock block has gone 9's twice that I know of. I would suggest to get a better HG, valvetrain and ARP L19s though.

 

[gofer]

Stock block has gone 9's twice that I know of. I would suggest to get a better HG, valvetrain and ARP L19s though.

These are unnecessary and overkill to your build, the standard ARP headstuds will work just fine for 30psi. As far as upgrading headgaskets goes, the Mitsu composite headgasket is about the only thing you should run if you only resurface the head.

I'm not sure how fast the stock block has gone but I know that a 500whp stock block 4g63 has been done many, many times.

 

[turbo tim1]

30 psi from one turbo to the next is completely different.
When you are measuring boost pressure that measurement is what is not getting into the engine that is why your gauge measures pressure.

What the real question should be, is how much volume of air is getting into the engine. The more volume of air the higher the cylinder pressure, which requires upgraded head bolts and possibly upgraded head gasket, depending on your over all set up.

I am not familiar with the capabilities of a 20g but I am willing to bet it will be out of its efficiency range at that level of boost, creating hot air, so I would agree 30 psi on that turbo is probly not a good idea.

 

[RED AWD GSX]

Well let me ask you guys this. Do any of you think that I could be able to even turn my td05h 20g up to 30 and still be within its efficiency range, because right now with how I have everything, if I do a couple of pulls through a few gears each time and then I pull over to let the car cool off (mostly just a habbit of mine) I can touch the cold side of my fmic piping and the intake manifold, and they are both cool to the touch, wouldn't that not be a bad thing, as far as my turbo generating heat because of being out of its efficiency range, just asking thanks.

 

[turbo tim1]

Well let me ask you guys this. Do any of you think that I could be able to even turn my td05h 20g up to 30 and still be within its efficiency range, because right now with how I have everything, if I do a couple of pulls through a few gears each time and then I pull over to let the car cool off (mostly just a habbit of mine) I can touch the cold side of my fmic piping and the intake manifold, and they are both cool to the touch, wouldn't that not be a bad thing, as far as my turbo generating heat because of being out of its efficiency range, just asking thanks.

Like I said I am not familiar with a 20g turbo, but you can figure out if you are in the efficiency range of the turbo if you have it's compressor map.

TurboByGarrett.com - Turbo Tech103

I have done these calculations to figure out the best turbo for my performance goals, this is how you get the most out of what you want. Some people just bolt on a big turbo and hope for the best and some times they get lucky. But if you want perfection this is what has to be done. I am sure you could find out what you want to know about the question you have just by searching this forum because chances are some has done it.

happy hunting.

 

[DSMTyson]

So would that mean having a Holset H1C 8-blade at 25psi with arp head studs and a good tune be safe for my stock bottom end?

Thats the future setup i'll be on in the next month or 2.

 

[turbo tim1]

So would that mean having a Holset H1C 8-blade at 25psi with arp head studs and a good tune be safe for my stock bottom end?

Thats the future setup i'll be on in the next month or 2.

I am not familiar with Holset H1C 8-blade.
25 psi of boost on a 16g and 25 psi of boost on gt42r will give you massively different results in hp.

The real question should be how much power can a stock bottom end hold. I have personally been over 400 whp on stock internals and never had a problem I don't know where it will let go at because I never took it to the limit on stock internals to find out. I have read about a guy that made as much as 580 on stock bottom end in a magazine a few years ago, whether or not this is true I don't know.

If you really want to know find the compressor map for your turbo and do the calculations with the formula from garrets web site.

 

[BoostedBeaver]

Turbo Tim1 is correct. You should listen to what he has to say. A turbo can make as much boost(PSI) as the compressor and turbine wheel can make in a given housing.This does not mean more is better. For instant, lets take a 16 at 14lbs and a HX35 at 14lbs. If you take a look at the Compressor map for both turbos you will see that the Holset is not even starting to flow (Lb/Min) much air as the 16g will be flowing more at this low PSI. Also if you take a t25 and push 25lbs it will be scorching hot. I know that these are extremes but it is just to show you that you must find a turbo that meets your needs. To the OP you can very well do the 500 on the stock block. With a block that is in deceent shape, ARP's, and headgasket it is atainable. You must have a good tune and make sure you monitor all critical gauges as much as possible. Good luck.

 

[DSMTyson]

I am not familiar with Holset H1C 8-blade.
25 psi of boost on a 16g and 25 psi of boost on gt42r will give you massively different results in hp.
The real question should be how much power can a stock bottom end hold. I have personally been over 400 whp on stock internals and never had a problem I don't know where it will let go at because I never took it to the limit on stock internals to find out. I have read about a guy that made as much as 580 on stock bottom end in a magazine a few years ago, whether or not this is true I don't know.

If you really want to know find the compressor map for your turbo and do the calculations with the formula from garrets web site.

I realize a 42R and a 16G are not going to give me the same power output and drivability on a certain boost level due to spool up and the fact that the 42R flows WAYYYY more air on higher boost levels. I'm not an idiot...

I'll take a look at the formula on garretts website. Thanks.

Turbo Tim1 is correct. You should listen to what he has to say. A turbo can make as much boost(PSI) as the compressor and turbine wheel can make in a given housing.This does not mean more is better. For instant, lets take a 16 at 14lbs and a HX35 at 14lbs. If you take a look at the Compressor map for both turbos you will see that the Holset is not even starting to flow (Lb/Min) much air as the 16g will be flowing more at this low PSI. Also if you take a t25 and push 25lbs it will be scorching hot. I know that these are extremes but it is just to show you that you must find a turbo that meets your needs. To the OP you can very well do the 500 on the stock block. With a block that is in deceent shape, ARP's, and headgasket it is atainable. You must have a good tune and make sure you monitor all critical gauges as much as possible. Good luck.

The H1C is the older version of the HX35. The 8-blade is the most efficient of the H1C's to my knowledge . The HX35 is a little more efficient and flows a couple more lbs/min.

so maybe i should rephrase, since the 2 are so similar. Is an HX35 on 25psi a good idea(safe) on a stock block with a good tune or do you think i will be regreting it in a couple months due to bottom end failure.

 

[jed344]

you have a 6 bolt. They are pritty strong motors. I have a buddy that has been running 23psi on his evo 3 16g stock 7 bolt dsm cept for studs and gasket for over 2 years without a issue.