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| question for the RB crowd | |
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| Topic Started: Nov 5 2009, 04:39 AM (484 Views) | |
| Deleted User | Nov 5 2009, 04:39 AM Post #1 |
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Deleted User
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a friend of mine has a Series II RB25 in his hatch and we have spent the past few days trying to determine the cause of his lack of power. and we cant figure it out. i pulled like 2.5 cars on him with my RB20 at 11psi. the 25 rolls out stock at 7psi with like 40 more hp. he is currently running ~10psi and is getting whooped on by ragged out v8 mustangs and poop. we swapped my MAF onto his car tonight and it pulled a little better but its still not pulling like a 25 should, he was wide open on slick pavement and never broke traction once (mind you hes on drift tires as well) we have checked the following: timing - stock setting spark - GNX coilpack conversion, so excellent spark fuel - its there. no misfires what so ever boost - consistent 9-10psi, creeps to 12 at WOT though vacuum at idle - 19" maf - only possible cause of problems, he said car performed better with my MAF clutch - grabbing hard any thoughts or insight as to what else we should check? i mean the car is smooth as hell on power, its not like my 20 where its like lag, lag, holy poop. the car pulls good from 2000rpm to redline. it just doesnt pull hard like it should. also, the car is a 100% bone stock motor with a 3" cat-back exhaust (no cat), FMIC, and aluminum radiator im out of ideas on this one. |
 
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| 240Smoke | Nov 5 2009, 05:05 AM Post #2 |
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you have a wideband hooked up? this would solve alot of questions. TPS or MAF are my 2 best guesses. |
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| Deleted User | Nov 5 2009, 05:07 AM Post #3 |
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unfortunately no. nobody has a wideband that we can borrow. but i did some google searching and it seems that this is a common problem with the 25. and the consensus says that its running too rich. one guy recommended advancing the timing 5 degrees and going from there with fuel adjustments. tps seems to be alright the car doesnt poop out randomly while driving |
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| 240Smoke | Nov 5 2009, 05:09 AM Post #4 |
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well it could be out of adjustment. yeah, I raped an RB25 S14 with my car once. I was running stock SR20 w/t25 @10lbs of boost.... |
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| turtle240 | Nov 5 2009, 05:14 AM Post #5 |
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TURTLE POLICE
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if the wideband doesnt solve it then mabye the injectors are clogged or check the compression (maybe hes getting blowby or something idk...) idk why boost peacks at 12psi when its set at 10psi thats sounds a little strange Edited by turtle240, Nov 5 2009, 05:15 AM.
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| 240Smoke | Nov 5 2009, 05:15 AM Post #6 |
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wideband wont fix anything, it just tells you the A/F ratio so you can figure out what the hell is happening. |
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| turtle240 | Nov 5 2009, 05:19 AM Post #7 |
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TURTLE POLICE
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^^^ i FAIL i was thinking of an SAFC oops wait would that work??? it shows your current A/F and you can adjust it Edited by turtle240, Nov 5 2009, 05:21 AM.
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| Deleted User | Nov 5 2009, 05:21 AM Post #8 |
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^+1 scott. and turtle boost creep comes from a sticking waste gaste. he doesnt know if it climbs higher hes always let out at 12. but if we can get a wideband that would make this SO much easier. i told him to get a timing light too and check the mechanical timing. his ignition timing is at stock setting thoguh. |
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| turtle240 | Nov 5 2009, 05:27 AM Post #9 |
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TURTLE POLICE
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ohhh i thought it said peaks not creeps it makes more sense now do the rb's have a timing sensor??? idk much about rb motors seeing as no one around me has one i just noticed it has a sensor on the timing cover |
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| Deleted User | Nov 5 2009, 05:28 AM Post #10 |
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yea thats the cam position sensor. thats how you adjust the ignition timing. |
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| 240Smoke | Nov 5 2009, 05:33 AM Post #11 |
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maybe RBs are just gay. |
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| turtle240 | Nov 5 2009, 05:35 AM Post #12 |
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TURTLE POLICE
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alright then how does the mechanical timing get messed up and someone didnt know about it unless it happened while the engine was out of the car |
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| Deleted User | Nov 5 2009, 05:38 AM Post #13 |
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no scott. rbs are not gay. haha and thats what im saying, i mean the mechanical timing obviously isnt more than a tooth off if its even off at all. because i believe 1 tooth is like 18 degrees, and seeing as how this is an interference motor if it was off too far the pistons would be having a face to face meeting with the valves. idk, we have to get the into a garage and just tear into it. |
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| turtle240 | Nov 5 2009, 05:40 AM Post #14 |
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TURTLE POLICE
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i think you would hear the pistons hitting the valves it would probably sound like piston slap |
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| Deleted User | Nov 5 2009, 05:42 AM Post #15 |
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thats what im saying. it could be off one tooth, but the car doesnt run THAT poopty. thats why i think the ignition timing could be off despite being at the stock marks. |
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