Max safe boost? [Merged 10-6]

[Turbolaser]

Is it safe to do the boost contol solenoid mod on a stock 1G?

 

[awdtsi601]

Originally posted by 98talonAWD
Tune the engine according to knock, timing, and EGT temps or get something even better... WIDEBAND!

9.0:1 compression with 27psi and a 75 shot. its been done and put down over 600whp. boost is not an issue till you make it an issue by being stupid with tuning. and with the higher compression you can run less boost and be hella faster than someone that has 8.5:1 on 25psi. you could run 20psi and be just as fast if not faster and be a lot safer than the other guy doing it. anything from 8.0:1- 9.0:1 is really really safe.

i just finishe dmy fully built motor with 9.0:1 wisecos, Eagle H beam rods, major head work and basically everything you can do to the 4G63 engine... i'd be happy running 26+psi.. and be fairly safe and reliable to boot.

il prove u wrong right there i drove around for a year on a bone stock gsr motor running a 57 trim 14psi everyday with a vafc and the car ran like a dream still dirives to this day same set up

 

[dsmturboawd]

57trim at 14psi, thats really sweet.

 

[crankbender]

Originally posted by 98talonAWD
Tune the engine according to knock, timing, and EGT temps or get something even better... WIDEBAND!

9.0:1 compression with 27psi and a 75 shot. its been done and put down over 600whp. boost is not an issue till you make it an issue by being stupid with tuning. and with the higher compression you can run less boost and be hella faster than someone that has 8.5:1 on 25psi. you could run 20psi and be just as fast if not faster and be a lot safer than the other guy doing it. anything from 8.0:1- 9.0:1 is really really safe.

i just finishe dmy fully built motor with 9.0:1 wisecos, Eagle H beam rods, major head work and basically everything you can do to the 4G63 engine... i'd be happy running 26+psi.. and be fairly safe and reliable to boot.

Actually if you can somehow spool the turbo and make the pressure lower compression ratios are better to a point. The gain in boost that you can run allows you to flow more air.

9:1 will not be faster @ 20psi than 8.5:1 @ 25 if they are tuned correctly.

The only advantage of a higher CR is a higher VE....but boost grows faster than VE falls in 90% of all cases. The reason race cars run as high a compression as they can is because it is VERY hard to get boost with a lower compression ratio.

il prove u wrong right there i drove around for a year on a bone stock gsr motor running a 57 trim 14psi everyday with a vafc and the car ran like a dream still dirives to this day same set up

Is there something wrong here or did you quote reply the wrong post. I don't understand what you are trying to prove wrong. He was saying higher CRs are possible. But to comment on your car. If you dropped the CR to say 7.8:1 you could up the boost to well past 30psi and make more power. However that power will be late in the RPMs.

 

[kpt4321]

Originally posted by 92awddsm
A stock honda has puny rods and floating cylinders and you can barely get over 8 psi without breaking parts. Without stand alone or zdyne gold ecu, you will never get over 6psi safely or reliably. Take this from someone who has had a turbochaged honda in the past.

You're dumb. My roommate has been running a turbo Integra for over a year at about 11 psi daily.

I tuned it, it runs great and pulls very hard.

 

[leet]

There's a whole lot of bullshit being flung around. None of us can tune YOUR car over the internet. Get a logger and start tweaking bit by bit. You'll get there eventually.

But there is just no way in Hell ANY of us can say "Oh your safe running X PSI on that setup." Because you may not be

Hence the reason I usually stay out of threads like this.

 

[candela]

Without stand alone or zdyne gold ecu, you will never get over 6psi safely or reliably. Take this from someone who has had a turbochaged honda in the past

:laugh:

Hence the reason I usually stay out of threads like this

me too, but now we are in them I have a suggestion... Now that you know a little bit better how easy a 4G63T can handle 13psi w/185+ psi in all cylinders... if thats all you want to run, or are very considerate of reliability, maybe you should consider sticking with stock compression. Stock 2G's will pump out more than 13psi.. aint no thang butta chikenwang

PS- 19psi, 56trim, 90+ degrees, 91 octane tuned on Dyno Dynamics

 

[Shane818]

the reason i went 9.1:1 is because i need my car back quickly. Dont get me wrong a lot of thought went into choosen the right pistons and i had 8.5:1 2g pistons but the machine shop had libility issues with machining the rods. Then very shop i called couldn't get the 8.5:1 i would have to wait until tomorrow to even order them. I have been borrowing my moms car and she just got diagnosed with cancer and she needs her car for doctor appointments. I probably will later in life go with 8.5:1 or 8.7:1. But for now this is the cards i was dealt. thanks for all the info and help. you guys are good help.

 

[crankbender]

Don't take anything we said the wrong way...9:1 is just fine with good gas

It just isn't a question we can answer for sure. Too many variables but you SHOULD be just fine.

 

[1LE]

Me -> 16g, stock SMIC, 9:1+, 550cc, 94 octane = 16psi no problem, 18psi "OK, but makes me nervous"

 

[Bastard1g]

This is scary, i have just read this thread and most of the replies here are either about
1. honda's which tuning wise, do not pertain to dsm's due to the differences in engines and engine management units.
2. people saying that if i can do it you can do it.
3. people not knowing what they are talking about.

The mods should make a sticky about different helpful post and links to books that car enthusiast can purchase to educate our members better.

I for one reccomend 2 books that i have read.

modern automotive technology- very good book, good for starters.

maximum boost by corky bell- another good book i have read a couple years back. very in depth with turbo's

as for the thread, i think he will be fine, i have went to 8:7:1 (stock) because i planned on running a big turbo on big boost with lil tuning issues being that i live in north florida where it sux.

 

[2GDSM95]

9:1 you should have no problems i am going to be runing a 1g block bord 20over with 9:1 piston's stock 1g rods the piston's are forged i should be able to pull 30pounds my friend 2g stock internal's boosts 25lbs
as long as you have a fmu should be ok

 

[Stanford]

Originally posted by Bastard1g
This is scary, i have just read this thread and most of the replies here are either about
1. honda's which tuning wise, do not pertain to dsm's due to the differences in engines and engine management units.
2. people saying that if i can do it you can do it.
3. people not knowing what they are talking about.


as for the thread, i think he will be fine, i have went to 8:7:1 (stock) because i planned on running a big turbo on big boost with lil tuning issues being that i live in north florida where it sux.

Are you sure you don't mean 7.8:1, that is stock for a first gen. You could have meant 8.5:1, that is stock for a second gen. You may be talking about an Evo piston setup, the 8.7:1 pistons Turbotrix sells. Either way please clarify, so others don't think DSM's have 8.7:1 compression stock. The Evo8 on the other hand does have 8.8:1 stock.

 

[kpt4321]

Originally posted by Bastard1g
1. honda's which tuning wise, do not pertain to dsm's due to the differences in engines and engine management units.

That's not true. You have load and engine speed based timing and fuel maps, and you have boost pressure, compression, A/F ratio, and knock. Tuning a Honda is just like tuning a higher compression DSM. Besides the fact that the internals are not as beefy and they can't make as much power, it pretty damned similar.

I've tuned enough Hondas to know this is true.

 

[Groomz]

Last time I checked, Honda's were internal combustion engines.

Stanford: You broke rule #3.

 

[Bastard1g]

Originally posted by Stanford
Are you sure you don't mean 7.8:1, that is stock for a first gen. You could have meant 8.5:1, that is stock for a second gen. You may be talking about an Evo piston setup, the 8.7:1 pistons Turbotrix sells. Either way please clarify, so others don't think DSM's have 8.7:1 compression stock. The Evo8 on the other hand does have 8.8:1 stock.

oh yea, sorry, im on a lil tiny lap top and i really dont pay attention as good. yea, 7:8:1.

 

[Bastard1g]

Originally posted by kpt4321
That's not true. You have load and engine speed based timing and fuel maps, and you have boost pressure, compression, A/F ratio, and knock. Tuning a Honda is just like tuning a higher compression DSM. Besides the fact that the internals are not as beefy and they can't make as much power, it pretty damned similar.

I've tuned enough Hondas to know this is true.

There are too many variables when saying honda's and mitsu's are the same.The valve entrance angles,injector types and spray patterns, combustion chamber shapes, intake manifold design and direction of tang( in case you want a better rod ratio) which rod ratio's and distance of stroke play a part in premature combustion. there are alot more than I listed, i just dont think its a good idea to generalize. Plus, from my past experience working for stan mizel and the rest of my sources, honda's are the shit and can make if not as much, more power than us.

 

[92redman]

Originally posted by 2GDSM95
9:1 you should have no problems i am going to be runing a 1g block bord 20over with 9:1 piston's stock 1g rods the piston's are forged i should be able to pull 30pounds my friend 2g stock internal's boosts 25lbs
as long as you have a fmu should be ok

Don't know how well that will work. Most aftermarket pistons and rods are designed as full floating. That means some clearance is built in the pistons and some is built in to the rods(wrist pin clearance). The stock piston/rod combo are press fit, which means there is clearance between the piston and wrist pin but the pins are interference fit with the rods so there are no oiling holes to the pins.

Back to the orignal post. I would agree with what I think most people are trying to say. You should be fine with 9:1, you just can't run higher boost with out high octane and good tuning. There are turboed N/T's on here runing stock level boost on there stock 9:1 pistons, which are considerably weaker than an aftermarket piston, with some success.

.02

 

[TT_NS]

Im rebuilding my TSI engine. And im putting 9:1 wisco pistons, eagle rods, arp studs, and a cometic head gasket. How much boost can i use safly withought hurting my engine.

 

[Lunch_Box]

Are you talking about during the breaking in of the new engine or after?

 

[L2RTSiAWD]

There are alot more varibles that will determine that then just the type of motor being built.

 

[TT_NS]

after the break in. Im just wondering how much it boost i could have before i blow a rod, piston, stud, or gasket. (parts listed in first post)

 

[kpt4321]

http://www.dsmtuners.com/forums/showthread.php?s=&threadid=96677

 

[anomalyinva]

7, as the answer to every unanswerable question is 7.

 

[vault415]

7? I thought the answer to everything was 42...

 

[Lunch_Box]

What turbo do you plan on running? Because 20 psi on 16g and 20 psi on a 60-1 is a big difference. We need to know more about your setup to give you any real help.