what breaks next? (raising redline)

[ZSPTurbo]

lets say I got the crower valve springs, valves, and retainers(http://www.crower.com/cat/import/mitsu/valvetrain.shtml http://www.crower.com/cgi-bin/detail.cgi?prod_id=84175)

what would I need to get next so that the engine could handle 8000 rpm safely?

p.s.
would it be worth it to get the titanium valve springs? I dont think so, they cost ALOT more.
also, if I get oversized valves, it would probably only be .5 mm... should I think about the .5mm oversized?

 

[20gst]

Ive raised my red line to 8500 with my 20g my powerband wants to work best between 4500-7500.
I have HKS 272/272 cams Upgraded springs retainers,stock valves and port size and I still run and flow pretty good I dont notice any problems.

 

[candela]

Rasing your redline wont do a damn thing unless you can match flow elsewhere. Youll need a turbo that can handle boost levels that high up, and a good flowing head (bigger cams). You dont even have a car yet dude...take i one step at a time here =) Tranny shifting, mishifting, floating valves, bigger cams, bigger turbo are all things you need to thin kabout before rasing the redline. The stock 7500rpm redline is prety sufficient for most applications


Ausitn

 

[ZSPTurbo]

Originally posted by candela
Rasing your redline wont do a damn thing unless you can match flow elsewhere. Youll need a turbo that can handle boost levels that high up, and a good flowing head (bigger cams). You dont even have a car yet dude...take i one step at a time here =) Tranny shifting, mishifting, floating valves, bigger cams, bigger turbo are all things you need to thin kabout before rasing the redline. The stock 7500rpm redline is prety sufficient for most applications


Ausitn

I already know that I need a bigger turbo, , and cams are sortof a given, but thanks for helping

sorry if I like to plan and know what Im doing in advance, and you dont.

Originally posted by 20gst
Ive raised my red line to 8500 with my 20g my powerband wants to work best between 4500-7500.
I have HKS 272/272 cams Upgraded springs retainers,stock valves and port size and I still run and flow pretty good I dont notice any problems.

thanks... how often do you take it up to 8500?

 

[larryd]

I run the crower springs/retainers and 1mm oversized SS valves and I had the Crower stage 2 cams. I revved the car to 8500 several times with no problems. My issue was the tranny, you cant really shift up there.

 

[ZSPTurbo]

Originally posted by larryd
I run the crower springs/retainers and 1mm oversized SS valves and I had the Crower stage 2 cams. I revved the car to 8500 several times with no problems. My issue was the tranny, you cant really shift up there.

thank god for team RIP engineering

Im just trying to gather info so I know weather its worth it to get the heavy duty/double synchro 3rd and 4th gears.... I might not, thought, might.

 

[focusedrage]

is it even posile to raise the redline on an auto? just wondeing

 

[candela]

I wasnt saying that your not planning...everyone does. You asked what you would need to handle 8000rpm safely and I told you, simply put.

 

[hostile]

I heard buschur even with huge turbos and what not shifts their race cars at like 7k rpm. I dont really see the point when you can have more power in the next gear of holding a gear longer.

The cool thing about it would be top speeds though. You could hit up into the 170 mark.

 

[red91tsiawd]

well doing the math, if ur car can still pull at 170, the redline would be right at 187.5 cuz at 3000rpm i'm going around 75mph so its around 40rpm per mph ... so u take ur rev limiter (7500) and / by 40 which = 187.5

is this correct or am i off by some?

mike

 

[hostile]

I dunno I know a guy with upgraded stuff maxed it out at 176 that wasn't stock.

I think stock ends in the 150's.

 

[Omega]

The only reason to run at such a high RPM is if you can't make any TQ down low (enter Honda S200)

What are you going to use the car for? If you are racing at high speeds all the time then yes I high RPM powerband is good. If you are a stop light racer like quite a few people here then you will never use the 8.5K redline to your advantage.

8.5K is pretty damn high. If you want to do it reliably and consistently, you need to have a VERY nice valvetrain. You will run into vavle float in a hurry at that speed. Light parts will be key in your equation, along with some rather stiff springs.

 

[ZSPTurbo]

Originally posted by Omega
The only reason to run at such a high RPM is if you can't make any TQ down low (enter Honda S200)

What are you going to use the car for? If you are racing at high speeds all the time then yes I high RPM powerband is good. If you are a stop light racer like quite a few people here then you will never use the 8.5K redline to your advantage.

8.5K is pretty damn high. If you want to do it reliably and consistently, you need to have a VERY nice valvetrain. You will run into vavle float in a hurry at that speed. Light parts will be key in your equation, along with some rather stiff springs.

ok, you sound like you REALLY know your ####. do you think the crower parts are sufficient? I have links to them above. I might not even go up to 8500 often, I just want to know that I will be able to. It seems from the other people in this thread that the crower parts, a decent sized turbo, and maby a port job would get me up there with room to spare.... do you think thats right?

 

[candela]

There are many people that use the stock valve train for 8000rpm shifting... I would trust crowers setups a little more as Ive used them before (they are said to hold 9k+) for shifting up that high. But as most will find, our trannies, regardless of condition, dont like to shift very well and usually grind like a mo fo' when shifting that high...

 

[Omega]

ZSPTurbo:

To be honest, my background is not in DSM's. But am familiar with engines and cars in general.

Crower do make some very nice parts, but certainly are not cheap.

What do you plan on using the car for?

It seems like a lot of money for parts that will not be used that often in their area of expertise. Put your money elsewhere. Port your head and work on all the little things.. you will be happier in the long run.