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New Rb25 dyno numbers.....595 rwhp


J Taylor

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Went back to the dyno tonight to do some more tuning and see what kinda power it makes on the nitrous. Laid down 445 rwhp on motor with a very conservative tune, through the th350. Hit it with the 50 shot and it made 515 rwhp at like 10.5:1 afr. Played around with different jets and ended up using a 125 hp nitrous jet with the 90hp fuel jet and it laid down 595 rwhp at 11.2:1 afr. On this pull I had nitrous leaking out from a fitting so I tightened it up and made another pull. at 6000 it was making 35 more hp than the last pull but it backfired due to an rpm error with the SDS. Did some damage to the intake manifold again (ballooned it but no cracks) and blew the IC pipe off. Had it been a full pull it should have laid down at least 630 or so to the tires. Tried to make a few more pulls on motor and kept having the same problem with it backfiring and throwing an rpm error code. Played around with the hall sensor location but couldn't fix it so I gotta talk to the guys at SDS tomorrow and figure out what to do exactly. Cant wait to see what 600+ rwhp feels like on some good tires. lol. Surely it'll be in the 9's now with some decent traction. Needless to say lag is not an issue on the gas.

 

Oh yeah, this was all on 93 octane.

 

Supposed to run a Hennesey twin turbo viper Friday night but I guess I'll have to put him off till I get this sorted out. It supposedly makes 700+ on pump gas and 1300 on race gas. Thankfully he said he'd be on pump gas and street tires...lol.

JT

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Guest 280ZForce

damn boy, good luck on getting the error figured out and racing that viper.

 

I highly recommend t-bolt clamps on all IC piping connections if you don't already have them.

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280zforce: It has t-bolt clamps everywhere.

 

s15: the pulls were made at 20psi.

 

cody: Good point.....I am definately goin to look into that this time around. Intakes are getting expensive....lol. This one looks pretty cool now.....custom rounded shape. I probably won't even get it redone for a while as long as it's holding.....for sure at least until I get the rpm error fixed.

 

JT

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That is totally awsome. 595rwhp is nothing to joke around with,

Especially comming from a 6 cylinder turbo charged with a spray of NOS.

 

We only put out last time at the dyno horsepower at the rear wheels was 566rwhp, on the 20% of NOS we are around 750rwhp. This is at 6500rpm at 16psi boost. When we go to 7500rpm we are at 600rwhp, have not tried it on NOS at that rpm level. 9's should not be a problem for you if you can plant it to the ground.

 

Congrats on the numbers.

 

 

John

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Jamie, The rpm error is most likely being set by a misfire. If you are using the supplied SDS coils, they are at the end of the road at that power level. You'll get a misfire and a nasty backfire when using nitrous. Starting at around 250hp/liter is where I've always found the end on any type of engine. You need to start using the MSD DIS. Never had any misfire troubles once the DIS is on line.

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Jamie, The rpm error is most likely being set by a misfire. If you are using the supplied SDS coils, they are at the end of the road at that power level. You'll get a misfire and a nasty backfire when using nitrous. Starting at around 250hp/liter is where I've always found the end on any type of engine. You need to start using the MSD DIS. Never had any misfire troubles once the DIS is on line.

 

Matt: What is involved in changing to the DIS? Could this also be the problem even on the motor at 450 hp?

 

JT

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Did the motor have a misfire at 450hp? If it did and it was the coils, it would happen at a progressively lower rpm as you increased cylinder pressure by boost or nitrous.

 

MSD sells spacer blocks for the GM style coils. These take the power and ground wires to the coils and intercept them for hook-up of the DIS.

 

In my experience with the SDS, misfire will always set an rpm error. This includes a lean misfire. The only reason I have ever had repeating misfire problems is due to inadequate coil output starting around 250hp/liter. Other things that could cause this is too much air gap between the mags and hall sensor, bad alignment of the mags and hall sensor, flimsy hall sensor mount, electronic noise from being right next to the alternator, etc. A customers TEC3 system once did this because the sensor was too close to the electric fan.

 

All the COP engines I do now use the MSD DIS and the stock coils. The SDS works well like this. It's something I came up with, tried, and used ever since. To date, I've run the stock Nissan coils in a waste fire format with the DIS up to 325whp per liter with no spark problems. Many have years as daily drivers wired like this with no coil failures.

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Yeah, it's doing it on motor as well....but not all the time. ANd it' s not just a misfire.....it's a pretty big backfire in the intake. I will definately look into the DIS.

As far as the hall sensor goes.....there is hardly any air gap and I am using the bracket I got from you. I realigned it while on the lift at the dyno and it didn't make it any better.

 

If you have any other ideas I'll definately listen.

 

JT

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