GT74 High Compression Six Speed

[Miguel]

Great news Phil, always had faith in the higher CR route. Hats off to Ryan on another fine job.

[Lee P]

Well done Phil, I love my High CR engine. We got to 1.5bar (over 700hp) on pump fuel with no det on mine.

[Terminator]

Thanks guys. Love this HCR engine too. Thanks to Miguel for showing me the way to HCR, you always said it would create a very different driving experience, you were 100% spot on the money with that one.:D :thanku: There is no way I would go back to stock compression now.

 

From what Ryan estimated, based on work that could be done on the rollers, we achieved 700 - 750 on a fresh tank of V-Power. Not sure if that was at 1.4bar or 1.5bar, too many numbers flying about at the time. He did say there was loads more to come and that it built power very well. I hope for 800+ on the GT74DBB turbo and Seimens injectors.

 

As a road car it is awesome it just pulls and pulls all the way to the to 8400 or so. One thing I have noticed, holding WOT on the road EGT's are in the 700's measured in runner 6, which is a staggering result for HCR. With the added benefits of water injection we should be able to use timing to push the power even further as the engine design seems to keep EGT low unaided.

 

So far a couple of passengers have felt quite ill at the end of a WOT run:innocent:

Edited July 13, 2010 by Terminator (see edit history)

[Wez]

Nice work, must be a bit of an animal

[Ryan.G]

 

So far a couple of passengers have felt quite ill at the end of a WOT run:innocent:

 

Can understand why!!!

 

With the auto diff it really throws you back!

[DARETT]

Great project Phil, just read through the whole thread and it sounds like an amazing setup.

[Terminator]

Thanks for the comments guys. I am just loving how the car drives. It is all I wanted it to be. I thought it would be a bit of a handful/animal and it is, but its so drivable. RLTC has been switched off since mapping with Ryan. The HCR/HRPM/V160/Auto TT diff combo is an awesome package, which I would recommend.

[Luxluc]

Impressive result Phil.

[Terminator]

Decided to give my turbo a better fitting jacket.

 

 

 

As the previous jacket covered much of the down pipe, I have covered the clutch master cylinder shield with self adhesiv, fibreglass backed foil to reflect some of the heat radiating from the down pipe.

Edited July 16, 2010 by Terminator
Text removed old turbo jacket sold (see edit history)

[MartinBattye]

Can understand why!!!

 

With the auto diff it really throws you back!

 

i hear you were quite complementary about the car and the base tune..

[Terminator]

I have been getting loss of power at 1.3 bar and above on WOT, this started on the way back from SRR. l was almost certain this was down to fouled plugs, due to the injector map changes, caused when I changed from UK resistor pack to AEM peak and hold drivers. What started as an occasional miss, was developing into a more consistent misfire under higher boost on WOT. The spark was too weak and was being snuffed out.

 

I replaced the fouled plugs with a new set of BKR8EIX Iridium plugs with, out of the packet gaps. I had to wait for the roads to dry out to test the car. Result, no miss all the way to 1.5bar and 8500 rpm on WOT.

[RobD]

Superb result bud, looks a real beast!

[Nodalmighty]

Good result that.

 

On the subject of high CR's. There was a chap at ProDrive who was a serious water injection head. He did a 12:1 @ 3 bar clio engine that didn't det (It lifted the head and pissed water everywhere, but it didn't det ).

 

I'll looking forward to seeing what Fearless's 10.4:1 turbo V8 is going to do.

 

I did a Super charged 1mz-fe with 10.5:1 @ 9 psi and was suprised how much timing it would take. HCFI is the way forward.

[MartinBattye]

its all about cam choice.

 

static CR means nothing really apart from a number to quote..

[Chris Wilson]

There's another ongoing discussion about supercharged engines and CR on one of the Skyline forums, seems martin and I agree on the lack of importance of static CR over dynamic

 

http://www.gtr.co.uk/forum/139488-rb26-higher-compression.html

[Terminator]

It would be interesting to know the dynamic compression ratio of a stock motor with stock cams ie 233 UK spec , 224 J spec. Also the effect on DCR of the usual 256, 264, 272 cams of choice on a stock engine.

[Ryan.G]

i hear you were quite complementary about the car and the base tune..

 

Indeed but its even better now

 

One thing it needed the most was More Timing !! Can tell you work alot with rotarys being really cautious with timing. What det cans do you use as i gained about 70hp at just 1bar!!

 

Also use the intial crank pulse table otherwise you dont have a manifold wetting pulse and the car will take a while to start on cold. Both maps i have seen of yours didn't have this and took ages to start.

 

Either way lifes too short to bitch but you did take the piss on the suprahuman build thread.

 

Ryan

[Krister]

Great result Phil. I'd keep an eye on the AEM peak & hold driver though and swap it for something else. I've read alot of them fail and one cost my friend his engine.

[johnny g]

DCR is all I've read about for the last 3-4 days. It's a fascinating way of looking at things. Very much looking forward to some investigations with a view to doing my own!

 

Would it be worth starting a new thread with all of the cams information that we can muster to work out the DCRs?

[MartinBattye]

Indeed but its even better now

 

One thing it needed the most was More Timing !! Can tell you work alot with rotarys being really cautious with timing. What det cans do you use as i gained about 70hp at just 1bar!!

 

Also use the intial crank pulse table otherwise you dont have a manifold wetting pulse and the car will take a while to start on cold. Both maps i have seen of yours didn't have this and took ages to start.

 

Either way lifes too short to bitch but you did take the piss on the suprahuman build thread.

 

Ryan

 

the tune put on would be regarded as a safe basetune (i would say about 6-8degs retarded at a guess) for the road to get it running ok.. not by anymeans a power tune (as there where engine worries to start with, and at the time phil hadnt even got the hang of manual trans!)

 

 

that tune was done about 2-3years ago now i think. i know the table you mean too...

 

ive only mapped 1 rotary motor!! lol.. (most powerful in europe)

 

bitching aside... my IAT table made sense... lol only messing.

[MartinBattye]

Great result Phil. I'd keep an eye on the AEM peak & hold driver though and swap it for something else. I've read alot of them fail and one cost my friend his engine.

 

i;d agree on this too..

 

PPI supra had this exact problem on dyno recently! cured with a GTR res pack and some pushon crimps!! ghetto

[MartinBattye]

DCR calcs are a bit of a secret.... there is always tons of talk, but no noones that actually knows will say anything.. me included

[tDR]

DCR calcs are a bit of a secret.... there is always tons of talk, but no noones that actually knows will say anything.. me included

 

http://www.wallaceracing.com/dynamic-cr.php

 

 

Part of the tuning is 'black magic' brigade are we? You must be extra speshul to understand this stuff.

[johnny g]

Nice to see the culture of sharing is still going strong, cheers tDR.

[Ian C]

DCR calcs are a bit of a secret.... there is always tons of talk, but no noones that actually knows will say anything.. me included

 

Thanks for your contribution