Safe raised rev limit value? stock 7m

[blackout_89t]

Hey...

So with the MSII redline can be set to whatever I want and I was just wondering what would be a safe limit.

Stock bottom end, stock head with MLS headgasket.

It won't be much higher than stock (what I had before was 6750rpm with early '89 ecu/7m), but even a couple hundred more rpm would help alot I would think.

I was thinking an even 7000rpm would be safe.
I know many people have gone over this, but with built internals...
This engine needs to last for this season and then gets stripped and built over the winter.

Quick mod list for reference:

Megasquirt II v3.0
EDIS-6 ignition
4 bar map sensor
Zeitronix ZT2 wideband O2 sensor
Denso 680cc injectors
Walbro 255lph pump
Custom -6an feed line/fittings
Earls inline fuel filter
Aeromotive Fuel Pressure Regulator
HKS 1.2mm MLS headgasket
SS tubular T4 exhaust manifold
Garrett GT40-82 50 trim comp. .81a/r exh.
K&N intake filter - 4" inlet X 9" long
Custom 4" intake pipe
HKS replica 50mm wastegate
Custom 3" downpipe
Custom 3" catback (no cat)
B&M oil cooler
B&M single oil filter relocation
24"X12"X3" core Megan Racing intercooler 3" in/out
Custom 2.5" intercooler piping - hot pipe
Custom 2.5" intercooler piping - cold pipe
Blitz DD blow off valve
Custom upper/lower radiator piping

Any input, either to go higher, lower, or to stay with stock would be appreciated. Thanks.

 

[X-man]

I'm on stock internals and I'm going to set mine for 7500 rpm on my AEM. Reg Riemer had experienced no problems turning 7000 to 7200 on a stock 7m with his Techtom upgrades.

 

[MKIIINA]

i think 7k is feasible on the stock head and block. there was a nice thread about the forces at work as engine speed increases and from that it was determined that 7000 was getting into the danger zone some. however as long as you arent letting the motor sit in 2nd doing 7k for an extended period im not too worried.

 

[spoolint78]

my locally buddy rev's his to 7500, although he's on a built bottom end, he is still on the stock head.

he's going with ted component cam's now

 

[lowbudgettarga]

treat it like i treat my '70 vw bus, rev it 'till it stops making power!!!!! There's no tach, but i assume in that thing it's about 4k at most. honestly though, I'm buying 87_7mgte's msII since he's moving on (not away from supras, his secrets) and i was planning on 7000, I think without cams th epower is just gonna keep falling after around 6k anyhow.

 

[Clifton]

I'm running MSII also. I set mine to 7500. Stock bottom end. Not that I will rev it that high very often but sometimes it will be nice to have the room in the lower gears. I know I have hit the limiter with the stock ecu in second way to many times.

Off topic, did you manage to get a good idle with 680's. I couldn't and put my 550's back in. I had the PW down to 1.4-1.5 ms but it moved around alot making the afr go from 12-15 when trying to achieve a mid 14:1.

 

[supra90turbo]

lowbudgettarga: 6,000rpm shouldn't be the limit of the stock cams. Anything other than a stock CT26 should pull hard to at least 6750.

What is the general consensus about megasquirt?

Clifton: love that 240z. honest to god, sickest old school japanese car ever.
To be complete, though, and I don't want to nitpick... please don't take it wrong.
to be absolutely perfect: black mesh wheels with chrome lip.

Still love the car, either way. Rather envious of what 533rwhp translates to in a 1,000lb lighter car...

 

[hottscennessey]

Kurt, I'm very interested in megasquirt. I have a friend who runs it on his turbo sunfire (yes he does), he has control over everything! That car is tuned and can seriously roll... for a sunfire. I'd love to go Megasquirt someday, but Its just not in the cards right now considering how well I'm doing with the Stock ECU and a MAFT.

Oh, and I know I want that Z so bad, I love the Supra, but there is no way she'd lose over 1k pounds. Without going crazy on the 7m we could all have 10 second cars.

 

[Reign_Maker]

This is a good topic... I'm using an AEM, and I think what I'm going to do is let my motor tell me where it should red line... I mean, watch the dyno numbers and see... If Im still pulling hard at 6500rpm, I'll push it up... But if I start falling off power at 7000rpm, there is no reason to push her to 7500...

Does that make sense?

 

[blackout_89t]

I'm running MSII also. I set mine to 7500. Stock bottom end. Not that I will rev it that high very often but sometimes it will be nice to have the room in the lower gears. I know I have hit the limiter with the stock ecu in second way to many times.

Off topic, did you manage to get a good idle with 680's. I couldn't and put my 550's back in. I had the PW down to 1.4-1.5 ms but it moved around alot making the afr go from 12-15 when trying to achieve a mid 14:1.

Hey,

Haven't ran the engine with the MS yes. Just finished building the board last week and starting the harness today.

After that I have to do some modifications to my IC piping and exhaust and hopefully that is all. I'll let you know how it turns out.

So the general consesus seems to be in the 7000-7500rpm for a safe zone? I think I will start with 7000. Dyno the car and see how well its making power up top and then adjust it accordingly.

Don't mind the primer.

 

[blackout_89t]

This is a good topic... I'm using an AEM, and I think what I'm going to do is let my motor tell me where it should red line... I mean, watch the dyno numbers and see... If Im still pulling hard at 6500rpm, I'll push it up... But if I start falling off power at 7000rpm, there is no reason to push her to 7500...

Does that make sense?

Took the words right outa my mouth as I was replying.