TECH TALK - ask your technical car questions

[steelsnake00]

How much of the XR3 parts are you using?
The drivetrain is probably knackered, that or the gearbox
Just bolt in an XR3 'box and it should be ok...

[HKS]

I'm using the complete enjin plus gearbox.
Coudn't it just be that its a vacuum problem?

[steelsnake00]

It sounds like a drivetrain problem, if the engine is revving freely then its gonna be a drivetrain or gearbox problem. If you are running the GLE drivetrain, I would try and cutsom a cut-down XR3 drivertrain and differential onto it. Check your clutch (better safe than sorry...), if not then it might well have something to do with your 'box, probably some minced cogs.

One of my friends is suggesting that the fuel pumps are starving the engine of fuel when under stress, or the oil pump it too weak to correctly supply the engine. A similar things happened to his boat...

[HKS]

thanx alot steelsnake, i'll check it out this w-end.I hope its not the drivetrain or gearbox.

[Grez~Supra_RZ-S]

Running it on a chip or bespoke ECU?

Its a Stage 2 chip, basically a piggy-back ECU.

As much as I love my SX, its being sold soon due to money problems. Ive already sold my Del Sol, and bought an Aw11 MR2 as a daily driver until things get themselves sorted again.

Here's the prognosis-
When the car is not in gear i can rev it all the way up to redline(6800 rpm) with no problem,
but as soon as i drive aroud the revs will not go above 3000rpm,is makes a noise like its starving of something with a lot of spluttering.

Anybody hav any idea what this might be

It sounds like your engine is on 'get me home' mode, and I had similar problems with my Del Sol.

There are numerous problems it could be, but the most likely is a vaccuum leak, most likely to be a split hose. However, it could also be a cracked inlet manifold, or some blown gaskets.

It could also be that the timing has been knocked out slightly (which is what happened with mine), and your engine is cutting the amount of fuel going into the engine to be on the safe side.

[steelsnake00]

Didn't think of that Grez, thanks
Another question, was the XR3 engine straight out a running XR3 or a scrap car?
If its scrap then that would explain the damage.

[HKS]

Its not a scrap enjin. But some of the hoses are a bit dogdy, so i think i'll replace them all.
Its not the gearbox,put another 1 on this w-end and still doing it.
Anbody know the timing for a 1982 XR3 CHV 1600 enjin? i'm still waiting for my mate to print me a manual.

Thanx so far guys

[HKS]

Last update:
The car is running almost fine now,
only thing it likes to do is to start backfiring above 2800 rpm if its not on normal operating temp,
any ideas anyone?

[Peter Ferrell]

I'm just wondering, in a little while I will be eligible for driving... (Heh heh heh...) Just wondering regarding my first car, whether it is possible to convert a 4 door car into a 2 door? Any answers, please respond...

[boganbusman]

I'm just wondering, in a little while I will be eligible for driving... (Heh heh heh...) Just wondering regarding my first car, whether it is possible to convert a 4 door car into a 2 door? Any answers, please respond...

Yes it's possible, but it's a very difficult operation. To do it yourself would require expert engineering and welding skills, and a lot of effort and time. To get someone else to do it would cost a lot of money.

Also, I would never consider a major modification like that for a first car.

[HKS]

You could also just weld the back doors shut and then u hav a 2 door J/K

Side note: Fixed the problem with the escourt, was a bad electrical connection betweeen the battery and chassis,
Thanx 4 all ur help guys.

[79 RS]

I'm just wondering, in a little while I will be eligible for driving... (Heh heh heh...) Just wondering regarding my first car, whether it is possible to convert a 4 door car into a 2 door? Any answers, please respond...

It would be far easier to get a 2 door car, espcially when it available as 2 or 4 doors

[SkeeteRX7]

Ok, here's a problem.

My friend in Chicago is building a Caterham Seven. He's been asking me for engine suggestions, for 4-cyl, 6-cyl, rotary, and 5-cyl. Here are some I picked, can you guys give any suggestions?

4-cyl:

Honda K20Z1 (Acura RSX Type S)
Mazda MZRL3 (Mazda 3 S)
Nissan QR25DE (Nissan Sentra SE-R Spec-V)
Toyota 2ZZGE (Toyota Corolla XRS)
Nissan SR20DET (Nissan Silvia S15 Spec R)
Mazda BPT4W (Mazdaspeed MX-5 Miata)

6-Cyl:

Toyota 2JZGE (Lexus IS300/Toyota Alteeza)
Nissan VQ35DE (Nissan 350z)
Honda J32A3 (Acura TL)
Mazda KJ-ZEM (Mazda Millenia S)
Nissan RB20DET (Nissan Skyline (R32))

Rotary:
Mazda RE13B-MSP (Mazda RX-8 SE)
Mazda RE13B-RESI (Mazda RX-7 FB)
Mazda RE12A-T (Mazda RX-7 FB)
Mazda RE13B-VDEI (Mazda RX-7 FC)
Mazda RE13B-T2 (Mazda RX-7 FC)
Mazda RE13B-REW (Mazda RX-7 FD)


So, what d'you guys think?

[steelsnake00]

Caterham Seven's are only sold (pre-constructed) with 4-cyl engines besides one model, the Super Seven, which is V6 powered. A Rotary engine would be difficult, and longevity is always a problem. What kind of budget is he looking at? And why have all the engines you've chosen come from Japanese cars?
Personaly, I'd go with a 3L-ported and lightly modified 2.8l 24v VR6 from a MK4 Golf 4-Motion. An easy 250bhp from a lightweight, part-aluminium VW block that has a reputation for out-lasting the rest of the car. You can't really go wrong. And anyway, if that isn't enough power, you could always dump in a Golf R32 motor or supercharge it for 350whp+!

[SkeeteRX7]

Caterham Seven's are only sold (pre-constructed) with 4-cyl engines besides one model, the Super Seven, which is V6 powered. A Rotary engine would be difficult, and longevity is always a problem. What kind of budget is he looking at? And why have all the engines you've chosen come from Japanese cars?
Personaly, I'd go with a 3L-ported and lightly modified 2.8l 24v VR6 from a MK4 Golf 4-Motion. An easy 250bhp from a lightweight, part-aluminium VW block that has a reputation for out-lasting the rest of the car. You can't really go wrong. And anyway, if that isn't enough power, you could always dump in a Golf R32 motor or supercharge it for 350whp+!

I suggested an VR6 engine........but he (for some stupid reason) hates VW.

All are Japanese because he can get Japanese engines cheapest from his father's business connection in Tokyo.

[steelsnake00]

Then he's a fool, no offense. You can pick up a running 12v VR6 (192bhp) for about $300, and about $500 for a 24v 210bhp one.
How about a BMW S50B32 from a Euro-M3, or the S50B30 from a US spec one? An easy 250bhp+ there...
Or you could go for the 350Z engine...

[MarlboroMan]

sorry but i dunno much about americans engines, but some of my ideas might be useful
space/size:
well, why do you think the rotary engines are long ? rotary engines are relativly compact compare to the piston based engines(dont be fooled by the small displacement of rotaries, if calculating actual displacement 13B might be 1.3L X 2 = 2.6L, just they count 1 active combustion area instead so its a 1.3L global), i mean really long engines are the inline-6 piston based when you want to set it up to a FR layout, fitting radiator, radiator fan, and if it is turbo charged you gottan figure out where to stick that big chuck of intercooler in the front bumper with resonable streetable capability, air condition condensor and other piping may require some space...

performance/tunning oppurtunity:
in asia (where am i now) K20s and 2ZZs are quite expensive. however if i were you i'd pick K20 over 2ZZ although similar technology (i-VTEC equivalent to vvtL-i), but there are more aftermarket support for K20! with a slight larger displacement, ideal square bore and stroke dimension 86.0X86.0mm (same as SR20, 6cylinder 2JZ, McLarenF1)that will give reasonable torque. SR20 versus K20, same displacement same diemension bore/stroke K20 comes in i-VTEC (VTEC+similar to toyota vvt-i system) where some SR20 variants may come with turbo stock, SR20VE thats the rare one will have VTEC equivalent mechanism stock. much more rare if you are in luck...SR20VET its basically a SR20VE + turbo stock form (only 1 nissan model used it that i recon which is the X-trail limited edition) goodluck finding one !

However you should be very clear are you going NA or force-induction, where the car streetable/practical in daily use or circuit/track usage factors 1st. i would like to chat about it more.

p/s: you seems pretty interested in rotary, if fuel consumption isn't an issue try getting the 3 rotor mazda 20B rotary, its an old engine but pack hell of a punch.

[steelsnake00]

Longevity is nothing to di with length. Longevity refers to the fact the damn things break all the time.
Plus, they're torqueless, guzzle fuel, have useless power curves, are expensive to maintain and run, and just aren't good for power really.
As an interesting side point, the Rotary engine is acutally based on a supercharger design.

[MarlboroMan]

ooops sorry for the misread and misinterpretation

uhh ? seriously ?
i thought rotary are less friction than piston based engines and less wear and tear effect because the rotor doesnt intersect with each other's rotational area to compress air&fuel mixture as in lysholm sort of superchargers/compressor (except for the centrifugals supercharger which is more like a turbo compressor housing design). maybe you are right, the only part that seperates the combustion chambers of the triangular shaped "piston" corner edge is of each side which all the force is concentrated at that particular point.

rotary engines indeed have the torque curve shoot up only at high rpm which is not any useful for low rev acceleration and daily driven. but high rev performance is very well indeed, 20B turbo should able to produce around 500horse with proper tunning, check out the best motoring [battle at 10k rpm] NA version of 20B RE amemiya RX7 that won the battle (of course that is proffesionally tunned case 360HP). if hunting for high rpm performance perhaps rotary can be taken into consideration.

[steelsnake00]

Two words

Apex
Seals


RX7 Turbo's have been known to go throug them EVERY 3 THOUSAND MILES.
If you want high revs, buy a bike. Car's are meant to have some lower range power too.

I shall give you an example. I drag race occasionally; my car, which has been posted in members, is an Audi S2 with a factory-fitted RS2 engine transplant, some goodies fitted by me (including a custom spearco water/air cooler, new cams and chipping, decat ect), and some minor drivetrain mods (flywheel, Sachs racing clutch, short shift). It's dyno'd at 384.6 (420ish at the flywheel) last run (at the wheels), and 406lb ft.

In a drag race, it's capable of a mid-12's 1/4ml. In essence, that makes it faster than your run-of-the mil,single turbo converted 20B RX7, which is good for somewhere between 450-500bhp.

The reason that the S2 is much quicker is not because of the 4WD system or any launch control tomfoolery, but sheerly because its got bucketloads of torque, and it hits its peak power at 5900 RPM. That means that I can double-clutch a gearchange and when I drop into the next gear (usually up to 4th in a 1/4, 3rd tops out at approx 100) and still be putting out peak power despite having dropped perhaps 900-1000 revs.

Horsepower is nothing without torque; ideally, you want more HP than torque to ensure that the horsepower it put to use rather than being wasted along the drivetrain.

The same is true of VTEC's. Yes, its possible to modify a VTEC to idiotic power, but as any percentage of that power is only avaliable at 5000+ revs, and all of it not til 8 or 9 thou; theres enough time to read a small novel before you reach your peak output. They lack torque, lack responsiveness. Though I'd disagree with the oldfasioned statement "there's no replacement for displacement" (there is, its called a Vortech RaceSpec blower or Garret G.T series), Rotary engines, though novel, are generally not as widely used as standard cylinder-based engines sheerly because they just aren't as good.

[MarlboroMan]

yeah exactly the word i am looking for to replace some of those i posted up there, the seals of the rotary indeed is a issue thats prone to damage.

yeah i totally agree with you for the horsepower and torque relation, horsepower is nothing without torque, it is torque taht revs, while horsepower is just the power output figure of the engine. an engine wont rev very well with low torque unless the car itself has very low mass, just like the F1 car, they can produced very high horsepower at extremely high rpm with the torque curve appeares at its peak point at very high rpm to maintain the rev response capability at that particular rpm range.

generally if you need high horsepower, the engine has to be able to handle high rpm (more workload revolution = higher power output) provided that the pitch torque of the engine appears at extremely high rpm also to push the engine revolution to go even higher.

horsepower is derive from the torque.

it is very knowledgeable and experinece of you steelsnake00, wish i could have this conversation with you longer and gain more knowledge to myself. please correct me if i am wrong.

[steelsnake00]

You've largely got it spot on; however, the comment about peak horsepower and higher revs isn't true; The rev range is merely the restriction put on the rotating mass of the engine. VTEC engines have high revs because their internals are light, whereas a big fat american 500s block would have very low revs as its rotating mass is enormous.
The power is actually provided by the equivilent chemical energy transfer by the explosion of the gasoline in the cylinders, contrasted with the rotating mass, speed and force of piston movement. Superchargers or turbos are not some magical all-in-one power increaser, because they merely provide more air into the cylinder; this in turn forces the fuel injection system to inject a varied fuel, meaning that the air/fuel mixture has a much higher volitility and will explode with more force when sparked. The increased force of this explosion is what requires engine pistons, connecting rods, gaskets ect to be reinforced to prevent damage. Horsepower, as a measurement, is actually torque/time (cant remember the exact equation), rather than a seperate measurement.

You seem quite knowledgable; if you are interested, my car is actually on Dragtimes. As of yet, there are no pictures of it however, as I got my registration email wrong.
Old, non-functioning link removed, pending update

[MarlboroMan]

hmm. interesting read. so the ristriction of rev range, do you mean the torque gaining point to the max torque rev range ? and about the rotational mass, is it the mass of the conrods + crank shaft + flywheel ?

yeah the force-induction at higher boost require i think those block guards, stronger studs, H-beam con rods and well balanced crank use those to stregthen the engine overall rigidity and to withstand the high explotion pressure in the combustion chamber.

based on your experience do you think a 9.0:1 compression ratio with around 1bar boost on a 92-96 closed deck H22A is able to withstand ? (with proper fuel feed and H-beam con-rods and studs)

oh yeah, the equation i found for torque horsepower relation is
1 horsepower = 33,000 lbft / 1 minute

[steelsnake00]

Oh, yeah, thats the equation.
The rotating mass is the weight of the pistons, cranshaft, camshafts, cam gears, flywheel, shafts, conrods; basically, anything that either rotates or is driven from the main shaft (cams). The restriction of the rev range is provided by the weight of the engine; a lighter engine will rev freer. However, this rule is somewhat discredited by manufacturers use of rev limiters to avoid engine damage. Though many of them are overly leinent; the camshafts and crank of an E30 M3 Evolution is built to withstand 11000 rpm (and in practice did, on Paris/Dakar and rally versions of the car), but for road-going versions was restricted to 6750rpm. There's also things like emissions and noise polution to consider.

My engine, though running at 20-21psi (depending on map and overboost settings), is still largely stock internals from a Porsche-engineered RS2 Avant. The spark plugs, some of the electics, and so-on and so forth. My camshafts are lighter, the sprockets are lightened and ballanced, the flywheel is a Sachs RS4 spec one (built to cope with bigger power). All rods and pistons are RS2, and the gasket and headers are MTM engineered from their similarly engined S1 Turbo Quattro conversions.

Based on my experiance, a Prelude could easily take 1bar boost at 9.0:1 compression, probably even on standard internals. However, to harvest the power most efectively seals, camshafts and clutch would need to be upgraded. If the boost was pushed up over 1.2 on the closed-deck engines, thats the point at which conrods would need upgrading. At 1bar, a Fuel Pressure Regulator and 550cc Injectors would be a good investment, whereas at 1.2bar+, you'd ideally want to be running uprated fuel rail and possibly uprated fuel pumps.

Bear in mind that VTEC engines do not get the same kind of performance boost as other engines from forced induction; as their rotating mass is smaller, torque and power figures start to suffer once the boost goes above 1.2 bars, certainly in relation to a I6 or V6/V8 engine. And with VTEC's lack of low range power, running a lower-boost supercharger would probably be the best way of shortcutting the lack of power until 3500rpm, by which time the Turbo would kick in.

[MarlboroMan]

yeah that pretty much clear out my doubts.

nice setups you have there. in my country the continental cars are extremely expansive! we hardly rich enough to own one of them unless those that making big business, cause the gov is charging 100%-300% tax on continental cars depending on thier luxury-ness. that pretty says that if we buy 1 of the cars the gov earn 1-3 cars equivalent. thats why my country is dominated by japs and koreans and of course some local-assembled cars which has alot less tax.

1 last question please. this is my scenario ..... so the 9.0:1 CR on the H22A that running 100kpa of boost (around 1 bar), i am planning to put a mid to small size turbo with acceptable lag when off boost, thats why i am picking a 9.0:1 piston mid boost instead 8.5:1 with lost of boost. i've read the http://www.turbobygarrett.com about the turbo selection pages and able to make some calculation and read the compression flow map of the turbos. so i am thinking about the GT2860RS (which is mid-small size in my opinion), which i hope the car start to build up boost quite quickly at around 2000rpm and reach max boost at 4000rpm with proper ECU mapping A/F and optimize with lambda meter.
so is the turbo is able to be quick spool as i spoken ? and does RON97 (pretty much PON93) is able to withstand the 9.0:1 with 100kpa @ ~1bar ?

i am planing to run on a safe side, i am not a racer . i will still upgrade the conrods, studds and those even on 100kpa.