LGM Turbo Group Buy - Start Shipping Out Yeah

[Denny]

i would PM Marie or Ekkers. who knows, she might have a spare or be willing to make you one.

I've already tried; they have no spares and are not planning a 2nd run

[CRAMBURY RS]

i would PM Marie or Ekkers. who knows, she might have a spare or be willing to make you one.

I've already tried; they have no spares and are not planning a 2nd run

if someone can send me the stock intake pipe, i can probably fabricate something for you. may not be as BLING since it will be welded and not mandrel bent, but it will work.

[lotusgirlmarie]

4th run list started a few days ago

[Ekapol]

Here is the link to the page:
LGM Group Buy - BOV/Turbo Intake Pipe

Sorry for the inconvenience. The other thread was still under "Turbo" section.

[CRAMBURY RS]

sweet! problem solved

hey Marie, have you had any issues with your octane rating being too low for the amount of boost you're running? just curious if you have had any detonation issue at 18 psi. i'm hoping to run 22 psi next year and have considered an E85 and 92 octane mix.

[CRAMBURY RS]

wow, no replies in months! anyhow, i'm looking at custom cams to compliment the GT series upgrade. there is a mild, mid and wild grind offered. i'm strongly considering a 218/.350 (duration in degrees/lift in inches) mid range cam that will idle well but increase both flow and the expand powerband by about 1500 RPM. the grind is an increase from 202/.322 in the RS. does anyone have the M100 cam specs?

thanks!

[abmunro]

Well I've had chance to drive my car a bit now and here are some of my thoughts.

I am a bit dissapointed in the Turbo lag to be honest and wished I'd gone for smaller turbo.

It comes on full boost at 4500 rpm and is at 6500-7000 revs in seconds.

So although when the car is on full boost its an absolute monster,LOL, Its only there momentarilly as you quickly have to change up a gear.

I guess the only way forward is forged pistons so you can rev higher.

I wont be making any wholesale changes as I spent to much already.

Any thought's would be appreciated.


Tony

[CRAMBURY RS]

Well I've had chance to drive my car a bit now and here are some of my thoughts.

I am a bit dissapointed in the Turbo lag to be honest and wished I'd gone for smaller turbo.

It comes on full boost at 4500 rpm and is at 6500-7000 revs in seconds.

So although when the car is on full boost its an absolute monster,LOL, Its only there momentarilly as you quickly have to change up a gear.

I guess the only way forward is forged pistons so you can rev higher.

I wont be making any wholesale changes as I spent to much already.

Any thought's would be appreciated.


Tony

an overbore would make the middle range a bit more exciting. Lotus/Isuzu makes .050" and .100" cast overbore replacement. some of the isuzone members have used them with great success at the 14psi the stock ECU and MAP are designed for. at .050" you gain a total of 52cc, which is 13cc more per cylinder of fuel/air in the block and eventually through the turbine housing.

it would a cost effective means of gaining response and some displacement.

second option is water/methanol injection. the vapor it creates should greatly improve spool.

[bobbrown]

an overbore would make the middle range a bit more exciting. Lotus/Isuzu makes .050" and .100" cast overbore replacement. some of the isuzone members have used them with great success at the 14psi the stock ECU and MAP are designed for. at .050" you gain a total of 52cc, which is 13cc more per cylinder of fuel/air in the block and eventually through the turbine housing.

it would a cost effective means of gaining response and some displacement.

second option is water/methanol injection. the vapor it creates should greatly improve spool.

Not sure where the 0.050" or the 0.100" came from but my manual states overbore sizes of 0.5 mm and 1 mm, may be confusion between metric and imperial but 1mm equals 0.0393".
This only gives a very small increase in CC such that at 1mm overbore you have an engine capacity of 1628 cubic cm which is only 10 CC per cylinder which is not significant and would have very little effect on spool up times.

I did not think water/methanol injection did much for spool up times and was done more to reduce the risk of detonation.

My understanding of turbo lag.

Lag is not just down to the size of the turbo as all turbos have some form of lag but the amount of lag can be greatly affected by the size of the turbo due to inertia of the rotating parts plus other factors.
Turbos need to be matched to the requirements in terms of HP and the more HP you want the more lag you are likley to get.
Let’s take a look at what happens when you go from high a power scenario to throttle closed.
The turbine is running at high speed when you are at high power, and pumping a lot of air and you then promptly shut the throttle, the poor turbo now has no where for the air that it is compressing to go so you can get into a stall position on the turbo. Ah! you say I have a dump valve fitted to stop this, fine on the air end but what about the exhaust side, that was running on high power with a nice positive pressure in the manifold and now the pressure has dropped even to the point of going into a high vacuum such that the exhaust turbine is now acting like a pump which cause the turbine to slow.
When you then need power you then have to bring the speed of the turbine back up which takes time hence the lag.
There have been many methods to overcome lag, some of which are not very kind on the turbo or the engine, the method of retarding the ignition and allowing fuel and air to pass through the engine and ignite in the exhaust manifold is one such anti lag system.
A better way is to recirculate the air from the compressor back into the exhaust manifold that coupled with some extra fuel can allow this mixture to ignite and burn in the manifold, this heat and pressure allows the turbine to spool back up and the compressor maintains the pressure in the air side.
Bit like allowing the dump valve to dump into the exhaust although I doubt a standard dump valve would survive the heat.
None of the anti lag systems are easy to implement and require work to both the air side and the exhaust along with the necessary changes to the ECU.

Bob

[CRAMBURY RS]

This only gives a very small increase in CC such that at 1mm overbore you have an engine capacity of 1628 cubic cm which is only 10 CC per cylinder which is not significant and would have very little effect on spool up times.

really? i don't see how it wouldn't. if every 2 full crank rotations you spit out another 40 plus cc's of compressed fuel and air into a turbine housing then at 2000 rpm you have ran another 10,000 cc's through each cylinder or 40,000 cc's through the turbine. the amount as little as it may be is exponential. the higher the rpm, the greater the overall volume.

in my case, i went .050" or 1.27mm, for a 52cc increase. i also removed anything emission related (pre-cat, cat, egr, charcoal can, etc) and am running 2.5" piping. oh, i also installed 218/.350" and 225/.350 cams :p

a video of the cams installed at idle
http://www.youtube.com/watch?v=73LrEQzNPuA

[bobbrown]

Still not sure where you get piston sizes of plus .050" and .100" as Isuzu are metric not imperial so why would they use imperial measurements.
You have to take a lot of things into consideration and an engine will never flow the theoretical value.
Even an increase of 52cc is only an increase of 0.033% so relatively small assuming 100% flow.
The engine at 2000 rpm flows a theoretical 1588 ltrs (do not forget it is a 4 stroke) your additional 52cc's only adds 52 ltrs.
Changing the cams may have a bigger effect on turbo lag than increasing the cc of the engine.
Cams can be used to good effect to change an engines characteristics but it takes a very significant understanding of a particular engine to get the most out of it and may take additional head work to see any major gains in power.

[CRAMBURY RS]

Still not sure where you get piston sizes of plus .050" and .100" as Isuzu are metric not imperial so why would they use imperial measurements.

i have custom forged pistons from arias through Robie the Robot. the dish is gone and replaced with valve reliefs.

i know that 3% doesn't seem like a high number, but i find it hard to believe it won't noticeably impact spool. even something like a 3% change in fuel to air can help the overall performance of the turbo's efficiency. the change in spool up may not be dramatic, like 500rpm, but if i can make fool boost 50-100 rpm sooner it's enough to pull the car .01 seconds closer to desired 12 second goal

granted, i have tried to make the best of my overbore to increase flow. i probably see a greater increase in spool from the exhaust, intake, cams and porting than the displacement...but ever little bit helps

[addict]

if you can find the jmr site thats johnmayerracing there is an engine calc on there borex stroke x number of pistons =cc
or 90.5mm pistons x 69mm crank x 4 pistons =1776cc .

[addict]

maybe the 1800cc engine has a longer stroke crank this with some shorter pistons would give more cc

[CRAMBURY RS]

maybe the 1800cc engine has a longer stroke crank this with some shorter pistons would give more cc

the 4xe1 (1.6) and 4xf1 (1. have the same bore, but the rods and crank are different. the pistons are also different, with the center of the wrist pins being higher (if i remember right) in the 1.8 and the type of pins are also different. you can not swap the crank assembly either because the main bearings are smaller in the 1.8 than the 1.6 engine. it would be easier to turbo a 1.8, but the cost/availability of bearings, rods and pistons will break the bank

[bobbrown]

i have custom forged pistons from arias through Robie the Robot. the dish is gone and replaced with valve reliefs.

If you remove the dish then you must be running the pistons with a lower deck height to get the same CR assuming the cylinder head combustion chamber is the same size as standard, and I thought it was better to run with the dish as it does give a better burn and thus more power.

std piston.jpg (15.24 KiB) Viewed 35609 times

[CRAMBURY RS]

they look like this now:

and yes, those are ARP rod bolts


the removal of the dish causes the intake stroke to compress the fuel and air into a smaller area (cyl head chamber) before ignition. it also requires higher octane levels to keep it from detonating early.

[addict]

if the heads not been brought closer to the crank by skimming the block you will have a lower cr . unless the rods are longer moving the piston up the bore .
what is your deck hight what is the cc volume of the piston at tdc . size of the piston in mm stroke of the crank .do you have a dish in the cyl head if so what cc.
you can then calculate your cr .
changing you rod ratio can cause your engine to rev differently . but longer rods will reduce the side load on the piston

[racerstev]

I was just reading the manual agein. It list the pistons as being forged and the crank as being cast.
Both are wrong..

[CRAMBURY RS]

M, did you have any left over parts? oil lines, water lines, etc...thanks