Supra Forums banner

1 - 20 of 22 Posts

·
Registered
Joined
·
1,214 Posts
Discussion Starter #1
I've noticed on all my dynos the power drops off quite abit after 6k. I realise some of it has to do with the bore/stroke/crank/rod ratios and mileage. Most 7mgte dynos have the same traits yet some don't.

But, what would it take for a flatter topend? Cams? If so what specs? EMS? Or cams+EMS?

The car has 130K OEM long block, T61, AFC, Profec SpecII, 3.5", 2.5" IC pipes, etc, and recently hit 420rwhp at 16-17psi.

Thanks.

-wt
 

·
Registered
Joined
·
1,877 Posts
IMO, it's the valvetrain. Stronger springs. That is of course if the turbo is capable of flowing enough for 6+k. That would be determined by the the hotside A/R and the turbine wheel for the most part.
 

·
Registered
Joined
·
2,555 Posts
yes valvetrain will help, cams as well.

a/r helps as well, your running a .58 a/r?


upgrade those parts, and it should definitely pull to redline
 

·
FIX-R upper
Joined
·
567 Posts
Shimless buckets anyone? havent used them but wont they take off alot of wieght so the spring does not have to work as hard to close the vale, also you wont have exra presure on the cams.. you do get i think about 20% engine friction off the cams. Tell me if im wrong because thats what my old High School teacher told us (he a SAE master tech.)
 

·
Registered
Joined
·
3,877 Posts
flow and valve float

Turbo efficency, flow of the IC, ducting, head, ect....

Most engines don't get max power at redline, so don't worry too much about it...
 

·
Premium Member
Joined
·
5,374 Posts
Upgraded valve train wont help to keep the power up, it just makes the engine to be able to rev higher without getting any valve float.

I have wondered this aswell, the power seems to drop at 5500rpm on 7M's.
 

·
Moderator, l337 M0d3r4t0r
Joined
·
12,222 Posts
one simple thing that you need to continue the power on the 7m is cams.

Just like my 1jz the stock cams are designed for the smaller turbos that come stock.
By adding cams I gained 136 WHP on top and made my 6500-7900 RPM band almost flat vs dropping 50-60 WHP.

I'm sure the stock vlave train of the 7m can take 7-7300 wiht out issues.
 

·
Registered
Joined
·
2,555 Posts
so from what i'm reading
cams, valve train, headwork
 

·
Registered
Joined
·
1,877 Posts
Yes, cams and probably porting. But you still have to have the turbo specs to pull through that RPM without choking off.
Hey Eric, did you gain 136WHP on cams alone? What cams?
In your opinion, what flattened you out between 6500-7900 as opposed to continuing the power slope?
 

·
Savage Member
Joined
·
1,033 Posts
I say cams make the biggest difference in power shift. I don't know jack about duration/lift and the only way to get cams for the 7M is well; expensive.

The HKS cams which most people can't even source anymore, are approx. $900. Someone has a set for sale in the forums here, and I would think custom 'one off' sets would come to somewhere near the same.

I wish, probably as many others that we had easy cam upgrades but unfortunately we don't and no one has stepped up to supply us or do r/d, since I don't think there is that big of a market for it anyways, atleast not to make money on.
 

·
Moderator, l337 M0d3r4t0r
Joined
·
12,222 Posts
Soon i'll have a line on Crower cams for 7m. Actually not CROWER Crower but his son.

Expect the prices to be 6xx. Anyways, yes it was just a addition of cams, nothing more nothing less. I dind't even get to tune the car after the cams, (wasn't really tuned before eaither) 0 adjustment on intake / exhaust cams gears. Here's the graph 18 psi vs 18 psi with the 272/264 cams for my 1jz.

http://webhome.idirect.com/~erwong/Temp/overlay2.jpg
 

·
Premium Member
Joined
·
5,374 Posts
ZaZZn said:
Soon i'll have a line on Crower cams for 7m. Actually not CROWER Crower but his son.

Expect the prices to be 6xx
More info pls!! :)

Different durations? What lift?

6xx each or for both?

When will these be available?
 

·
Super Moderator
Joined
·
10,153 Posts
You can eek out some more top end on the stock 7M head by playing with cam gears, but you'll lose some midrange torque.
 

·
Not so boring anymore
Joined
·
7,085 Posts
vtec... nuff said


no really... cams will hlep... vtec ones.. haha..
 

·
Registered
Joined
·
186 Posts
i use to run gude cams with oversized intake valves and tit valve springs and retainers. overall reliablity went to hell. made great power though. leave head stock and build bottom-end then get fuel and let turbo make you the power you want head work is expensive and hard to maintain(more rebuilds in your future)
 

·
Beats and Rhythm
Joined
·
2,732 Posts
Cams. You need more duration ( lift can be kept stock ). I had 272's made from Shneider this past week ( they should ship out with the new shims matched this week I do believe), comp cam valve springs, stock retainers, and Ferrera valve locks, and new treated valves. I sold my "big" T3/T4 turbo and smallish FMIC this week to save up some dough on a bigger/better turbo and intercooler.

I will have dynos and such this sommer.

I will be running my VPC/FCON as well. Shooting for low 400whp range with the turbo I will go with (full T4).

I really just want to see how much better the 272's will give the 7m top end power. As someone else stated, the power should shift dramatically to the top rpm range. I will have enough oil pressure too with the oil reloaction kit and such. Getting rid of the stock oil filter bracket system.

-Jonathan Mann
 

·
Premium Member
Joined
·
5,374 Posts
simann said:
Cams. You need more duration ( lift can be kept stock ). I had 272's made from Shneider this past week ( they should ship out with the new shims matched this week I do believe)
How much are the cams + shims?
 
1 - 20 of 22 Posts
Top