992gnt Posted October 22, 2014 Report Share Posted October 22, 2014 So, I have no idea where to put this, so here it is. I've been reading threads on performance builds using the G54b. It's kind of depressing. But something is not adding up in my mind so, since I'm new to this platform, I'd figure I should start by asking some questions. It seems unfathomable to me that these cars have such a hard time getting above 400 whp. Below is a hypothetical build, what am I missing here? This should do 400 EASY at around 25 psi. Right?? If not, why not? G54bstock crank and rods9.5:1 pistonsBSElightly ported head, jet valves removed, aftermarket camSMIM or equivalent, running EFI, ~950cc injectors (guessing, haven't done the math yet)1g engine wiring harness, DSMlink with CAS in place of the distributortubular exhaust manifoldMHI 20g3" turbo back exhaust I'm not trying to build a drag car here, but 350 hp would make this the slowest car I own! I'm not trying to infer anything, or show any disrespect to those that have "been there and done that", so please enlighten me. Quote Link to comment Share on other sites More sharing options...
speedyquest Posted October 22, 2014 Report Share Posted October 22, 2014 The only thing I see in your list that might be difficult to get ahold of is the 9.5:1 pistons. The other thing I notice is the idea of using an "eclipse" setup for doing an mpi car has only been done by a few people and only one that I know of personally. His car was right around 500 hp so I am in agreement with you, it shouldn't be hard to reach the goals your expecting. Keep in mind, I'm by no means an expert in this area(far from it in fact lol). Quote Link to comment Share on other sites More sharing options...
992gnt Posted October 22, 2014 Author Report Share Posted October 22, 2014 I'm sure the pistons would have to be custom, but I'd guess anything other than stock would be anyway. Good to hear there's some cars out there that are making good power, without being totally outrageous (whatever that means lol). Quote Link to comment Share on other sites More sharing options...
importwarrior Posted October 22, 2014 Report Share Posted October 22, 2014 i believe people are making that with the 8:1 wiseco's dad sells at www.enginemachineservice.comrather then modifying a DSM CAS to work just use a mighty max dizzy. it is basically the same thing.just need a spacer of .223 inch. Here is a link with pics and year make model of what Dizzy to use. http://www.starquestclub.com/forum/index.php?showtopic=113656&hl=%2Bdizzy+%2Bspacer Hope this helps. ALSO The YoshiFab high res disk for megasquirt will help as well. http://yoshifab.com/store/index.php?_a=viewProd&productId=46 Quote Link to comment Share on other sites More sharing options...
992gnt Posted October 22, 2014 Author Report Share Posted October 22, 2014 Thanks for the links. The plan is coming together... 8.1 just seems... so low Quote Link to comment Share on other sites More sharing options...
importwarrior Posted October 22, 2014 Report Share Posted October 22, 2014 I agree. I personally would like 9:1 myself. Quote Link to comment Share on other sites More sharing options...
speedyquest Posted October 22, 2014 Report Share Posted October 22, 2014 Sadly there just isn't a lot of mainstream performance parts built specifically for our cars. So get ready for lots of custom parts or dealing with what we do have available. Quote Link to comment Share on other sites More sharing options...
Dad Posted October 22, 2014 Report Share Posted October 22, 2014 I can get the same pistons made in a flat top, same price. approx 3-4 weeks and must be paid in advance. Sets of 4 or more only. Dad Quote Link to comment Share on other sites More sharing options...
992gnt Posted October 23, 2014 Author Report Share Posted October 23, 2014 Same pistons? Cost? Quote Link to comment Share on other sites More sharing options...
Dad Posted October 23, 2014 Report Share Posted October 23, 2014 http://www.enginemachineservice.com/ems/parts/conquest/pistons.php Quote Link to comment Share on other sites More sharing options...
992gnt Posted October 23, 2014 Author Report Share Posted October 23, 2014 Are you referring to a 9.5:1 piston? That's the route I would like to go. I'm not sure why the trend is to go with such a low cr, custom pistons cost the same regardless of the cr (for the most part). Quote Link to comment Share on other sites More sharing options...
importwarrior Posted October 23, 2014 Report Share Posted October 23, 2014 stock the car is 7:1 so 8:1 is definitely an upgrade. 9:1 i don't honestly know anyone running above that. Quote Link to comment Share on other sites More sharing options...
JAinsworth Posted October 23, 2014 Report Share Posted October 23, 2014 You know that the compression ratio increases under boost? 9.5 may be more than the rest of the engine can handle.Jimmy Quote Link to comment Share on other sites More sharing options...
992gnt Posted October 23, 2014 Author Report Share Posted October 23, 2014 I'm aware of that, yes. I'm asking the question to find out why no one has done it. Maybe the rest of the engine can't handle it. Maybe no one has tried. Maybe they tried to do it with the TBI and distributor and couldn't control ignition and knock retard well enough to keep it alive. No one has said any of that yet, so i'll keep asking. Quote Link to comment Share on other sites More sharing options...
JAinsworth Posted October 23, 2014 Report Share Posted October 23, 2014 Contact Bad2rass, he tried 9.0s and promptly blew the engine.Jimmy Quote Link to comment Share on other sites More sharing options...
MikeMeyerhoff Posted October 24, 2014 Report Share Posted October 24, 2014 The G54b is a non-interference design. Higher compression can change that and takes more effort to pull off since you have to account for where/when valve movement. That's probably the biggest reason. Most people don't want to get that involved into it and just use more boost to get to the same final compression. Quote Link to comment Share on other sites More sharing options...
992gnt Posted October 24, 2014 Author Report Share Posted October 24, 2014 But the benefit of a higher cr piston to power under the curve is real. Turning up the boost is easy, but I've never done things the easy way. Quote Link to comment Share on other sites More sharing options...
MikeMeyerhoff Posted October 24, 2014 Report Share Posted October 24, 2014 Please don't take me as arguing either way, just point out why its not more common. Quote Link to comment Share on other sites More sharing options...
992gnt Posted October 24, 2014 Author Report Share Posted October 24, 2014 I didn't take it that way at all. Quote Link to comment Share on other sites More sharing options...
importwarrior Posted October 24, 2014 Report Share Posted October 24, 2014 If you Get a chance talk yo starquestrescue.He has possibly the most data log information on this site.He can show you screen shots on just about anything you need to know.He is the TBi king for horsepower. 4cylfury ran a 5.9x in the 8th with a stock head no port work on the head.Valve and valve springs I have no idea but it is a stock head.Go to war stories to see his vids. Some great runs. Quote Link to comment Share on other sites More sharing options...
Malykaii Posted October 24, 2014 Report Share Posted October 24, 2014 Plenty have done higher compression on the g54, just,not here. There's a 20 page thread called the turbo swap bible and plenty of documentation in the early days of swapping station stuff into monteros. Many got creative or lazy and tried to just bolt on the intake and exaust manifolds to the n/a block with 8.7:1 cr. Results were always meh. Some even began to mess with recalibrating the ignition curve with different springs for the distributor, and still no go. You do bring up that it can be throttle body issue and with a fully programmable trimming curve it might work... But why. I see you want to shoot for reasonable power levels and sounds like you have the funds to do it... So why not stop peeing against the wind and do it right. Sure you could prove a point that it can be done but at the end of the day it's a 30 year old fork lift motor. Plus it's bolted to transmissions that barely last at stock power. Hell I had a km series trans die on me in my 90hp suv. Why not just engine swap and be done? Quote Link to comment Share on other sites More sharing options...
992gnt Posted October 24, 2014 Author Report Share Posted October 24, 2014 Why not? I'm not out to prove anything to anybody. I have a spare 4g63 on a stand. Easier? Maybe. More fun? Unlikely. The road less traveled is always more interesting, at least for me. Swaps are cool, don't get me wrong, but I do like being different. Quote Link to comment Share on other sites More sharing options...
87redcat Posted October 24, 2014 Report Share Posted October 24, 2014 Well I can say that you are on the path for being different by just owning a quest. I say if you want the challenge then go for it. Like you said, do the math, before hand so the head doesnt blow off. Quote Link to comment Share on other sites More sharing options...
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