I've got a 95 Integra RS ( http://www.we-todd-did-racing....x.jpg ) I'm using for track use, and I'm putting it up on the dyno this week to have the ECU tuned and see what my SMSP header does ( https://honda-tech.com/zerothread?id=1303887 ). Just wondering what a safe rev limit is?

I wont be adding any cams, nos, headwork, turbo, vtec etc at all... just stock motor. I will probably build a "fresh" head over the winter but that shouldnt change anything at all. Keep in mind it will be run 30-40 min at a time WOT in summer heat - reliability is more important, but I dont think I will see significant power gains over 6500 rpm anyways.

THanks all.....

 

I believe once it's on the dyno, you'll almost certainly note that the power begins to fall off before the factory redline is reached. If that's the case, the stock redline (6800?) should suffice, with a fuel cut perhaps 100 RPM higher.

 

Stock fuel cut is 7200.

I'll have a 4.9 final drive in the car as well - which means more time in 5th gear, and the 4-5 shift drop is pretty big. I'd rather keep the revs up in 4th a little longer, but I want to keep it in a safe range.

 

From my experience, you should peak between 6300- 6500 rpms

 

I was goign to say 6500 will be about when you hit peak.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybrid_vtec &raquo;</TD></TR><TR><TD CLASS="quote">From my experience, you should peak between 6300- 6500 rpms</TD></TR></TABLE>

That wasnt the question at all.......

 

There's not much going on beyond 7,000rpm in those motors, I would set the rev lmit at 7,200ish and shift at around 7,000rpm.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drdisco69 &raquo;</TD></TR><TR><TD CLASS="quote">There's not much going on beyond 7,000rpm in those motors, I would set the rev lmit at 7,200ish and shift at around 7,000rpm.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">I'll have a 4.9 final drive in the car as well - which means more time in 5th gear, and the 4-5 shift drop is pretty big. I'd rather keep the revs up in 4th a little longer, but I want to keep it in a safe range.</TD></TR></TABLE>

Try driving a B18B w/ stock tranny on track and you'll understand.

With the motor stock, it would really die out above 6400. With this header, it falls off, but not flat on its face like the stock manifold and still pulls hard to the fuel cut. I would rather hold out in 4th gear a little longer, because when you do hit 5th shifting at 7000 it really falls flat.

http://iammike.org/in_car_vids...t.wmv - right click, save as - I hit 5th down the front straight.... that was shifting at ~7100.

Now.....

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">Just wondering what a safe rev limit is? </TD></TR></TABLE>

 

Ok, I feel your pain now. When I had my LS, it was going through a GS-R trans.

I would just see how high people are taking them without much failure. Remember that one drag race isn't the same as 20 minutes on VIR, you're up at those revs for a lot longer. I would venture to say up to around 7500 may be ok, but I never messed with my LS, I just accepted that it was slow. See what people more LS-saavy than me have to say though. I'm just this guy, you know?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drdisco69 &raquo;</TD></TR><TR><TD CLASS="quote">Ok, I feel your pain now. When I had my LS, it was going through a GS-R trans.

I would just see how high people are taking them without much failure. Remember that one drag race isn't the same as 20 minutes on VIR, you're up at those revs for a lot longer. I would venture to say up to around 7500 may be ok, but I never messed with my LS, I just accepted that it was slow. See what people more LS-saavy than me have to say though. I'm just this guy, you know? </TD></TR></TABLE>

Exactly!! When you are in 4th and 5th gear going to 7K+, you are holding those rpms for a while rather than like a drag race which is only a few seconds. SO the longer you stay in the high rpm range the more likely you are to run into problem!(Spin a bearing, break a rod bolt, etc.) Seriously I would not go over 7K for long periods of time, especially in 5th. 4th gear I say you can stretch to 7500, but eventually I recommend to change the rod bolts to ARP's and replace the bearings(and replace them after every season, or as needed due to wear patterns).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybrid_vtec &raquo;</TD></TR><TR><TD CLASS="quote">Seriously I would not go over 7K for long periods of time, especially in 5th. 4th gear I say you can stretch to 7500, but eventually I recommend to change the rod bolts to ARP's and replace the bearings(and replace them after every season, or as needed due to wear patterns).

</TD></TR></TABLE>

I dont think I'll have near enough power to hit 7500 in 5th gear Maybe if i installed a 5.9 final drive

3rd/4th I think could benefit from a few more revs though - I am hoping this bottom end holds together through next year as well, the motor runs real strong now. I'll probably have my spare head prepped (valve job, slight mill, port match, etc) over the winter but thats it. I guess I could do ARP rod bolts as well, not that hard of a job. I was thinking a 7600 rpm fuel cut would be good, but who knows.

I know there's a lot of conjecture and assumptions floating around with the rev limit on these motors - I was hoping someone would have some experience with this. I know a guy running honda challenge that used a b18a for 3 years and ran it to 8000 without any problems, but he did have the motor out at the end of each seasion. He said anything over 8000 and you're really asking for trouble and need to tear it down every other race.

 

TO make use of 7600 rpms, you will need some cams! I rev to 8K all the time but I peak at 7600. Like I said after this season tear down the block and replace the bearings, rod bolts and piston rings. Then I would tear it down again in the middle of next season to see how they are holding up, and then decide if you need to replace them after "X" number of races. Also you will benefit from a set of B16 pistons. They are OEM so , the Honda Challenge will allow it. Another thing you may want to look into is an OBD-II oil pump since they are better than the OBD-I LS oil pumps, and also why not make a trap-door system for your oilpan!(Keeps oilpump from starving around turns, while allowing oil to still drain back into the pan just as fast as it normally would)

Just some thoughts. Tell me what you think.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybrid_vtec &raquo;</TD></TR><TR><TD CLASS="quote">TO make use of 7600 rpms, you will need some cams! </TD></TR></TABLE>

Well i'm more looking to prolong and slightly alleviate the bog at the 4-5th shift than anything else. It will make more power @ 7500 in 4th than 5000 in 5th.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Also you will benefit from a set of B16 pistons. They are OEM so , the Honda Challenge will allow it.</TD></TR></TABLE>

Not for H4 - only H1.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote"> Another thing you may want to look into is an OBD-II oil pump since they are better than the OBD-I LS oil pumps</TD></TR></TABLE>

What is different?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">and also why not make a trap-door system for your oilpan!(Keeps oilpump from starving around turns, while allowing oil to still drain back into the pan just as fast as it normally would)</TD></TR></TABLE>

I had one on my ITR, and it seemed to do the job.... I also crew for a team running scca enduros with a 95 Integra RS, and we have a mechanical oil pressure gauge hooked up. With the oil level full, we've never seen a drop in pressure in turns. I will probably add some simple baffles to my pan (i've got a spare) on principle, but its not a priority at all.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">
Not for H4 - only H1.</TD></TR></TABLE>

Oh, ok. My bad!


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">
What is different?</TD></TR></TABLE>

Not sure to be exact, but I believe the it is supposed to flow more oil and be a better built pump since many of the old pump are known for the pump gear shattering. This is what I have been told over the years and I opted out for an OBD-II pump. I can tell you that the part numbers are different.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">
I had one on my ITR, and it seemed to do the job.... I also crew for a team running scca enduros with a 95 Integra RS, and we have a mechanical oil pressure gauge hooked up. With the oil level full, we've never seen a drop in pressure in turns. I will probably add some simple baffles to my pan (i've got a spare) on principle, but its not a priority at all.</TD></TR></TABLE>

Been told the same as well but there are many ppl that run it too. I just did it as an extra precaution.

 

RJ,

The rod bolts are the weak point in the rotating assembly. Regardless of where power falls off, you would be safe to stay under 7500rpms. I have very little knowledge of the the HC rulebook but if they allow the replacement of the rod bolts with ARP units it would be a good idea if you want to rely on this motor for a while.

The OBD2 oil pumps have slightly tighter tolerances on the pump gear, and are the same for all B-series models. Whereas the OBD1 pumps differed between VTEC and non-VTEC models. The OBD2 pumps also have mountings for the crank fluctuation sensor, and require an OBD2 lower timing belt cover to fit onto an OBD1 block. If you recall, earlier B-seriese engines had problems with higher RPM resonance on the oil pump gear, hence the creation of the ProDrive and TODA oil pump gears, supposedly the OBD2 pumps fixed this occurance. Although you wont be running into any situations where the oil pump could potentially fail due to RPM's, as they motors those gears were designed for operate above 9000 rpms. From what I've seen on oil pressure gauges, both OBD1 and OBD2 pumps have the same pressure at idle and WOT, so the idea that they flow more is more of a rumor I believe.

Good luck,
Marshall

 

Would you recommend dropping the pan and replacing the rod bolts with the block in the car? Is there enough clearance in there to measure bolt stretch?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">Would you recommend dropping the pan and replacing the rod bolts with the block in the car? Is there enough clearance in there to measure bolt stretch?</TD></TR></TABLE>

b-series rod bolts = press fit

they will need to be pressed in and the large end of the rod will need to be resized to assure the bore is perfectly round. I have heard of people doing it in the car, but it's not something you would want to take your chances on.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 743power &raquo;</TD></TR><TR><TD CLASS="quote">

b-series rod bolts = press fit

they will need to be pressed in and the large end of the rod will need to be resized to assure the bore is perfectly round. I have heard of people doing it in the car, but it's not something you would want to take your chances on.</TD></TR></TABLE>


Exactly!

 

i set my rev limit to 7600 rpm on my ls turbo and it lasted 2 months or so of 10 lbs of rev limit crunching abuse, i did spin a rod bearing eventually though

 

i would be more worried about whats going on with the head as oppsed to teh bottem end.

I dont know much about the ls heads but r the vavlesprings ok at that kinda rpms?

 

Just an update - I have been spinning the thing to 7700 rpm on track for several events now with some mixed results.

With the header and ECU tune the car makes great power up top - no question on the performance, and revving it to the limiter in 4th gear makes using 5th on track a bit faster.

The engine hasnt thrown a rod through the block, however the valve adjustment nuts like to loosen and back out. I pulled in off one session, with a loud valve tick and the nut had flown off and dropped into an oil drain hole. Its actually still there, but hasnt hurt anything I have found others get loose, so they require constant attention.

I am not sure if it is related, but the engine is getting very tired - compression is down, a lot of oil blow-by and its down on power. Probably not due to the revs, but I will be rebuilding it next month and hopefully it will be solid after that

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">Just an update - I have been spinning the thing to 7700 rpm on track for several events now with some mixed results.

With the header and ECU tune the car makes great power up top - no question on the performance, and revving it to the limiter in 4th gear makes using 5th on track a bit faster.

The engine hasnt thrown a rod through the block, however the valve adjustment nuts like to loosen and back out. I pulled in off one session, with a loud valve tick and the nut had flown off and dropped into an oil drain hole. Its actually still there, but hasnt hurt anything I have found others get loose, so they require constant attention.

I am not sure if it is related, but the engine is getting very tired - compression is down, a lot of oil blow-by and its down on power. Probably not due to the revs, but I will be rebuilding it next month and hopefully it will be solid after that </TD></TR></TABLE>

How is it now, after the weekend?

Was this an old street motor, or has it been rebuilt ever? Are you going to build it to the limits (compression and bore, port match) or just a normal rebuild?

G'luck, hope you don't have much downtime. I'm already pissed at my car and I haven't tracked it yet this year (leaking radiator, bad passenger front wheel bearing.)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris F &raquo;</TD></TR><TR><TD CLASS="quote">How is it now, after the weekend? </TD></TR></TABLE>

Seemed better this weekend - I put in an Endyn breather kit, so that seemed to keep the blow by and oil use down.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris F &raquo;</TD></TR><TR><TD CLASS="quote">Was this an old street motor, or has it been rebuilt ever? Are you going to build it to the limits (compression and bore, port match) or just a normal rebuild?</TD></TR></TABLE>

Original engine as far as i can tell - I'll build it within my budget, which will get me 90-95% to a "to the limit" build as far as dyno #'s. .020" overbore, port match and assemble it myself.