GT74 High Compression Six Speed

[MartinBattye]

its got an its gt74.. it doesnt need bigger injectors.. it doesnt need a new ecu to make more power.. it'll be knock limited before it maxes injectors out anyway.

 

it needs less fannying about..

 

it also doesnt need certain business men ramming a product deep into phils bottom.

[JamieP]

What injectors are you on now and what are you thinking of upgrading to Phil? you still coming to japfest?

[SupraHuman]

I can't wait to hear your car fire up. If it is OK with you and Martin, I will take my new HD camera up to the workshop and get some video clips of the event.

 

Yeah sure Phil, you're more than welcome mate, make sure you get some close ups of when i fill my nappie

[Terminator]

I decided to take the plunge and start running a jet of 50/50 water and methanol, to aid lower charge temperatures and ward off det, which is always going to be slightly more of a risk with my engine. Not sure yet whether to factor it into the map or just keep it boost triggered to give a bit of head room on an already safe map.

 

I am installing a Cooling mist system with a jet capable of cooling up to 1000bhp, the location of the tank and pump is temporary. If it all works out as I planned I will mount the pump separate from a new custom water/meth tank, I will make for one of two possible locations. I have added few pics of what can be done instead of watching football, apparent there was a little match on this evening.

 

 

Initially I will use the boost pressure switch to switch on the pump at 0.5 bar, dependant on how things turn out, I may use the ECU to control it with a combination of factors causing the pump to trigger.

 

Pump and 1.5 gallon tank tested, boost switch set to 0.5bar.

 

The little loom I made up to power the pump with feed from the boot battery.

 

 

Fuse and relay.

 

 

 

My jump pack ran out of juice so I could not get a shot of the spray atomisation from the nozzle at 150 psi. Will post images when the pump is getting a full 12volt supply.

[Guest niteryder]

Any idea on mapping date yet? Would like to come along if I'm not working.

 

I fear I may have to supercharge the Vette to keep up ha ha.

[Terminator]

Any idea on mapping date yet? Would like to come along if I'm not working.

 

 

Not sure, not too long now, I have changed all the fluids and flushed out my oil cooler ready for mapping. I want the water/meth system up and running and capable of dealing with up to 1000BHP. The simple boost switch will be fine for now, but later I want to control it via the ECU.

 

I have run the boost and water/methanol pipes from the boot through to the engine bay. For those that don't know, there is loads of room for additional wiring pipes etc in the channel under the passenger side door seal.

 

 

I considered running the lines under the car, but thought the plastic may be a bit vulnerable to stone impacts so choose the interior route. This will also make plumbing in a custom tank much easier. The tail gate washer feed takes the same route as standard, so I have no qualms about running water/meth inside the car. Only mixes above 50% methanol are flammable, I plan running 25% to 40% meth mixes.

 

[JamieP]

Whats the plan to get to a 1000bhp mate? gonna push your turbo as hard as you can or go with something bigger?

[Terminator]

Probably go bigger at some point, water injection is a way for me to push the high compression limit on road fuel, so building a system that will support 1000bhp is just future proofing and the cost difference is negligible.I originally rejected WI, as the systems were too small to cope with big power, the pumps were just gutless and not worth risking an engine.

 

I want to maintain the linearity of power delivery, rather than going for all top end power. If getting 1000bhp means loosing lower level performance, then I don't want it. I draw the line at having a car that has poor off and low boost performance, just for the sake of the four figure horse power. I am not fan of lag, one reason why I took the high risk approach of high compression.

[Terminator]

While waiting for a high pressure pump for my Water/meth system. I decided to sort out my HID's by getting all the ballasts and cables mounted out of sight and upgrade my yellow halogen fog lights to 6000K HID's.

 

The big problem when fitting HID's to fogs on the supra, is the fog light electrical connections. You just can't fit all the wires in behind the lamp and shut the cover. Getting the HID watertight is the only way to go if you want HID fogs. You can't use the silicon disc gasket supplied with the HID's as the fog light opening in the MKIV lights is too big.

 

 

Inside the fog cover there is not enough room for all the wires on the HID kit.

 

 

 

Drastic action required, take out the whole headlamp, rip out all the old wiring and connectors and fit the HID cables into waterproof grommets. As little drilling out of the cable holes is required. Then fit some new waterproof plugs on the high tension side of the circuit.

 

 

Shutting the cover is still not easy due to the depth of the HID bulb and the gauge of the HID wires. Once shut the whole enclosure is waterproof again.

 

 

 

Now I have white fog lights.

 

 

 

I think it really updates the look of the front of the car having all four lights a crisp white.

 

Edited June 26, 2010 by Terminator (see edit history)

[Guest niteryder]

Terminator (phil) will be along shortly with an update.

 

That is after he has changed his nappy and had a cold shower.

 

Nice one Ryan. Good to meet you.

[JamieP]

Terminator (phil) will be along shortly with an update.

 

That is after he has changed his nappy and had a cold shower.

 

Nice one Ryan. Good to meet you.

 

Spill the beans:d did he make the 1000bhp?

Edited July 2, 2010 by JamieP (see edit history)

[Guest niteryder]

Think the gt74 will need swapping for that.

 

Wheel spin on the dyno was the limiting factor. Its at 1.4 bar now. It made 560 at 0.9bar. I think the plan is to get it on a hub dyno when Ryan is back from Australia.

 

It drives really well, power is smooth and seemingly endless.

 

We think it may be good for 1.7bar and around the 800's with the Gt74 and current injectors.

 

I think Phil is considering other turbo options. But that will be next year, once he has had time to enjoy this.

[Terminator]

Oh yes, now we are getting somewhere. Not 1000bhp Jamie, my 872cc injectors will push the GT74 to its limits. Yet another long boring post;), so skip to the end for pics and short version.

 

I have been having cold start and initial warm up driving issues with my car. From cold it was taking 3-4 minutes of driving and heel and toe at every junction and roundabout to keep the car running. Once this initial warm up was completed the car was fine. I remember Ryan mentioning that Seimens 872(83lbs) were prone to low duty issues on a resistor pack, so I switched to an AEM peak and hold driver pack, ready for a mapping session to get the most out of the set up. The P&H driver threw fuel duty in the map all over the place. Martins last minute re-trimming, on Thursday night enable me to start the car quite quickly first thing yesterday morning and for the first time drive quietly away early morning without having to heel and toe to keep the motor running, I am sure the neighbours we pleased. Cheers for your help Martin.

 

Got to the rolling road yesterday and almost immediately Ryan spotted a problem with my tires and rear arches. The 295’s, while fine on the road, were going to dig into the arches when the throttle was lifted after each power run. We only managed to get runs on the dyno in the high 500’s, we stopped after we found the first tell tale signs of clean rubber just below the shoulder on the tread. Due to the strapping down limitations, the wheels were just spinning up on the rollers. However Ryan had done enough for the final part of the map to be fine-tuned on the road. A print out from the dyno was pointless so we did not bother. To take it further on the dyno, I either needed narrower tires, not an option, rolled arches, or a hub dyno. I think the latter two both have advantages.

 

Without a paper print out, I know my figures don’t count on the forum, I don’t give dyno figures much credit anyway, for me it’s all down to feel and the clock, so I’ll leave Ryan to comment with his estimate if he has time to post here. We all like to talk the torque, but again I’ll leave it for Ryan to say how the car felt on the road, I will say he was impressed with the build quality and the performance of the car.

 

What did surprise me was we got a good steep power curve at 1.4 bar, Greddy gauge read 1.5. Ryan sees no reason why we should not take it to 1.7 on V power, as there was not a hint of knock during the whole session. We did not use water injection at all so the readings were all road fuel only. I am going to hook up the water injection to AEM so that we can do another map with AEM controlling the water injection to help with timing at the top end and extract even more power. So everyone who was telling me you can’t run a CR of 9.5:1 on a road fuel should note there are at least two cars with that CR on the forum LeeP and mine and they both make good power on road fuel. Also some doubt was expressed when I said in another thread that my EGTs don't go over 800 degrees, Ryan confirmed that during the whole session thrashing the motor for over two hours, 800 degrees was the highest they hit, water temps were a steady 80 during the session. Over all I am really please with the car.

 

 

My first ever dyno session.

 

 

Ready to roll

 

 

Ryan doing his stuff to the map.

 

 

Keeping a eye on the rears to stop them exploding.

 

 

Just visible the tell tale marks just beginning to show on the left rear. Does not look like much but not worth loading the car with more power and sinking right down into the tire, with potentially dire consequences.

 

Edited July 12, 2010 by Terminator (see edit history)

[dandan]

Well done Phil and Ryan

 

I think I may in the same boat as you with rear arches so I'm just waiting to get them rolled.

[TLicense]

Great stuff Phil.

[SupraHuman]

Good stuff Phil, car looks mint mate

[Terminator]

Good stuff Phil, car looks mint mate

 

Thanks guys, the car is actually quite scruffy at the moment, so I am going to give it a going over with G3 and then some Carnuba wax. I might have to air dry it after the wash.

 

I thought the 295's would be OK on the rear. The suspension is very firm and I have only once bottomed it out and hit the tire. Being a RR virgin I never realised home much the car reacts to the sudden release of torque at the end of a pull. Wish I had known so I could get something done before the session.

[SupraHuman]

Thanks guys, the car is actually quite scruffy at the moment, so I am going to give it a going over with G3 and then some Carnuba wax. I might have to air dry it after the wash.

 

I thought the 295's would be OK on the rear. The suspension is very firm and I have only once bottomed it out and hit the tire. Being a RR virgin I never realised home much the car reacts to the sudden release of torque at the end of a pull. Wish I had known so I could get something done before the session.

 

I got 295s on mine, what size is recommended for dyno tuning Phil? 275's??

[Terminator]

Get the arches rolled, Ryan advised widest rubber possible. I suggested putting my 255's front on the back but he said they would not hold the power.

[SupraHuman]

Get the arches rolled, Ryan advised widest rubber possible. I suggested putting my 255's front on the back but he said they would not hold the power.

 

Sound, my arches are already rolled mate, will ask Martin to check them again for clearence.

Edited July 3, 2010 by SupraHuman (see edit history)

[Terminator]

I think you should be fine, I think 1/4 inch off my arches and there would have been no issues. It was that close. But not worth finding out.

[jevansio]

Nice work Phil, love the way you have kept the exterior subtle too

[dandan]

Phil what is the width and offset of your rear wheels and are the tyres 295/30/18?

[Terminator]

Now you are asking, I'll have to do some digging. Tires are 295 35 18

[SupraHuman]

Phil what is the width and offset of your rear wheels and are the tyres 295/30/18?

 

My 295's on 19"x10" has a 41 offset.