Rev Limiters

[Ash2005]

I am on the understanding that 7MGTE'S had Rev Limiters Installed when the engine was made in 86/87. Question if it does exist to what limit would it be set on a manual supra mark 3 turbo. I was going to get one installed, then someone pointed out it should already have one!

Im getting some major mods done in coming months and a few on way already, so i wanted to make sure i had one to take extra strain.

Ash

[Karma Supra]

Your car will have a rev limiter as stock.

raising it will yeild very little to none extra performance and possibly result in engine damage!!! As I am sure you have noiticed from driving it most of the engiens "go" is lower down in the rev range!

Out of interest, what are the "major mods?"

[zazzn]

unless your are turbo.

If you are turbo and have a large turbo charger you could probably get away with a 7500 RPM redline however, you'll need to get a standalone however, there was a guy in the US that was recrystaling the ECU to make it run slower to allow the higher rev limit.

[Karma Supra]

No.

AS he is talking about the 7M-GTE, we are talking about turbos.

Depending on what the "major mods" are I'd hold fast with the rev limiter. The car has one as stock, and like i said the power band is lower down the rev range.. Carrying on revving will yeild no performance gain, and probably just destroy your engine.

Now on running a larger turbo, forged pistons, uprated crank and rods and some head work being done, you might/will benefit from it!!! Just remember the 7M is a grunter not a screamer ;)

I have no idea what you are on about with making the ECU run slower, but it sounds very dubious to me!!! The stock ECUs are very good, and coupled with a piggy back fuel system (something like an Apexi SAFC-II), lex afm and 550s, you can get a lot of power!

[Martin F]

there was a guy in the US that was recrystaling the ECU to make it run slower to allow the higher rev limit.

←

Run slower ........... PMSL !

Did it idle at 8rpm instead of 800rpm as well !

[zazzn]

Sorry guys let me intoduce my self... I'm Zazzn form the supra froums...

www.supraforums.com

anyways if you want info on this read the posts on supramania

www.supramania.com

they where doing it for the MR2 guys.....

Basically the new crystal makes the ECU run as a lower MHZ slighly lower which make the ECU slower to react which is a good and bad thing.. good if you want to step over the stock revlimiter a little bad if you want it to adjust fuel curvs very quickly...

Anyways, form the tests that people where doing it had very good results....

BTW if you want to know what I have on my car I had a 63MM turbo and made 457 RWHP and 478 tq... www.7mpower.com look for eric wong.

As I was saying if you add a larger turbo the 7500 RPM powerband will be pretty good since your whole power band shifts to the later rpms since the bigger turbo takes longer to spool....

Any t04 series turbo's serge point is at about 4000 RPM give or take a few hundred RPM. You could still make positive boost before that point but it doesn't mean you have hit the serge point.

[Martin F]

Basically the new crystal makes the ECU run as a lower MHZ slighly lower which make the ECU slower to react which is a good and bad thing.. good if you want to step over the stock revlimiter a little bad if you want it to adjust fuel curvs very quickly...

←

I'm sorry but being an electronics engineer this is total <if my vocabulary was any smaller, it would be nearly as small as my genitals>. That statement is defenitely coming from somebody who knows nothing about how processors and circuits work.

Even if you just think about it logically, can you imagine how the processor is going to react to the crank and cam position signals when its running at say 8Mhz instead of 10MHz and how that will effect spark and injector timing.

As you're such a big member of the supra community why don't you try running your lowering of the clock speed idea past Reg Reimer i'm sure he will be over the moon to hear that all his work can be done in half the time by just changing a crystal

[zazzn]

I'm sorry but being an electronics engineer this is total <if my vocabulary was any smaller, it would be nearly as small as my genitals>. That statement is defenitely coming from somebody who knows nothing about how processors and circuits work.

Even if you just think about it logically, can you imagine how the processor is going to react to the crank and cam position signals when its running at say 8Mhz instead of 10MHz and how that will effect spark and injector timing.

As you're such a big member of the supra community why don't you try running your lowering of the clock speed idea past Reg Reimer i'm sure he will be over the moon to hear that all his work can be done in half the time by just changing a crystal 

←

You go there solider... Did I say I have one of these ecus? did I say I knew anything about them... I just said I heard of people claiming that they work. Like I said above GO READ before you pass judgement. Oh I forgot maybe it's easier to bash then to do some homework or well maybe it's even eaier to be ignorant.

[Karma Supra]

In all honesty, if so much mechanical engine work has been done, that the stock ECus rev limit really is THAT big an issue... -you should be thinking about an entire aftermarket management system :)

I have some plans for my spare engine... its nothing revolutionary, but I can assure you it will be no slouch... the Stock ECu is more then adequate with the lex/reimer mod, and an SAFC-II

As I am after drivability, and a decent power band over a totally unsuably peak bhp so I can wave the dyno slip about in willy size comparing matches...

After all... loads of lag is not much help around the twisties of the Nurburgring

[Martin F]

did I say I knew anything about them...

Errrr, didn't you post this...........

Basically the new crystal makes the ECU run as a lower MHZ slighly lower which make the ECU slower to react which is a good and bad thing.. good if you want to step over the stock revlimiter a little bad if you want it to adjust fuel curvs very quickly...

Or was it somebody else

Because to me, and everybody else reading that, it would indicate that you know how these things work and how changing the crystal effects things.

Oh I forgot maybe it's easier to bash then to do some homework

It should be than not then.........you may want to try doing some grammar homework. :D

My homework in electronics was done many years ago, i don't need to read a load of hearsay or BS to try and convince myself that all the theory is wrong.

or well maybe it's even eaier to be ignorant.

Really, how does it feel ?

At the end of the day i don't care if you want to believe BS or fact, but don't get so uptight when people who know fact laugh when you try to convince others of the same BS you believe in.

[zazzn]

Actually yes I did post it, and I said

"anyways if you want info on this read the posts on supramania

www.supramania.com"

But of course since your ashamed of your little weenie, you are going to be a keyboard warrior on the internet. Congrats you should feel like a camp that just won the Special Olympics.

"It should be than not then.........you may want to try doing some grammar homework. :D" Congratulations Mr. English teacher you just scored again

"My homework in electronics was done many years ago, i don't need to read a load of hearsay or BS to try and convince myself that all the theory is wrong."

Well obviously you have failed because all the information was on there regarding this mod. It works and it's been proven already.

"Really, how does it feel ?"

You tell me you've already proven your arrogance and ignorance by not thinking outside the box and saying "that’s impossible"

"At the end of the day i don't care if you want to believe BS or fact, but don't get so uptight when people who know fact laugh when you try to convince others of the same BS you believe in."

That’s fine tell it to the people that have already done it. :ffs: It's funny how it's the same any where you go there are just dumb asses that say "That's impossible" when they see it right before their eyes.

Anyways, back on topic as we where saying GE it's useless to do on stock cams, GTE it's usless to do unless you upgrade cams or get a bigger turbo.

Thanks,

[Karma Supra]

Someone with 8 posts giving it large against a respected member, who made a valid comment!!!

*uprated cams* don't tend to give much of a performance gain on a 7M, they just juggle the power band around and make the car less drivable. The whole point of that engine is the low down grunt.. if you want a screamer get a 1ZJ or a 1G-GTE mkiii!!! - I guess as you are into willy size comparing it is more important to you to have a bit of paper saying you have lots of HP, but drivablit yis not an issue, as no one can measure that anyway..

We have corners over here, so a wide powerband and drivability is better then beign able to boast what BHP it has and how ever meny thousand RPM... if we wanted to do that, we'd buy a honda!

Those subaru drivers are usless... top spec rally car and they still can't run over a 'tard

I still think the idea of slowing down the ECU is laughable!! yes, it will work, but how well?? It reminds me of all the "cheap" kmph -> mph conversions on the old soarer V8 actives... the speedo said the car was doing 100 mph, at 100 moh.. great problem solved!!! -the problem was the ECU thought it was doing 100 kmph and set the suspension, damping, progressive power steering and 4 wheel steering systems accordingly...

[Martin F]

Someone with 8 posts giving it large against a respected member, who made a valid comment!!!

Exactly and now he has resorted to throwing personal insults as he can't defend his own statements. To those of us who are a little bit more mature that kind of indicates a certain mentality.

Obviously there is not going to be any reasoned discussion with this loon, so i'm outta here.

[zazzn]

test

[zazzn]

You guys make me laugh, commenting on post count. Yeah because if you have lots of posts that says you know it all.

:hokus-pokus:

http://www.supraforums.com/forum/member.php?userid=8839

Happy 5800 posts? Does that make me elite or does the fact that I do ALL my own work, tuning and I still made decent numbers off my own 7mGTE.

You can talk all you want about going around the corners. In the end THEY ARE THE SAME CAR with same weight and same faults. 1JZ has a more smooth power band due to the stock twins add a large single on and you have the same problem as any single turbo car... LAG.. 1G is just a **** engine and I'm not going there, if you are bent on making 300 HP at 20 PSI stay with the 1G.

Anyways, that’s a whole different debate...

Back on topic, if you think cams make no power you are sadly mistaken cams depend on your setup. Yes hks 272's aren't going to help a stock ct26 very much but they do help. The gains that you get will be crossed out the negatives since #1 ct cant flow at high rpm and #2 you loose your low end spool because of the cam size. However, put a 70 MM turbo with 272's or 264's and guess what you've just added 50HP across the power band, and a faster spool.

http://www.supraforums.com/forum/showthrea...=installed+cams

Would you like to stick you're foot in your mouth now? :!Removed!:

BTW we are not talking about slowing the ECU down to a crawl say 5-10%, according to the guy, this reaction allows for like 500-1000RPM before rev limit.

So yes your timing, fuel maps will be off 5-10% but that’s why you have a slew of piggy backs anyways. Either that or you go to a standalone ECU.

As for the Lexus the progressive ps can easily be adjusted by adding more voltage or simply disconnect the Progressive PS anyways, the springs can be jumped to firm.... All these things are things you have to live with but they are your choice when you are doing mods... so don't say it's IMPOSSIBLE.

Again the people bashing because they simply don't know and are ignorant.

[GLI]

USDM (US domestic market) 87 turbo MK3's had a 6700rpm rev limiter

I'm not sure what the rev limit on your supra is but I imagine it would be the same.

Due to the fact that the stock CT-26 runs out of breath at around 5000 rpm, if you are running the stocker turbo raising the rev limit is not needed.

If you are running a larger turbo that doesn't spool as well as a stock one then it is in your best interest to raise the rev limit to get a larger powerband in boost. Naturally the limiting factor to this is the condition of your motor as well as the valvetrain.

The process, which zazzn is talking about is for the people that have all the supporting piggy backs to tune air/fuel ratio, but would like to take advantage of a higher rev limit. Now understand going to a stand alone here in North America is quite costly, as good tuner shops are few and far between. Transport costs, dyno costs and the price of the main unit stop us from this upgrade. For 300-400USD you can get a decent valvetrain upgrade that will enable you to take advantage of this modification.

The website is www.racerjake.com where the process is explained in detail.

As far as I know he has done 2 separate versions of this with one limiting the 7m at 7100 and another at 7500.

Please understand some of us will put piggybacks onto our cars so that we don't have to go full stand alone, I know AEM EMS is a nice plug and play system and works great, however buying the actual unit is a fraction of the associated costs IE: install, tuning, transportation

[Karma Supra]

You can talk all you want about going around the corners. In the end THEY ARE THE SAME CAR with same weight and same faults.

←

Wow, clearly you ARE the expert...

A 1Z and a 1G-GTE car have separate chassis numbers to a 7M-GTE powered car... Although the 1J car is muchly the same, the 1G car can be quite different!!! A 1G narrow body is a LOT lighter and much more nimble as a result!!! They are less nose heavy too!!! How do I know? Because I have a 1G car, I also have three 7M cars, and have had two 1JZ cars... I am about to build a 2JZ hybrid...

"As for the Lexus" sorting a 4WS V8 active is more complicated then that... before I "did" supras... I "did" soarers

RE post counts.. Having more posts does not mean anyone knows anything more... it’s more a courtesy thing (look it up), personal insults from newbies against long term forum members will never be appreciated! (Don't think I'm sticking up for a mate, he is a Mk4 driving infidel :P)

RE: your mature little pictures...

GLI your points are valid.. my point was that larger turbo means more lag, less drivability!!! Drivability is different to flooring it along huge straight roads!! I if you read my earlier post I was asking what "major" mods were... I don't rate 7M stock internals.. even at the standard rev limit!

[zazzn]

Yes I am no one ever said we where talking about a narrow body 1G twin.

If you look at the wide body 1G we are talking 40 KG of diffrence hardly something to be astonished by. If you are looking at the narrow body 1G then we are looking at 100 KG which is quite a bit of diffrence but the 100 more N*m of torque the 7m provies evens the playing ground. 7m has more potential then a 1G period I dont think anyone will argue that.

http://www.toyota-supra.info/models/1989_8/4611/

Twin Turbo 1G Narrow body 1460KG

http://www.toyota-supra.info/models/1989_8/4602/

MA70 1560KG

http://www.toyota-supra.info/models/1989_8/4613/

So i'm a newbie here doesn't mean I'm new to supras doesn't mean Martin started bashing on me and got everything he deserved. So now we argree that post counts don't matter. A second ago it was "Someone with 8 posts giving it large against a respected member, who made a valid comment!!!" you seem to indicate that post count matters.

Eaither way i'm not here to bash anyone about anything. I was here to let buddy know that there was some options for rasing rev limit. I'm sorry if I came off on the wrong foot.

I'd like to hope we all learned something here. What I don't know but that at least maybe there are things that people have done that maybe you or I never though of and guess what it may not be the best method but if it works it works.

The end.

[Karma Supra]

No one ever said we were talking abouta Ga-70, no... But we were talking about mkiii supras, :P you even mentioned the 1G in the same sentace!! there are some big power ones out there too!

I'm not sure how accurate that information is on the Ga-70!!!!! acording to that Aircon was not present, nor an option!!! Lies all lies! lol It does seem to be a car that people don't know a lot about!!

If I build my 2Jz hybrid, it will be a in a GA-70 narrow body Shell.. less weight and mk4 power.. I just need to do some sorting with the driveshafts and dif, the rest is all worked out!

Its either that or build a fast 1G just because I can...

[zazzn]

heh 1g fast to me is almost like a oxymoron. heh

I mean to be honest i'd rather have a 3sgte then a 1g.

[Karma Supra]

They like them in Aus there are some running 400 bhp...

HKS makea 2.4l stroker kit for them... but its silly expensive!!!!

in all honestly the cheapest way to makea fast mkiii is 2jz ;)

[zazzn]

I can only imagin.. HK$ is crazy money... yeah but they fully bulid these things for 400 bhp.

The 7m i had made 456 and all it had was ARP/Headgasket and a upgraded 63 mm turbo..engine was 100% stock

550 cc injectors, lexus afm but again 100% stock engine.. guy in the states here put 800 RWHP on stock block!

[Karma Supra]

Remember the BHP system is different the other side of the pond!!! Like Gallons!!!

Is that stock internal engine still going??? I have the lex afm, the 550s, the SAFC, the big turbo, (still on my coffee table lol) the bottom end has just had a full rebuild, but I am running a stock ish headgasket, stock head bolts, over torqued and re torqued three times after the gasket has settled to 75 pound feet... Heres to hoping it'll hold!!! (I have a "history" with 7ms lol)

The engine is perfect apart from the stem seals, which give me a puff on start up

I'm hoping to run it at a respectable 400 at the wheels.

As for the 800RWHP, is that one still going? how old is it??? By stock block surely you don;t mean stock internals too?

[zazzn]

Hey,

Sorry I ment to say 450 RWHP.

If I was you i'd get a metal HG and ARP studs... about 200 USD and the ability to know that you wont have to go though this head ache again. I'd reuse stock bolts but 3 times is pushin it ;)

Make sure you get the head and block machined if thats the case since you are rebuliding anyways... My machinest was able to get the head to .23 ra I believe .3 is the maximum allowence could be .25 though. (that was just though machining so no lapping required)

For the block we just used some terry cloth to clean it up and slapped the HG on with some "aircraft sealant" stuff that we found at the local car store (canadian tire)

The funny thing about this whole thing is I got that 7m for 400$ canadian! thats like 150 quid, and made all that power and had perfect compression.

The short if it is, i went to help my friend that had his car at a shop and didn't know supras well, the couldn't get it started I took out my cps to test with and when i went to put it back in to my car they didn't have a timing light and I jumped a tooth and had 30 degrees timing and melted 3 pistons on the way home. :censor:

The engine amazingly still worked well but was blowing oil out all over the place and had crazy blow by (dip stick shooting out oil in the intake comming form PCV) and tons of other stuff....

So I ditched the engine and I've been swaping to a 1jz. (quite rare in north america but getting less and less every day)

Anyways, as far as I know the 800 WHP guy is still running, he blew his intake manifold the same night after the dyno at the track when he has a nitrous backfire. The engine was fine though... Haven't heard much about him since though.

and when i mean stock block.. Yes stock internals, stock engine, stock cams, stock head. Manfiolds where aftermarket though.

One of my other runs 445 RWHP run was made on stock intercooler, stock exhaust manfiold with a adapter, and stock intake manifold. I only had upgraded intercooler pipeing because the old stuff just cracked and ripped apart at 20 psi of boost. (we get 94 octane at sunoco gas stations)

Here is the link, i can't find the better ones on it

http://www.supraforums.com/forum/showpost....86&postcount=50

Scroll up the orange car did 800WHP the white one 700.

Ornage one blew the intake manifold thats what the pictures are.

[Karma Supra]

Parts cost a *LOT* more here!!!! when I build my spare 7M I intend to impot prts from the US (eg, Je forged pistons, $800, here, £800...) I just need to work out how to not get stung by tax!!!

MHG is not really going to be an option on this engine as it is in situ, and not comming out!!! There is no point in using one unless I get the block surfece machined to make it *perfect* if mine is going to blow, I'll need to change it anyway, so I can look at doing it then!!! Should be fine as is on 15 or so PSI for now.... the other engine I am rebuilding already has an HKS 2mm headgasket, and it was holding fast at lots of boost, so hopefull it will come off and the block surface will be reusable (hopefully, not probably - I'm not sure about the headgastet, some say they are, I am more sceptical). I just hope I can get my forged internals, shot peened crank and rods, the headwork done and have it all together before the other engine goes bang....

the joys of Mkiiis