About spacers?

[Busabob]

 Let me run this by everyone to see if anyone has experience in it or any input.Ok I have a stage 1 rcc turbo on my gen1.  Say you make 240 hp on the dyno at 8 psi on a stock engine w/ stock 11.5-1 compression. Now if want to add a .080"  spacer you lower the comp ratio to about 8.5 (with stock pistons) which in turn you will loose about 20 hp off boost.Keeping the boost the same 8 psi you will loose that 20 hp on boost also (to about 220 hp give or take a few hp). What if you only used an .060" or even a .040" spacer instead and kept your compression to around 9.5 or 10-1 .Would anyone know the true comp. #'s. I assume the hp lose would not be so great maybe 10 hp lose? Then up the boost to about 10psi to get you back to or above the original #'s and still be safe with a lower compression ratio? Want to keep the boost in the 10 psi range for now.

[Chris Horoho]

.09 spacer drops you to about 9.5:1 comp not 8.5:1
and u lose about 10-15 HP
and a gen 1 should make from 250-260 on 8 pounds

[Busabob]

.09 spacer drops you to about 9.5:1 comp not 8.5:1
and u lose about 10-15 HP
and a gen 1 should make from 250-260 on 8 pounds

So you are saying that an .090" spacer will only drop 2 pnts of compression?? Is there a formula to figure out these ratios? I was always informed it would be 8.5:1 with an .080" spacer and loose about 20 hp (per RCC)

[Dan.J]

A .080 spacer and JE pistons will get u around 8.5 to 1 but stock pistons will be closer to 9.5 to 1. 240 at 8psi and stock compression is really low, eighther really rich or a boost leak or somthing. If I had it to do over again and was going to stay realitivly low boost (8#'s or less) I would leave the compression stock and get a good tune....should run real good. Drop the compression when you build the motor and put a better fueling setup on it and crank it up

[Busabob]

A .080 spacer and JE pistons will get u around 8.5 to 1 but stock pistons will be closer to 9.5 to 1. 240 at 8psi and stock compression is really low, eighther really rich or a boost leak or somthing. If I had it to do over again and was going to stay realitivly low boost (8#'s or less) I would leave the compression stock and get a good tune....should run real good. Drop the compression when you build the motor and put a better fueling setup on it and crank it up

Yes it was rich on the tune about 10.8-11.0 afr and had my ecu reflashed to remove 3 deg.timing which after the fact I was told to put it back in.

[Dan.J]

3 degrees of timing pulled shouldnt hurt to much really but yea really not needed. Hell put a 10# spring in it and 110 fuel with the stock compression, should run good. Keep a eye on that A/F ratio though

[BATTMAN]

you dont really need any timing pulled at that low of boost

[buzard]

don't touch it. throw the turbo on the bike and leave it alone. you tune it well and it will live forever. made 311 with mine and honda xx injectors. wasn't leaving motorheads shop until i saw 300  threw the dump on and tossed the pipe to the side. that did it. 


this whole spacer thing is over rated. for 240 hp you are wasting you time and money. keep the low end grunt and get the added turbo ass kick with the stock motor.

[Busabob]

don't touch it. throw the turbo on the bike and leave it alone. you tune it well and it will live forever. made 311 with mine and honda xx injectors. wasn't leaving motorheads shop until i saw 300  threw the dump on and tossed the pipe to the side. that did it. 


this whole spacer thing is over rated. for 240 hp you are wasting you time and money. keep the low end grunt and get the added turbo ass kick with the stock motor.

What is the max boost you can run with stock compressoin Gen1? With 93 octane and can you up it for 110 octane Sunoco race fuel? Would it not be safer to drop compression and raise boost a bit?

[buzard]

What is the max boost you can run with stock compressoin Gen1? With 93 octane and can you up it for 110 octane Sunoco race fuel? Would it not be safer to drop compression and raise boost a bit?

that is not easy to say. if you do 1 mile pulls with the bike, i would say 6lbs. you won't need alot. stage 1 fueling is really not right on every time you run. look at your fmu. it works, but it is not like a stage 2. at the track with good fuel 1/4 mile passes i have been 15lbs. you can keep the boost low with stock compression because the motor is a torque monster. this is me, but if i had a street bike and wasn't doing full throttle 180 mph backroad or ls runs, i would leave it stock.

[Busabob]

that is not easy to say. if you do 1 mile pulls with the bike, i would say 6lbs. you won't need alot. stage 1 fueling is really not right on every time you run. look at your fmu. it works, but it is not like a stage 2. at the track with good fuel 1/4 mile passes i have been 15lbs. you can keep the boost low with stock compression because the motor is a torque monster. this is me, but if i had a street bike and wasn't doing full throttle 180 mph backroad or ls runs, i would leave it stock.

Basically I just cruise on the street maybe a burst here and there to 4th gear to put some kid on a gixxer in his place. And just 1/4 mile drags on the weekend and some MIROCK events. So with that in mind what would you do to get the most at the track and still be streetable? Thanks

[buzard]

leave it unless you are going to start throwing boost at it in bigger numbers. once you go into it you might as well get the rods, pistons and a stage two upgrade. once you get bored with that you can get an ultra kit.

[megawatt]

Basically I just cruise on the street maybe a burst here and there to 4th gear to put some kid on a gixxer in his place. And just 1/4 mile drags on the weekend and some MIROCK events. So with that in mind what would you do to get the most at the track and still be streetable? Thanks

I like the info on this topic.  I am in the same type of environment that Busabob sees.

[Mr Brown]

I like the info on this topic.  I am in the same type of environment that Busabob sees.

Well hello Megawatt.......

[Bigrod330]

I like the info on this topic.  I am in the same type of environment that Busabob sees.

Me too.  But Im starting with stage-2 Ultra .  Going to run it on stock motor ( No spacer ) this year...then will see.

[megawatt]

Well hello Megawatt.......

Hello Mr Brown.   I like this site, I think I'll stay a while, learn some stuff and have a good time.

[Mr Brown]

Hello Mr Brown.   I like this site, I think I'll stay a while, learn some stuff and have a good time.

it's a cool place. Different than the .org, but still good. Lots of turbo stuff to check out.

[Ottocycle]

Hello all,
If I understand what you are saying if I run 7-8# boost and have a PC3 I should not need a spacer and I will not need to fool with the timing. I will be running an intercooler since I have the space. I have been reluctant to pull the trigger on my project for some time because the timing side of the equation intimidates me. I do not fully understand how timing adjustment works on modded Busa's. I know the PC3 that I have does not effect it.
I have a timing retard resistor on 5th gear. When I boost it should I can that? Does anybody know how much timing is added when a TRE resistior is in the system?
Thanks,

PS: Am I correct in understanding a TRE resistor only works in one gear?

[Chris Horoho]

no the tre eliminates the retardation of 1,2,3,4,6 gears and sets the timing to the same as 5th
5th is the only gear it doesnt mess with  

[Ottocycle]

Pinkey,

Thanks for the advice. So the TRE gives the first 4 gears the same timing curve as 5th gear. Is that right? 6th gear has its own timing curve which is different.