a while back, I've read and heard that if you boost more than 15~20 sec's, it's bad for your engine(or break somethin'?).. I don't know if that's with stock or built motor... is that true? Or is boosting low ok for more than 15~20 secs?

Sorry if this was question..

Thanks

 

i have never heard that...as long as you are tuned correctly shouldnt have any problems.

 

Actually, it is bad to stay in boost for more than 15-20 seconds at a time. If that's what you are looking to do then you have to tune specifically for that, which won't be max power. Boost for a long time builds alot of heat and i'm sure many people can tell you horror stories about melted pistons from highway racing!

 

boosted-hybrid told me not to boost for more than 15-20 seconds in fifth gear only,,, reason being is that he tuned my hondat 2b to be pretty good on gas mileage on the highway at about 75-80mph,, so its a bit lean up top, i know he tuned it that way but he didnt mention anything about boosting too long in lower gears,, alot of heat though, thats why you keep that in check with a egt gauge,,,

 

Well, cruising in 5th and wot in 5th are two totally different spots on the fuel map. The thing is that if you're in any other gear for 15 seconds at WOT then there's a real problem, your car is slow!! 5th gear is really the only one you could be in for that long.

 

actually also, i think that mainly turbo kits are used for drag racing, for the most part,,, ive never really heard anybody using turbo hondas for road racing specifically,,, i dont know,, 15-20 seconds of boost is a long time and alot of heat, i would imagine anywhere under 14 seconds is ok,,,, think of it as a quarter mile at a time,,, or whatever your tuned for,,,,,,,

 

That may be true..... highway racing and burnt engines.
I have NEVER heard of it myself. Any poorly tuned motor I have heard of
doesn't last long enough to worry about it.

But it shouldn't be that way.
If the engine is tuned properly, built for boost
and has the proper cooling (oil cooler, 80C thermo and better than stock rad)
you will be fine. Try road racing, 25-30 minutes at clip, WOT all the time
unless braking for corners (not much time).

I have run over 2 minutes on a stock D15 running ~9 psi @ WOT.
Running against an NA 2001 GSR: should have seen his face when I reeled
him in and walked him @ over 120.

Its all about proper tuning, 5 seconds of boost with poor tuning
will destroy an engine.

Not a bone-head question.... Why would your tuner tell you the car was 'done'
and the tell you how NOT to drive it? (odd advice imho)

Jeffrey Atwood

 

Thanks guys!! ^^

Let's just say my turbo starts spooling at 2000 rpm and I drive my car about an hour or more everyday on a free/highway, and it's not WOT but I have to keep the rpm around 4000 rpm(5~7psi) for me to keep it at a steady cruising speed... Would that be OK?

I hope what I said makes sense..

 

Just because you car is at 4000rpm doesn't mean your car is boosting. Boost is created when there is a load on the engine. On the highway at steady throttle, you car will not (should not be) creating enough load to create positive pressure in the manifold. My car drops to negative pressure as soon as the engine reaches the RPM relative to amount of throttle I give it. when I stepon the accelerator again..it then boosts again

 

ahh~ that explains it.. Thanks!

 

After reading this thread there are some questions I'd like to know and understand myself...

So basically boost only occurs when u floor ur car or ur at WOT right?

When ur at partial throttle then it steadies out and there are no boost at all...

In regards to correct engine & fuel management, I aiming towards to having this setup:

550 CC Injectors
Hondata 200b
Fluidyne radiator
Fmax intercooler
NX IC Spray

Will that be sufficient or more than enough to not be worried bout my motor failing on me?

By the way my intended boost will be only 6psi, with a stock JDM ITR Motor (C/R 11:1)

Thx... Still doing research... So thx for all the help and input...

 

You don't have to be at WOT to create boost either. You just have to be able create enough load for the engiine to produce enough exhaust pressure to spin the turbine. You can do this at partial throttle too. But, this all depends on the compressor size (smaller turbos spin with less load on the engine), compression (high compression engines produce more exhaust pressure), and of course throttle apature.

Compressor maps (although I don't know how to read them) will give you a good idea of what kind of turbo you want for your application and goals.

 

Seriously. I made 22 PSI at 1/4 throttle when my wastegate lines weren't hooked up right. Oops.

 

friend of mine...tuned jrsc gsr...long highway run 20-30 sec highway pulls full boost (a lot of them)=melted valve=bad.

 

We have canyon runs pretty much every weekend. I'm rarely at WOT for that long of time, but I am in boost for a good percentage of it. 15 minutes at a time usualy.

Haven't had any problems, temps & pressure gauges say things are alright.


I would assume 5th gear WOT for an extended period of time would put some serious wear on your engine. The heat would be waaayyyy extreme.

 

Thanks alot guys!!

 

Try boosting for 20 seconds. Even if you start at 0 youll be doing 120mph in the end.

But yeah, its probably bad on it.
gmoore

 

its bad even when using forged internals? forged piston will melt?

 

I went lapping at gingerman with my boosted car. I was boosting for more than 20 secs thats for sure(just not in the same gear) . the car is tuned really safely(ie , no power and is slow) so I was alright. I only started to over heat once due to my dp sitting against my rad

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by igotyofire &raquo;</TD></TR><TR><TD CLASS="quote">its bad even when using forged internals? forged piston will melt?</TD></TR></TABLE>

this is getting interesting..

 

yup...forged pistons are made of metal and metal does melt under high temps....forged pistons are a lot stronger than cast pistons, but they are still breakable!!

 

yes, but isn't the whole reason people switch to forged with forced induction setups due that it can deal with the heat better, not necessarily being stronger, becuase hondas cast iron pistons are very strong but i think forged is suppose to dessipate heat better, or withstand higher temperatures which most race motors see?

 

If youve ever owned a factory turbo car you might have noticed that some owners manuals tell you no towing with a turbo installed. Towing with a turbo could result in you running boost all the time. This can cause heat to build up in the combustion chamber and result in detonation. Is it 20 sec, 15 minutes or 2 days? Who knows?

 

somethin to think about... dunno if anyone else has mentioned this, but...

If you are at lower RPM's under higher engine load (i.e. wind + weight) then your pistons have the chance to pull a larger amount of air into the cylinders which in turn makes your turbo spool higher, and may cause you to run lean. Where as at high RPM's the air can only be pulled into the cylinders so fast and in so much amount, but by the time a stroke process is completed they are cooled down as opposed to lower RPMs.

That make any sense?

 

come on... someone... I didnt kill the dang thread with that one did I?
lol