what compression ratio are you running on your built block? your next step should be going to the non rev-up cog setup 32/28, or 34/28 seeing you are on a built block i would run some race fuel and run some crazy boost and see what you get!

 

how much boost did you see with the SC-trim? 369whp does not sound bad for 12psi on a dd.

 

Interested to hear your story. That seems a bit low to me for 12psi, even with lowered compression.

 

The numbers does seem kinda low i dynoed 378-380whp on the DD dyno @ 13psi with the stock motor, intresting to see what your tq numbers look like, 369whp isn't really bad for preliminary tuning.

 

what would DD #'s convert to on a dyno jet? a DD is load based right?

 

I had a 15.8% diff on the dynojet compared to the DD dyno which is prolly on the high side.
But i think your right the DD dyno might be a load base.

 

Ok so my built motor is 9.0:1 compression. and for this tune i was running a 2.87 serp pulley 34 tooth jackshaft pulley, and a 32 tooth charger pulley. When i ran the sc trim with the same setup i was seeing peek boost number of 10 and now with the Si i am seeing peek boost of 12.

The reason my number are a little low are for two reasons. one it was on a DD dyno. Second was becuase we didnt let the car cool down after tuning so im sure those numbers are alittle higher. but what im going to do is take it to a jet sometime in the near furture and see the REAL numbers!!!

The reason i didnt run the 28th yet is because this is my 3rd charger and i just wanted to get it running and also get some baseline numbers of the Si-Trim.

I will post up the graphs as soon as dave emails them to me i kinda forgot to get them cause i kinda hurried out of there!!!! College sucks in the morning!!

 

what type of fuel are you running? and how much timing are they pulling out at the top?

 

im only running 93 for right now just a pump tune and as far as timing im not sure!!

 

belive me on this. a 28 tooth s/c cog will wake that thing right up! you will not regreat it! i relized on my z the rev-up stock cog set up is what was holding it back. also for the revup guys i think the revup engine can take more boost due to there being more valve overlap with the cam configuration and phasing on both the intake and exhaust side. on this engine the cam overlap leads to more "so called boost leak out of the exhaust valve when the piston is comming back to T.D.C comprerssing the air fuel mixture" for lack of a better term. there is a word for this event but i cannot think of it right now. i really think the rev-up engine can have decent gains from having control over the cam phasing such as the haltech standalone ecu can provide. i was thinking of going with the F con but it does not have control over the cam phasing.i need to do more research but the haltech is looking good to me for my upgraded ecu options over my current U-TECH.

 

oooo i have a 28th cog and a 2.62 sitting at my house right now i just wanted to get a tune that wouldnt push the charger right away cause my car has been down since july and this is my THIRD CHARGER!!!!! so i just wanted it up and running! but in due time that 28th is DEF going on!!!!! with meth and some other goodies!!!! maybe a set of cams idk yet

 

28 tooth s/c cog YES!!!!!! 2.62 sep pulley NO!!!!!!! stay with the 2.87. i would not go any smaller than that you will have belt slip issues for sure and you will be over spinning the supercharger.

these are the combos i would suggest

34 j/s cog 28 s/c cog 2.87 serp pulley (for all out high boost).

34 j/s cog 28 s/c cog 3.12 serp pulley (probably the best combo to guard against belt slip and not over spinning the blower at 6600 rpm shift point)

32 j/s cog 28 s/c cog 2.87 serp pulley (pretty equal to the above rpm and output potential ) what i am running currently. the only reason i run the 2.87 serp pulley instead of the 34 j/s cog and 3.12 serp pulley combo is because if i shread a belt i can change it without removing the supercharger. on the revup installation the serp pulley comes very close to the supercharger volute. with the 3.12 pulley installed i cannot get the belt by the serp pulley, other wise i would run the 34 j/s cog 28 s/c cog 3.12 serp pulley combo.

 

SO would his lower compression pistons explain the lower psi he;s seeing compared to a car with pretty much the same breathing mods?

 

i would not be absolutely sure about that. but i would say he would have to make more boost to be at the same power level a higher compression VQ was making with the same mod's and supercharger setup. im sure sentry65 has a mathmatical equation to figure this out exactly. i know he stated before that for a given static compression ratio (say 10:1) reducing that compression ratio (to 9.0:1) you will expect to lose a said percentage of HP. that is why i am contemplating when having my built engine completed will i stay with 10.5:1 C/R pistons ( if i stay with the s/c and run strictly race fuel) or dropping down to 9.0:1 if i decide twin turbos are in my future.

 

Going from 10.3 to 1 to 8.5 to 1 compression isnt going to hurt you all that much and actually with give you more HP if you take advantage of it . You will be able to run more timing which will make up for the compression loss real quick
You guys with stock motors better take it easy or you will be building that motor .

 

Thank you for the input booger. if i do pop my engine it will just give me that excusse i needed to start that engine build a bit earlier that i expected.

 

i just ordered an alky kit, but better solution would be just buy a 3.12 pulley

 

if my z was my DD i would not try to push the stock short block this hard.

 

I'm gonna push my DE quite hard but I don't want to wreck the block this time. I am definitely gonna aim for 400whp on a SB but we will see. Built block after that (and recooping from my expensive project)

 

i will be dropping off my z at GTM tommorow around noon time for my tune on the si-trim setup. i am also having some custom exhaust work done so the z will be there for a week. will post my dyno results when it is done.